ADC Written Exam — Questions and Answers

Question 1: Volumetric polymerization shrinkage in typical dental composite resins is approximately:

8–12%
0.1–0.5%
1–5% (Correct answer)
15–20%

Correct answer: 1–5%

Most composites shrink 1–5% by volume during free-radical polymerization as van der Waals gaps between monomer molecules are replaced by shorter covalent bonds, generating internal stresses at the cavity margin.

Question 2: In treatment planning for a patient with multiple failing restorations and active caries, which phase should be completed first?

Surgical phase
Definitive prosthetic phase
Disease control (stabilisation) phase (Correct answer)
Aesthetic phase

Correct answer: Disease control (stabilisation) phase

The disease control (stabilisation) phase addresses active disease — caries removal, infection control, and extraction of hopeless teeth — before any definitive treatment.

Question 3: Which root of the mandibular first molar is typically broader buccolingually?

Mesial root (Correct answer)
Lingual root
Distal root
Both roots are equal

Correct answer: Mesial root

The mesial root of the mandibular first molar is broader buccolingually and commonly has two root canals.

Question 4: Which of the following is the MOST important consideration when sequencing a dental treatment plan?

Aesthetic concerns should be addressed first
Emergencies and pain relief must be managed before elective care (Correct answer)
Prosthodontic work should begin at the first appointment
Orthodontic evaluation precedes all other treatment

Correct answer: Emergencies and pain relief must be managed before elective care

Treatment sequencing should prioritize emergency care and pain relief first, followed by disease control, then definitive and elective restorative treatment.

Question 5: A patient presents with trismus, fever, and a submandibular swelling that is crossing the midline. What is the most likely diagnosis?

Ludwig's angina (Correct answer)
Lateral periodontal abscess
Pericoronitis
Salivary gland obstruction

Correct answer: Ludwig's angina

Ludwig's angina is a rapidly spreading, bilateral, severe cellulitis of the submandibular and sublingual spaces often originating from a lower molar, presenting with trismus, fever, and bilateral floor-of-mouth swelling.

Question 6: In the instrument reprocessing workflow, what is the primary purpose of the initial cleaning step before instruments are placed in a thermal disinfector or steriliser?

To physically remove bioburden such as blood, saliva, and tissue. (Correct answer)
To fix proteins to the instrument surface for easier removal later.
To apply a protective coating to prevent corrosion during sterilisation.
To achieve high-level disinfection of the instruments.

Correct answer: To physically remove bioburden such as blood, saliva, and tissue.

Cleaning is the most critical step in instrument reprocessing. Its function is to remove all visible organic and inorganic material (bioburden). If bioburden is not removed, it can shield microorganisms from the sterilant (e.g., steam), leading to a failure of the sterilisation process.

Question 7: When preparing an access cavity for a mandibular first molar with a vital pulp, the ideal outline form is typically:

Trapezoidal or rhomboidal, located in the mesial half of the tooth (Correct answer)
Circular and centred on the occlusal surface
Triangular, with the base towards the mesial
Oval, oriented in a mesio-distal direction

Correct answer: Trapezoidal or rhomboidal, located in the mesial half of the tooth

The ideal access cavity for a mandibular first molar is trapezoidal or rhomboidal in shape. This form reflects the underlying anatomy of the pulp chamber, which is wider mesially (to accommodate the mesiobuccal and mesiolingual canals) and narrower distally (for the distal canal(s)). The outline is confined to the mesial half of the occlusal surface to conserve tooth structure while providing straight-line access to the canals. A triangular shape is typical for maxillary incisors, while an oval shape is more common for premolars.

Question 8: A periapical radiograph of a maxillary first molar shows the palatal root superimposed over the distobuccal root. A second radiograph is taken with the X-ray tube head moved more mesially. In this new image, the palatal root now appears distinctly mesial to the distobuccal root. Based on the SLOB rule, what is the buccolingual position of the palatal root?

It is buccal to the distobuccal root
It is directly in line with the distobuccal root
It is lingual (palatal) to the distobuccal root (Correct answer)
Its position cannot be determined with this information

Correct answer: It is lingual (palatal) to the distobuccal root

The SLOB rule states 'Same Lingual, Opposite Buccal'. The X-ray tube head moved mesially, and the image of the palatal root also moved mesially relative to the distobuccal root. Since the object of interest (palatal root) moved in the 'Same' direction as the tube head, it must be the 'Lingual' (or palatal) object.

Question 9: A 58-year-old male patient presents for a periodontal maintenance appointment. He completed non-surgical periodontal therapy 12 months ago for Stage III Grade B periodontitis. He is a former smoker, having quit 2 years ago, and has well-controlled Type 2 diabetes. Clinical examination reveals generalised probing depths of 3-4 mm, with bleeding on probing at 15% of sites. What is the most appropriate recall interval for his supportive periodontal therapy (SPT)?

3 months, due to his history of advanced disease and presence of risk factors. (Correct answer)
12 months, as the probing depths are generally stable.
6 months, as he is a former smoker with controlled diabetes.
9 months, as a step-down from the initial 3-monthly recall.

Correct answer: 3 months, due to his history of advanced disease and presence of risk factors.

Patients with a history of Stage III or IV periodontitis, especially with modifying factors like diabetes (even if controlled), require more frequent maintenance. The initial year post-therapy often involves a 3-month recall. Given his history of advanced disease and existing risk factors, a 3-monthly interval is crucial to monitor stability, prevent recurrence, and manage inflammation, as indicated by the 15% bleeding score. Extending the interval to 6 or 12 months would be inappropriate for this level of risk.

Question 10: A routine panoramic radiograph of a 50-year-old asymptomatic male reveals a well-defined, ovoid radiolucency with a sclerotic border, located entirely inferior to the mandibular canal, near the angle of the mandible. What is the most likely diagnosis?

Traumatic Bone Cyst
Residual Cyst
Odontogenic Keratocyst (OKC)
Stafne Defect (Static Bone Cavity) (Correct answer)

Correct answer: Stafne Defect (Static Bone Cavity)

A Stafne defect has a classic radiographic presentation: a well-defined, corticated radiolucency located below the inferior alveolar canal in the posterior mandible. It is an anatomical depression on the lingual surface of the mandible containing ectopic salivary gland tissue and is considered a developmental anomaly, not a true cyst. Its position inferior to the canal is a key diagnostic feature that helps differentiate it from odontogenic lesions.

Question 11: Condensation silicone impression materials are less dimensionally stable than addition silicones primarily because:

They have higher viscosity and trap more air
They absorb oral fluids during setting
They release ethanol as a by-product of the condensation polymerization reaction (Correct answer)
They require longer intraoral setting time

Correct answer: They release ethanol as a by-product of the condensation polymerization reaction

Condensation silicones polymerize via a reaction that releases low-molecular-weight ethanol, which evaporates from the set impression over time, causing shrinkage.

Question 12: Which property of dental amalgam describes its slow, permanent deformation under sustained compressive load?

Hardness
Compressive strength
Creep (Correct answer)
Tarnish resistance

Correct answer: Creep

Creep is the time-dependent plastic deformation of amalgam under sustained stress, which can lead to marginal failure if excessive.

Question 13: The freeway space (interocclusal rest space) is typically:

5–7 mm
8–10 mm
2–4 mm (Correct answer)
0–1 mm

Correct answer: 2–4 mm

The freeway space, the distance between the teeth at rest position and at maximum intercuspation, is typically 2–4 mm.

Question 14: Which factor is MOST important when determining the restorability of a tooth?

Patient preference
Tooth position in the arch
Patient age
Remaining tooth structure and crown-to-root ratio (Correct answer)

Correct answer: Remaining tooth structure and crown-to-root ratio

Remaining coronal tooth structure and an adequate crown-to-root ratio are the primary determinants of whether a tooth can be successfully restored.

Question 15: The most appropriate management for a tooth with a history of previous trauma that now exhibits apical resorption is:

extraction, apical resection, retro filling, and replantation.
complete instrumentation and medication with intra-canal calcium hydroxide. (Correct answer)
immediate instrumentation and obturation followed by apical curettage.
extraction and replacement with a fixed or removable prosthesis.
observation over 6 months for further resorption.

Correct answer: complete instrumentation and medication with intra-canal calcium hydroxide.

Explanation: This option is the most appropriate initial management for a tooth with apical resorption following trauma. Complete instrumentation involves cleaning and shaping the root canal system to remove any necrotic or infected tissue. Medication with intracanal calcium hydroxide helps disinfect the canal and promote healing. Calcium hydroxide has antimicrobial properties and can also induce hard-tissue formation, aiding in the repair of apical resorption.

Question 16: A patient with a multi-rooted molar exhibits a Class II furcation involvement. The area is difficult for the patient to clean, and there is persistent inflammation despite excellent overall oral hygiene and regular non-surgical debridement. Which of the following surgical interventions would be most appropriate to improve cleansibility and manage the defect?

Free gingival graft.
Tunnel preparation. (Correct answer)
Root amputation of one of the roots.
Gingivectomy.

Correct answer: Tunnel preparation.

Tunnel preparation is a surgical procedure specifically designed for mandibular molars with Class II or III furcation involvement where there is sufficient root divergence. It involves removing interradicular bone to create a space that is patent and cleansable with interdental aids like a proxy brush. This approach makes the previously inaccessible furcation area accessible for patient maintenance. Root amputation might be considered, but tunnel preparation specifically addresses cleansibility of the existing structure. A gingivectomy or free gingival graft would not address the bone defect within the furcation.

Question 17: What does a positive response to percussion test most commonly indicate?

Healthy periodontium
Periapical inflammation or periodontitis (Correct answer)
Vital pulp with no inflammation
Presence of internal resorption

Correct answer: Periapical inflammation or periodontitis

Pain on percussion indicates inflammation in the periapical tissues or periodontal ligament surrounding the tooth.

Question 18: Which of the following is the primary objective of using formocresol as a medicament during a pulpotomy procedure on a primary tooth?

To completely disinfect and sterilise the entire root canal system.
To stimulate the formation of a reparative dentine bridge.
To mummify and fix the radicular pulp tissue, rendering it inert. (Correct answer)
To promote revascularisation of the coronal pulp tissue.

Correct answer: To mummify and fix the radicular pulp tissue, rendering it inert.

Formocresol is a fixative agent. Its primary objective in a pulpotomy is to fix (mummify) the remaining vital radicular pulp tissue, rendering it inert and resistant to bacterial breakdown. It does not stimulate a dentine bridge (like calcium hydroxide or MTA might), nor does it fully sterilise the entire canal system or promote revascularisation. It essentially preserves the radicular pulp in a fixed state until the tooth exfoliates naturally.

Question 19: Case Scenario: A patient reports a clicking sound and discomfort while opening their mouth. What is the most likely cause of this symptom?

Periodontal disease
Dental caries
Bruxism
Temporomandibular joint (TMJ) disorder (Correct answer)

Correct answer: Temporomandibular joint (TMJ) disorder

Explanation: Clicking sounds and discomfort while opening the mouth are common symptoms of temporomandibular joint (TMJ) disorders, which affect the jaw joint and surrounding muscles.

Question 20: Which of the following provides the highest level of assurance that a sterilisation cycle in a steam autoclave has been effective in killing all microbial life, including highly resistant spores?

A Class 5 chemical integrating indicator inside the package changing colour as specified.
A Class 1 chemical indicator on the outside of a package changing colour.
The autoclave's physical printout showing the correct time, temperature, and pressure were reached.
A biological indicator (spore test) showing no growth after incubation. (Correct answer)

Correct answer: A biological indicator (spore test) showing no growth after incubation.

Biological indicators (BIs), which contain highly resistant bacterial spores (e.g., Geobacillus stearothermophilus), are the gold standard for verifying sterilisation. A successful cycle will kill these spores, and subsequent incubation will show no growth, providing direct proof of the steriliser's sporicidal efficacy. Physical and chemical indicators monitor the conditions but do not directly prove that microorganisms have been killed.

Question 21: Which developmental groove on the mandibular first molar separates the mesiobuccal and distobuccal cusps?

Lingual groove
Central groove
Buccal groove (Correct answer)
Distal groove

Correct answer: Buccal groove

The buccal groove of the mandibular first molar separates the mesiobuccal and distobuccal cusps on the buccal surface.

Question 22: Among commonly used luting cements, which has the highest compressive strength?

Zinc phosphate cement (Correct answer)
Zinc oxide eugenol cement
Polycarboxylate cement
Conventional glass ionomer cement

Correct answer: Zinc phosphate cement

Zinc phosphate cement has the highest compressive strength (~100 MPa) of the classical luting cements, making it suitable for high-stress applications despite its lack of adhesion.

Question 23: Root canal therapy may be safely and successfully undertaken for: 1. hemophiliacs. 2. patients with a history of rheumatic fever. 3. patients with rheumatoid arthritis. 4. cerebral palsy patients. 5. adolescent diabetics.

All of the above
2,3,4
1,2,3,5 (Correct answer)
2,3,5

Correct answer: 1,2,3,5

Explanation: The statement "Root canal therapy may be safely and successfully undertaken for (1) hemophiliacs, (2) patients with a history of rheumatic fever, (3) patients with rheumatoid arthritis, and (5) adolescent diabetics" is correct.

Question 24: Centric relation is best described as:

The musculoskeletally stable position of the condyle in the glenoid fossa (Correct answer)
The rest position of the mandible
Maximum intercuspation of teeth
The most retruded position of the mandible with teeth in contact

Correct answer: The musculoskeletally stable position of the condyle in the glenoid fossa

Centric relation is the musculoskeletally stable position of the condyle-disc assembly seated in the most superior-anterior position in the glenoid fossa.

Question 25: Case Scenario: A patient presents with malalignment of the upper and lower teeth, causing difficulty in chewing and speech. What is the most appropriate treatment option?

Administration of pain medication
Referral to an orthodontist for braces (Correct answer)
Extraction of the affected teeth
Placement of dental crowns

Correct answer: Referral to an orthodontist for braces

Explanation: Malalignment of teeth, also known as malocclusion, is best managed by an orthodontist who can assess the patient's bite and provide appropriate treatment such as braces.

Question 26: Which of the following is the primary function of a major connector in a mandibular removable partial denture?

To provide vertical support against occlusal forces.
To unite all components and distribute forces across the arch. (Correct answer)
To provide direct retention for the prosthesis.
To prevent horizontal movement of the abutment teeth.

Correct answer: To unite all components and distribute forces across the arch.

The primary function of a major connector (e.g., lingual bar or plate) is to provide rigidity and unite all other components of the RPD on one side of the arch with those on the other. This unification allows for the effective distribution of functional stresses to the supporting teeth and tissues, providing cross-arch stability and preventing the overloading of any single area.

Question 27: A patient presents with a radiolucency at the apex of a non-vital tooth with no swelling. What is the most likely diagnosis?

Lateral periodontal cyst
Dentigerous cyst
Periapical granuloma or cyst (Correct answer)
Periapical abscess

Correct answer: Periapical granuloma or cyst

A well-defined periapical radiolucency on a non-vital tooth without acute symptoms most commonly represents a periapical granuloma or radicular cyst.

Question 28: According to the Australian Dental Association's guidelines, what is the recommended routine practice for managing dental unit waterlines (DUWLs) to minimise biofilm contamination?

Relying on the mains water supply as it meets national drinking water standards.
Flushing waterlines for 2 minutes at the start of the day and for 20-30 seconds between patients. (Correct answer)
Performing a 'shock' disinfection treatment of the lines annually.
Using sterile water for all non-surgical procedures.

Correct answer: Flushing waterlines for 2 minutes at the start of the day and for 20-30 seconds between patients.

Standard Australian guidelines recommend a routine flushing protocol to reduce the microbial load from biofilm that accumulates overnight and between patients. This involves a longer flush to clear stagnant water at the start of the day and a shorter flush to clear patient material between appointments. While other methods like chemical treatments are also used, this flushing routine is a fundamental daily practice.

Question 29: What is the most appropriate first step when a patient presents with acute irreversible pulpitis causing severe spontaneous pain?

Perform pulpectomy or extraction to relieve the pain (Correct answer)
Prescribe analgesics and review in 1 week
Take a full-mouth radiograph series
Place a sedative dressing and monitor

Correct answer: Perform pulpectomy or extraction to relieve the pain

Acute irreversible pulpitis requires removal of the inflamed pulp tissue (pulpectomy or extraction) to provide definitive pain relief.

Question 30: A dental assistant sustains a superficial puncture wound from a contaminated explorer during instrument reprocessing. The patient source is unknown. After performing immediate first aid by washing the area with soap and water, what is the most critical next step according to Australian workplace safety protocols?

Immediately report the incident to the supervising dentist for risk assessment and documentation. (Correct answer)
Wait until the end of the day to see if any local signs of infection appear.
Request a precautionary course of broad-spectrum antibiotics from a GP.
Apply a strong antiseptic like iodine and cover the wound.

Correct answer: Immediately report the incident to the supervising dentist for risk assessment and documentation.

Australian guidelines emphasise the immediate reporting of any sharps or exposure incident to a supervisor. This allows for a prompt risk assessment, documentation, and determination of the need for further medical evaluation or post-exposure prophylaxis (PEP), which is crucial for managing potential transmission of blood-borne viruses.

Question 31: Which cusp of the maxillary first molar is known as the 'cusp of Carabelli'?

Mesiobuccal cusp
Distobuccal cusp
Distolingual cusp
Mesiolingual cusp — an additional tubercle on its lingual surface (Correct answer)

Correct answer: Mesiolingual cusp — an additional tubercle on its lingual surface

The cusp of Carabelli is a supplemental cusp or tubercle found on the mesiolingual cusp of the maxillary first molar.

Question 32: A 70-year-old female patient, who has been receiving intravenous zoledronic acid for bone metastases from breast cancer for the past three years, requires extraction of a non-restorable mandibular molar. According to Australian guidelines and best practice, which of the following is the most significant oral complication this patient is at high risk of developing?

Post-operative cellulitis
Excessive post-operative haemorrhage
Alveolar osteitis (dry socket)
Medication-Related Osteonecrosis of the Jaw (MRONJ) (Correct answer)

Correct answer: Medication-Related Osteonecrosis of the Jaw (MRONJ)

The patient is taking a potent intravenous bisphosphonate (zoledronic acid) for a malignancy indication and has been on the therapy for over two years. This places her in a high-risk category for developing Medication-Related Osteonecrosis of the Jaw (MRONJ). Dentoalveolar surgery, such as an extraction, is a major precipitating factor for MRONJ. While the other options are general risks of extraction, MRONJ is the specific, severe complication directly related to her systemic medication and is the primary concern.

Question 33: For an avulsed, fully developed permanent tooth that has been re-implanted, a favourable prognosis is most affected by the:

length of time the tooth has been out of the mouth. (Correct answer)
thoroughness of the curettage of the root surface.
rigidness of the splint.
effectiveness of the irrigation of the socket.
use of an appropriate antibiotic.

Correct answer: length of time the tooth has been out of the mouth.

Explanation: The prognosis of an avulsed permanent tooth that has been reimplanted is significantly influenced by the length of time the tooth remains out of the mouth before reimplantation. The sooner the tooth is reimplanted, the better the chances of success. Ideally, reimplantation should occur within 30 minutes to one hour after the avulsion to maximize the chances of successful reattachment and long-term survival. Delayed reimplantation significantly reduces the likelihood of a favorable outcome due to increased risk of root resorption, pulp necrosis, and ankylosis.

Question 34: The principal clinical advantage of resin-modified glass ionomer cement over conventional glass ionomer cement is:

Reduced sensitivity to early moisture contamination and improved early physical properties (Correct answer)
Greater total fluoride release over time
Significantly lower cost of the material
Superior biocompatibility with pulp tissue

Correct answer: Reduced sensitivity to early moisture contamination and improved early physical properties

The light-cured resin component in resin-modified GIC allows immediate polymerization, greatly reducing the early moisture sensitivity and improving initial strength compared to conventional GIC.

Question 35: Delayed expansion in zinc-containing amalgam is primarily caused by:

Over-trituration of the alloy
Contamination of the mix with moisture during condensation (Correct answer)
High mercury-to-alloy ratio
Under-trituration of the alloy

Correct answer: Contamination of the mix with moisture during condensation

Moisture contamination of zinc-containing amalgam causes a delayed expansion reaction due to hydrogen gas production, which can lead to postoperative pain and restoration failure.

Question 36: A 10-year-old child presents to your clinic 45 minutes after avulsing their maxillary central incisor (tooth 11) during a sports accident. The tooth has been kept in a dry handkerchief. The child is medically fit. What is the most appropriate immediate management step?

Scrub the root surface to remove debris, soak in doxycycline, and then replant.
Gently rinse the tooth with saline, replant it immediately, and splint for 2 weeks. (Correct answer)
Delay replantation and schedule an appointment with an endodontist for the next day.
Initiate root canal treatment on the tooth extra-orally before replanting.

Correct answer: Gently rinse the tooth with saline, replant it immediately, and splint for 2 weeks.

According to the International Association of Dental Traumatology (IADT) guidelines, for an avulsed permanent tooth with an open or closed apex and an extra-oral dry time of less than 60 minutes, the tooth should be gently rinsed with a sterile solution like saline, replanted as soon as possible, and a flexible splint placed for up to 2 weeks. Scrubbing the root surface is contraindicated as it damages the periodontal ligament cells. Delaying replantation significantly worsens the prognosis. Extra-oral RCT is only considered if the extra-oral dry time is prolonged ( > 60 mins).

Question 37: Which of the following is a significant advantage of using bioceramic sealers (e.g., MTA-based sealers) for root canal obturation compared to traditional zinc oxide-eugenol (ZOE) based sealers?

They exhibit significant shrinkage upon setting.
They are easier to remove for retreatment.
They are bioactive and promote hard tissue formation. (Correct answer)
They are hydrophobic and repel moisture.

Correct answer: They are bioactive and promote hard tissue formation.

Bioceramic sealers are known for their biocompatibility and bioactivity. They can interact with periradicular tissues to promote the formation of cementum and bone, which is advantageous for healing. Unlike ZOE sealers, they are hydrophilic (set in the presence of moisture) and undergo slight expansion upon setting. A major disadvantage is that they are very difficult to remove, making retreatment challenging.

Question 38: What is the FIRST step when a new patient presents for a comprehensive dental examination?

Taking radiographs
Charting existing restorations
Recording a detailed medical and dental history (Correct answer)
Performing periodontal probing

Correct answer: Recording a detailed medical and dental history

Recording a thorough medical and dental history is the first and most critical step in any comprehensive examination, as it identifies systemic conditions and risk factors that affect treatment planning.

Question 39: A dentist in Australia is selecting a new composite resin for posterior restorations. To ensure the material is approved for use, which regulatory body's approval is essential?

The Australian Dental Association (ADA)
The Food and Drug Administration (FDA)
The National Health and Medical Research Council (NHMRC)
The Therapeutic Goods Administration (TGA) (Correct answer)

Correct answer: The Therapeutic Goods Administration (TGA)

In Australia, all medical devices, including dental restorative materials, are regulated by the Therapeutic Goods Administration (TGA). The TGA's role is to safeguard public health and safety by ensuring that medical devices supplied in Australia meet stringent standards of safety, quality, and performance. A material must be listed on the Australian Register of Therapeutic Goods (ARTG) before it can be legally supplied and used.

Question 40: The most appropriate management for at tooth with a history of previous trauma that now exhibits apical resorption is:

extraction, apical resection, retrofilling, and replantation.
complete instrumentation and medication with intra-canal calcium hydroxide. (Correct answer)
extraction and replacement with a fixed or removable prosthesis.
immediate instrumentation and obturation followed by apical curettage.
observation over 6 months for further resorption.

Correct answer: complete instrumentation and medication with intra-canal calcium hydroxide.

Explanation: This option is the most appropriate management for a tooth with apical resorption following trauma. Complete instrumentation involves cleaning and shaping the root canal system to remove any necrotic or infected tissue. Medication with intracanal calcium hydroxide helps disinfect the canal and promote healing. Calcium hydroxide has antimicrobial properties and can also induce hard-tissue formation, aiding in the repair of apical resorption.

Question 41: When is an immediate denture most indicated?

When anterior teeth are being extracted and the patient cannot be without teeth during healing (Correct answer)
When the patient has no remaining natural teeth
When posterior teeth only are being removed
When a patient refuses tooth extraction

Correct answer: When anterior teeth are being extracted and the patient cannot be without teeth during healing

An immediate denture is fabricated before extraction and inserted at the time of anterior tooth removal so the patient is not edentulous during healing.

Question 42: A 55-year-old patient requires a full coverage crown for tooth 25, which has had root canal treatment and a large MOD amalgam restoration. Clinical examination reveals 1.5mm of sound coronal tooth structure above the gingival margin circumferentially. What is the most critical factor for the long-term fracture resistance of the final restoration?

Achieving an adequate ferrule effect. (Correct answer)
The choice of post and core material.
The type of luting cement used.
The occlusal anatomy of the crown.

Correct answer: Achieving an adequate ferrule effect.

The ferrule effect, which is the 360-degree collar of a crown encircling the parallel walls of sound dentine, is crucial for protecting a root-treated tooth from fracture. A minimum of 1.5-2mm of ferrule height is widely recommended to provide a bracing action that resists functional lever forces and dissipates occlusal stresses. While other factors like cement and post material are important, the ferrule is considered the most critical structural feature for improving fracture resistance and long-term prognosis.

Question 43: In Angle's Class II malocclusion, the mesiobuccal cusp of the maxillary first molar occludes:

In the buccal groove of the mandibular first molar
Mesial to the buccal groove of the mandibular first molar (Correct answer)
Distal to the buccal groove of the mandibular first molar
In the embrasure between the mandibular first and second molars

Correct answer: Mesial to the buccal groove of the mandibular first molar

In Class II malocclusion, the mandibular arch is positioned distally, so the mesiobuccal cusp of the upper first molar occludes mesial to the buccal groove of the lower first molar.

Question 44: A 72-year-old patient received new complete maxillary and mandibular dentures one week ago. They return complaining that the lower denture lifts every time they move their tongue. Which of the following is the most likely cause?

The mandibular lingual flanges are overextended. (Correct answer)
The posterior palatal seal of the maxillary denture is inadequate.
The denture teeth are set too far buccally.
The occlusal vertical dimension is too high.

Correct answer: The mandibular lingual flanges are overextended.

Overextension of the lingual flanges of a mandibular complete denture will impinge on the mylohyoid muscle and the floor of the mouth. When the patient lifts or moves their tongue, these muscles contract and dislodge the denture. An inadequate posterior palatal seal affects the maxillary denture, and incorrect vertical dimension or tooth position typically causes different issues like muscle fatigue or cheek biting.

Question 45: Which index is used to assess the severity of periodontal disease in the ADC examination context?

Basic Periodontal Examination (BPE) (Correct answer)
CPITN score
OHI-S index
DMFT index

Correct answer: Basic Periodontal Examination (BPE)

The Basic Periodontal Examination (BPE) uses a WHO probe to screen and record periodontal status using codes 0–4 plus an asterisk.

Question 46: A 2-year-old presents with a fracture of the incisal third of tooth 21. exposing a small amount of dentin. The fracture occurred one hour previously. There is no mobility of the tooth but the patient complains that it is rough and sensitive to cold. The most appropriate emergency treatment is to:

smooth the surrounding enamel and apply glass ionomer cement. (Correct answer)
place a provisional (temporary) crown.
open the pulp chamber, clean the canal, and temporarily close it with zinc oxide and eugenol.
smooth the surrounding enamel and apply a calcium hydroxide cement.

Correct answer: smooth the surrounding enamel and apply glass ionomer cement.

Explanation: Overall, applying glass ionomer cement after smoothing the enamel provides immediate protection to the exposed dentin, reduces sensitivity to cold stimuli, and helps to prevent further complications while the patient awaits definitive treatment. This approach is less invasive than opening the pulp chamber and cleaning the canal, which may not be necessary as an initial emergency measure in a tooth with no signs of pulp exposure or mobility.

Question 47: A patient taking Warfarin for atrial fibrillation requires an extraction. Which analgesic, if prescribed for post-operative pain, would most significantly increase the risk of bleeding by potentiating the effect of Warfarin?

Codeine
Tramadol
Paracetamol
Ibuprofen (Correct answer)

Correct answer: Ibuprofen

Non-steroidal anti-inflammatory drugs (NSAIDs) like Ibuprofen significantly increase the anticoagulant effect of Warfarin and the risk of bleeding. This occurs through multiple mechanisms, including inhibition of platelet function and displacement of warfarin from plasma protein binding sites, which increases the concentration of free, active drug. Paracetamol and opioids are considered safer alternatives in patients taking Warfarin.

Question 48: A patient reports taking warfarin. What is the most appropriate pre-operative action before performing a surgical extraction?

Prescribe aspirin as a substitute anticoagulant
Check the INR and consult with the patient's physician (Correct answer)
Discontinue warfarin 7 days before surgery
Proceed without any modification as dental extractions are minor

Correct answer: Check the INR and consult with the patient's physician

The INR (International Normalized Ratio) must be checked and the prescribing physician consulted to determine a safe INR level for the planned procedure.

Question 49: Which test is most appropriate to determine pulp vitality in a tooth with a full-coverage crown?

Electric pulp test (Correct answer)
Hot test (gutta-percha)
Cold test (ethyl chloride)
Percussion test

Correct answer: Electric pulp test

The electric pulp test is preferred for crowned teeth because it delivers a standardized stimulus through the crown where thermal tests may give unreliable readings.

Question 50: A patient has uncontrolled type 2 diabetes with an HbA1c of 11%. What is the most appropriate approach for elective dental surgery?

Perform surgery under general anesthesia only
Proceed immediately as dental infections worsen glycemic control
Defer elective surgery and refer to the patient's physician for better glycemic control (Correct answer)
Prescribe a double antibiotic prophylaxis dose and proceed

Correct answer: Defer elective surgery and refer to the patient's physician for better glycemic control

Elective surgery should be deferred for patients with poorly controlled diabetes (HbA1c >8%) because of increased infection risk and impaired wound healing; referral for medical management is indicated.

Question 51: The Curve of Wilson refers to:

The arc of closure of the mandible
The sagittal curvature of the posterior occlusal plane
The curvature of the mandibular incisors
The mediolateral curvature passing through the buccal and lingual cusp tips of opposing molars (Correct answer)

Correct answer: The mediolateral curvature passing through the buccal and lingual cusp tips of opposing molars

The Curve of Wilson is the mediolateral (transverse) curvature that passes through the buccal and lingual cusp tips of opposing molar teeth.

Question 52: A periapical radiograph of a mandibular incisor shows a diffuse, ill-defined radiolucency at the apex with a loss of the lamina dura. The patient is systemically unwell with a fever and reports severe, spontaneous pain. The tooth is non-vital and extremely tender to percussion. What is the most likely radiographic diagnosis?

Acute Periapical Abscess (Correct answer)
Chronic Periapical Periodontitis (Granuloma)
Radicular Cyst
Condensing Osteitis

Correct answer: Acute Periapical Abscess

An acute periapical abscess is a rapid-onset infection often accompanied by systemic symptoms. Radiographically, early or acute lesions are characterized by a widening of the PDL space and a diffuse, poorly defined radiolucency as the infection spreads through the cancellous bone without a well-established border. This contrasts with chronic granulomas and cysts, which are slow-growing and typically appear as well-circumscribed radiolucencies. Condensing osteitis is a radiopaque lesion.

Question 53: A 45-year-old patient with severe dental anxiety and no other medical conditions is scheduled for a lengthy procedure under oral sedation using Diazepam. Which piece of pre-operative advice is most critical for ensuring patient safety?

Arrange for an escort to drive them home from the appointment. (Correct answer)
Take the medication with a large meal to avoid nausea.
Double the dose if they still feel anxious one hour before.
Avoid caffeine for at least 24 hours prior to the appointment.

Correct answer: Arrange for an escort to drive them home from the appointment.

Diazepam is a benzodiazepine that causes central nervous system depression, leading to drowsiness, impaired coordination, and altered judgement. These effects make it unsafe to drive or operate machinery. For safety, it is mandatory for a patient who has taken an oral sedative to be accompanied by a responsible adult escort to and from the appointment.

Question 54: In the context of Angle's classification of malocclusion, which of the following accurately describes a Class III relationship?

The distobuccal cusp of the maxillary first molar occludes in the buccal groove of the mandibular first molar.
The mesiobuccal cusp of the maxillary first molar occludes distal to the buccal groove of the mandibular first molar. (Correct answer)
The mesiobuccal cusp of the maxillary first molar occludes in the buccal groove of the mandibular first molar.
The mesiobuccal cusp of the maxillary first molar occludes mesial to the buccal groove of the mandibular first molar.

Correct answer: The mesiobuccal cusp of the maxillary first molar occludes distal to the buccal groove of the mandibular first molar.

Angle's Class III malocclusion is defined by the mesiobuccal cusp of the maxillary first permanent molar occluding distal to the buccal groove of the mandibular first permanent molar. This relationship often results in an anterior crossbite or 'underbite' appearance. Class I is when the cusp occludes with the groove, and Class II is when the cusp occludes mesial to the groove.

Question 55: Which of the following radiographic features is most suggestive of a benign lesion rather than a malignant one?

Ill-defined or ragged borders
A well-defined, corticated margin (Correct answer)
Evidence of cortical bone destruction and invasion into soft tissue
A 'moth-eaten' or permeative appearance of bone

Correct answer: A well-defined, corticated margin

Benign, slow-growing lesions typically displace surrounding structures rather than invading them, allowing the body to form a reactive, dense bony border (cortex or sclerosis) around the lesion. This appears as a clear, well-defined white line on a radiograph. Malignant lesions grow rapidly and infiltrate tissue, resulting in ill-defined, invasive borders, a 'moth-eaten' appearance, and destruction of the cortex.

Question 56: Irreversible hydrocolloid (alginate) impression material is classified as:

An elastic material that sets via irreversible chemical reaction and cannot be reused (Correct answer)
An elastomeric addition-polymerization material
A rigid non-elastic impression material
A thermoplastic, non-elastic material

Correct answer: An elastic material that sets via irreversible chemical reaction and cannot be reused

Alginate is an elastic hydrocolloid that undergoes an irreversible chemical crosslinking reaction, so it cannot be remelted or reused unlike reversible hydrocolloid.

Question 57: How many lobes does the maxillary central incisor develop from?

5
2
3
4 (Correct answer)

Correct answer: 4

The maxillary central incisor develops from 4 developmental lobes: 3 labial lobes (forming the mamelons) and 1 lingual lobe (forming the cingulum).

Question 58: The working time of zinc phosphate cement can be extended by:

Warming the mixing slab
Incorporating all powder at once
Using a higher powder-to-liquid ratio
Spatulating on a cooled glass slab and adding powder incrementally (Correct answer)

Correct answer: Spatulating on a cooled glass slab and adding powder incrementally

Cooling the glass slab slows the exothermic setting reaction, and incremental powder addition controls the rate of pH rise, together extending the working time to 3–6 minutes.

Question 59: The solidus temperature of a casting alloy is defined as the temperature at which:

The alloy is completely solidified on cooling (Correct answer)
The alloy first begins to melt on heating
The alloy should be poured into the mold
The alloy undergoes annealing

Correct answer: The alloy is completely solidified on cooling

The solidus temperature is the highest temperature at which the alloy is entirely in the solid state; below this temperature, no liquid phase exists.

Question 60: According to current Australian guidelines for infective endocarditis prophylaxis, which of the following patient conditions requires antibiotic cover prior to an invasive dental procedure such as an extraction?

Mitral valve prolapse with regurgitation
Prosthetic heart valve (Correct answer)
Previous coronary artery bypass surgery
Bicuspid aortic valve

Correct answer: Prosthetic heart valve

Current Australian guidelines restrict antibiotic prophylaxis to patients with the highest risk of adverse outcomes from infective endocarditis. This group includes patients with a prosthetic heart valve or material used for valve repair, a history of previous infective endocarditis, and certain congenital heart conditions. Conditions such as mitral valve prolapse, previous bypass surgery, and bicuspid aortic valve are no longer considered indications for routine antibiotic prophylaxis.

Question 61: Which of the following is NOT a characteristic of dental amalgam?

It is a durable restorative material.
It is tooth-colored and aesthetic. (Correct answer)
It contains mercury as one of its components.
It requires minimal tooth preparation.

Correct answer: It is tooth-colored and aesthetic.

Explanation: Dental amalgam is a silver-colored filling material composed of various metals, including mercury, silver, tin, and copper. It is not tooth-colored and is not considered aesthetically pleasing.

Question 62: In endodontics, which of the following perforations has the poorest prognosis?

Near the apex.
Furcation area of a molar. (Correct answer)
Coronal to the epithelial attachment.
Apical to the epithelial attachment.

Correct answer: Furcation area of a molar.

Explanation: Perforations of molar furcation, particularly in endodontics, are associated with the poorest prognosis for several reasons: Difficulty in Access and Instrumentation Limited Healing Potential Increased Risk of Reinfection Inadequate Seal and Restoration Periodontal Involvement

Question 63: How many cusps does a maxillary first molar typically have?

5
4 (Correct answer)
6
3

Correct answer: 4

The maxillary first molar typically has 4 major cusps: mesiobuccal, distobuccal, mesiolingual, and distolingual.

Question 64: Which investigation is most appropriate when suspecting a salivary gland obstruction by a calculus?

Occlusal radiograph
Panoramic radiograph
CBCT
Ultrasound or sialography (Correct answer)

Correct answer: Ultrasound or sialography

Ultrasound or sialography is the preferred investigation for salivary gland ductal obstruction as they can visualise the gland, duct, and any calculi or strictures.

Question 65: When treating a patient with a history of bisphosphonate use, which complication is of greatest concern following tooth extraction?

Accelerated bone healing
Increased risk of post-extraction dry socket
Increased post-operative bleeding
Medication-related osteonecrosis of the jaw (MRONJ) (Correct answer)

Correct answer: Medication-related osteonecrosis of the jaw (MRONJ)

Bisphosphonates inhibit osteoclast activity and can impair bone remodeling, leading to medication-related osteonecrosis of the jaw (MRONJ) following dento-alveolar surgery.

Question 66: Which nerve block is most appropriate to anesthetize the mandibular molars for restorative work?

Inferior alveolar nerve block (IANB) (Correct answer)
Incisive nerve block
Mental nerve block
Long buccal nerve block

Correct answer: Inferior alveolar nerve block (IANB)

The inferior alveolar nerve block (IANB) is the standard injection to anesthetize the inferior alveolar nerve, providing pulpal anesthesia to all mandibular teeth on that side.

Question 67: What is the purpose of a study cast (diagnostic model) in treatment planning?

To determine the correct shade for ceramic restorations
To fabricate temporary restorations chairside
To provide a three-dimensional record of the patient's dentition for diagnosis and planning (Correct answer)
To check the patient's gingival health over time

Correct answer: To provide a three-dimensional record of the patient's dentition for diagnosis and planning

Study casts provide a three-dimensional, permanent record of the patient's occlusion and arch form, enabling detailed diagnosis and treatment planning outside the clinical environment.

Question 68: In the context of developing oral squamous cell carcinoma (OSCC), what is the significance of a patient's combined heavy smoking and alcohol consumption habits?

Alcohol is the primary carcinogen, and tobacco is a minor promoter.
They have a synergistic effect, significantly increasing the risk more than the sum of their individual effects. (Correct answer)
Tobacco is the primary carcinogen, and alcohol has no proven effect on risk.
They are independent risk factors with no interactive effect.

Correct answer: They have a synergistic effect, significantly increasing the risk more than the sum of their individual effects.

Tobacco and alcohol are the two most significant risk factors for OSCC. Their combined use has a synergistic effect, meaning the total risk is much greater (up to 30-fold) than the additive risk of using either substance alone. Alcohol is thought to act as a solvent, increasing the permeability of the oral mucosa to the carcinogens found in tobacco smoke.

Question 69: What is the primary reason for recording a comprehensive medical history before dental treatment?

To determine the patient's payment method
Legal documentation purposes only
To identify conditions and medications that may affect treatment safety and outcomes (Correct answer)
To comply with insurance requirements

Correct answer: To identify conditions and medications that may affect treatment safety and outcomes

A comprehensive medical history identifies systemic conditions, medications, and allergies that can directly affect the safety and planning of dental treatment.

Question 70: Type III dental stone (improved stone) differs from Type II dental plaster in that it has:

A higher water-to-powder ratio and lower compressive strength
Greater setting expansion and more porosity
A faster setting time due to added accelerators
A lower water-to-powder ratio and higher compressive strength (Correct answer)

Correct answer: A lower water-to-powder ratio and higher compressive strength

Type III stone (hemihydrate crystals are more regular in shape) requires less mixing water, producing a denser, stronger set product with compressive strength ~35 MPa compared to ~12 MPa for plaster.

Question 71: Which clinical sign indicates inadequate ferrule effect when planning a crown for an endodontically treated tooth?

Presence of a post and core
Less than 2 mm of sound tooth structure above the crestal bone (Correct answer)
Tooth with two canals
Root length greater than 14 mm

Correct answer: Less than 2 mm of sound tooth structure above the crestal bone

A ferrule requires at least 2 mm of sound, parallel dentinal walls above the finish line; less than this compromises crown retention and fracture resistance.

Question 72: A 48-year-old female patient presents with asymptomatic, bilateral, white, lace-like lesions on her buccal mucosa. She has no other medical history of note. The lesions do not rub off on examination. What is the most likely diagnosis?

Oral Candidiasis
Leukoplakia
Linea Alba
Reticular Oral Lichen Planus (Correct answer)

Correct answer: Reticular Oral Lichen Planus

The description of bilateral, asymptomatic, white, lace-like (reticular) striae on the buccal mucosa is the classic presentation of reticular oral lichen planus. Oral candidiasis typically presents as white plaques that can be wiped off, often leaving an erythematous base. Leukoplakia is a clinical term for a white patch that is not attributable to another disease and is typically unilateral. Linea alba is a benign frictional keratosis that corresponds precisely to the occlusal plane.

Question 73: How many root canals does the maxillary first premolar most commonly have?

4
3
2 (Correct answer)
1

Correct answer: 2

The maxillary first premolar most commonly has 2 root canals, one buccal and one palatal.

Question 74: A dentist identifies a 1.5 cm, indurated, non-healing ulcer on the lateral border of the tongue of a 60-year-old male smoker. The lesion is suspicious for malignancy. Which of the following is the most appropriate diagnostic step?

Perform an incisional biopsy taking a wedge of tissue from the lesion's border. (Correct answer)
Perform an excisional biopsy to remove the entire lesion and a 2mm margin.
Review the patient in two weeks to see if the lesion has resolved on its own.
Use a cytological brush to scrape cells from the surface for analysis.

Correct answer: Perform an incisional biopsy taking a wedge of tissue from the lesion's border.

For a lesion that is clinically suspicious of malignancy or larger than 1cm, an incisional biopsy is the standard of care. This procedure provides a representative tissue sample to establish a definitive histopathological diagnosis before a definitive treatment plan (often involving wide excision and specialist care) is formulated. Excisional biopsy is typically reserved for smaller (<1cm) lesions that appear benign. Delaying diagnosis of a suspicious lesion is inappropriate.

Question 75: Case Scenario: A patient presents with pain and swelling in the lower right jaw. On examination, you notice a draining sinus tract near the mandibular molars. What is the most likely diagnosis?

Periapical abscess (Correct answer)
Mandibular fracture
Temporomandibular joint disorder (TMJ)
Periodontal abscess

Correct answer: Periapical abscess

Explanation: The presence of a draining sinus tract near the mandibular molars indicates an infection originating from the tooth's apex, known as a periapical abscess.

Question 76: Case Scenario: A patient complains of tooth sensitivity to colds and sweets. On examination, you notice a visible cavity in the tooth. What is the most appropriate initial treatment?

Prescribe antibiotics.
Apply a desensitizing agent.
Perform a tooth extraction.
Restore the tooth with a filling. (Correct answer)

Correct answer: Restore the tooth with a filling.

Explanation: The visible cavity indicates dental caries. The most appropriate initial treatment is to restore the tooth with a filling to prevent further decay and alleviate sensitivity.

Question 77: Which of the following statements best reflects the current evidence-based approach to managing an initial, non-cavitated carious lesion on the proximal surface of a posterior tooth in an adult patient with low caries risk in Australia?

Prescribing an antimicrobial mouthrinse to eliminate cariogenic bacteria.
Immediate operative intervention with a slot preparation and direct composite.
Application of a professionally applied high-concentration fluoride varnish and radiographic monitoring. (Correct answer)
Restoring the lesion with a preventative resin restoration (PRR).

Correct answer: Application of a professionally applied high-concentration fluoride varnish and radiographic monitoring.

Australian caries management protocols prioritize non-invasive strategies for initial lesions. For a non-cavitated lesion, the goal is to arrest and remineralize the tooth structure. This is best achieved through secondary prevention methods such as the professional application of fluoride varnish, coupled with dietary advice, oral hygiene instruction, and regular monitoring (e.g., with bitewing radiographs at appropriate intervals) to assess lesion activity. Operative treatment is reserved for cavitated lesions or lesions showing clear evidence of progression despite preventive efforts.

Question 78: A 7-year-old child in the mixed dentition stage presents with a unilateral posterior crossbite involving the permanent first molars. Upon closing, there is a clear functional mandibular shift towards the side of the crossbite. Which of the following is the most appropriate initial orthodontic intervention?

Maxillary expansion using an appliance like a Quad Helix or RPE. (Correct answer)
Fixed orthodontic appliances (full braces).
Observation until all permanent teeth have erupted.
Surgical-assisted rapid palatal expansion (SARPE).

Correct answer: Maxillary expansion using an appliance like a Quad Helix or RPE.

A unilateral posterior crossbite with a functional shift is indicative of a constricted maxillary arch. Early intervention in the mixed dentition is recommended to prevent asymmetrical mandibular growth and potential facial asymmetry. Maxillary expansion using an appliance such as a Quad Helix or a Rapid Palatal Expander (RPE) is the treatment of choice to correct the transverse discrepancy, which in turn eliminates the functional shift. Observation is inappropriate as the condition can worsen, and surgery (SARPE) is reserved for skeletally mature patients.

Question 79: A 68-year-old patient presents with significant cervical abrasion and dentine hypersensitivity on teeth 33, 34, and 35. The lesions are shallow but wide. Which restorative material would be most suitable for restoring these non-carious cervical lesions (NCCLs) considering both restorative and therapeutic benefits?

Resin-modified glass ionomer cement (RMGIC) for its adhesion and fluoride release. (Correct answer)
Dental amalgam for its proven longevity.
A full-coverage ceramic veneer for optimal aesthetics.
Micro-filled composite resin for superior polishability.

Correct answer: Resin-modified glass ionomer cement (RMGIC) for its adhesion and fluoride release.

Resin-modified glass ionomer cements (RMGICs) are often the material of choice for non-carious cervical lesions. They offer several key advantages in this clinical scenario: they chemically bond to dentin, which is beneficial in an area where enamel is absent; they have a degree of flexibility that can accommodate tooth flexure at the cervical margin; and they release fluoride, which can help manage dentine hypersensitivity and prevent root caries. Clinical trials have shown GICs to be a high-performing adhesive system for NCCLs.

Question 80: The working side condyle during lateral mandibular movement is called:

Balancing condyle
Protrusive condyle
Orbiting condyle
Rotating condyle (Correct answer)

Correct answer: Rotating condyle

The working side condyle rotates in place during lateral excursion and is sometimes called the rotating or ipsilateral condyle.

Question 81: In a comprehensive examination, what does the 'soft tissue examination' include?

Inspection of lips, cheeks, tongue, floor of mouth, palate, and oropharynx for lesions or abnormalities (Correct answer)
Assessment of tooth mobility and pocket depths only
Palpation of the temporomandibular joint only
Recording of missing teeth and existing restorations

Correct answer: Inspection of lips, cheeks, tongue, floor of mouth, palate, and oropharynx for lesions or abnormalities

A thorough intraoral soft tissue examination includes systematic inspection of all mucosal surfaces including lips, buccal mucosa, tongue, floor of mouth, hard and soft palate, and oropharynx to detect pathology.

Question 82: A 60-year-old patient with an implant-supported crown on tooth 46, placed 5 years ago, presents for a routine check-up. Probing around the implant reveals a 6mm pocket with bleeding on probing. What is the most crucial additional diagnostic information required to differentiate between peri-mucositis and peri-implantitis?

The presence of suppuration from the pocket.
Comparison with a baseline radiograph. (Correct answer)
The patient's reported level of discomfort.
The mobility of the implant-supported crown.

Correct answer: Comparison with a baseline radiograph.

The key feature that distinguishes peri-implantitis from peri-mucositis is radiographic evidence of progressive bone loss beyond initial remodelling. Peri-mucositis is inflammation confined to the soft tissues without bone loss. While bleeding on probing indicates inflammation (present in both) and suppuration is a strong sign of infection, the definitive diagnosis of peri-implantitis requires confirmation of bone loss by comparing current radiographs to baseline or previous radiographs.

Question 83: What does the term 'informed consent' require in Australian dental practice?

The patient is provided with sufficient information about the proposed treatment, risks, alternatives, and consequences of no treatment, to make a voluntary decision (Correct answer)
Consent from the patient's family member is acceptable for an adult patient
The patient simply signs a form before treatment begins
Consent is only required for surgical procedures

Correct answer: The patient is provided with sufficient information about the proposed treatment, risks, alternatives, and consequences of no treatment, to make a voluntary decision

Valid informed consent requires the patient to receive adequate information about the procedure, potential risks, alternatives, and outcomes of refusal, and to voluntarily agree without coercion.

Question 84: In a Class I occlusion, the mesiobuccal cusp of the maxillary first molar occludes:

Between the mandibular first and second molars
In the buccal groove of the mandibular first molar (Correct answer)
Distal to the buccal groove of the mandibular first molar
Mesial to the buccal groove of the mandibular first molar

Correct answer: In the buccal groove of the mandibular first molar

In Angle's Class I occlusion, the mesiobuccal cusp of the upper first molar occludes in the buccal groove of the lower first molar.

Question 85: In the ADC examination context, what is the recommended approach for a tooth with a periapical abscess in an otherwise healthy patient?

Immediate extraction in all cases
Prescribe antibiotics alone without any surgical intervention
Incision and drainage if fluctuant, with antibiotics only if systemic signs are present, followed by definitive treatment (Correct answer)
Leave untreated as periapical abscesses resolve spontaneously

Correct answer: Incision and drainage if fluctuant, with antibiotics only if systemic signs are present, followed by definitive treatment

Management involves local surgical drainage if fluctuant, with systemic antibiotics reserved for cases with spreading infection or systemic signs, followed by definitive root canal therapy or extraction.

Question 86: Case Scenario: A patient presents with a fractured incisor tooth due to trauma. Which of the following is the most appropriate immediate management?

Assess for pulpal involvement and initiate root canal treatment if necessary. (Correct answer)
Apply fluoride varnish and advise the patient to return in a week.
Administer antibiotics and schedule for extraction.
Refer the patient to an orthodontist.

Correct answer: Assess for pulpal involvement and initiate root canal treatment if necessary.

Explanation: Trauma to the tooth can lead to pulp exposure or injury. Assessing for pulpal involvement is crucial to determine if root canal treatment is needed to preserve the tooth.

Question 87: The Curve of Spee is a curvature observed in which plane?

Sagittal plane (Correct answer)
Horizontal plane
Transverse plane
Frontal plane

Correct answer: Sagittal plane

The Curve of Spee is an anteroposterior (sagittal) curvature of the occlusal plane following the buccal cusps of mandibular posterior teeth.

Question 88: What does the acronym 'SOAP' represent in clinical documentation?

Symptoms, Observations, Assessment, Plan
Subjective, Objective, Assessment, Plan (Correct answer)
Subjective, Outcome, Assessment, Prescription
Symptoms, Outcome, Analysis, Procedure

Correct answer: Subjective, Objective, Assessment, Plan

SOAP stands for Subjective (patient's complaint), Objective (clinical findings), Assessment (diagnosis), and Plan (treatment plan).

Question 89: Which of the following systemic conditions requires antibiotic prophylaxis before invasive dental procedures per current guidelines?

Patients with a previous healed myocardial infarction (>6 months ago)
Mild hypertension controlled with medication
Well-controlled type 2 diabetes
Patients with a prosthetic cardiac valve (Correct answer)

Correct answer: Patients with a prosthetic cardiac valve

Current guidelines (AHA/ADA) recommend antibiotic prophylaxis for patients with prosthetic cardiac valves before invasive dental procedures due to the risk of infective endocarditis.

Question 90: What is the Bennett movement in mandibular kinematics?

Lateral bodily shift of the mandible during lateral excursion (Correct answer)
Protrusive movement of the mandible
Rotational movement around the transverse hinge axis
Retrusive glide from rest to centric occlusion

Correct answer: Lateral bodily shift of the mandible during lateral excursion

The Bennett movement is the lateral bodily shift of the mandible toward the working side during lateral excursion.

Question 91: A 65-year-old patient presents with painful, desquamating gingivitis and several intact bullae on the soft palate. Gentle lateral pressure on the clinically unaffected gingiva results in the formation of a new blister. What is this clinical sign called, and with which group of conditions is it most strongly associated?

Auspitz's sign; Psoriasis
Nikolsky's sign; Autoimmune blistering diseases (Correct answer)
Darier's sign; Mastocytosis
Wickham's striae; Oral Lichen Planus

Correct answer: Nikolsky's sign; Autoimmune blistering diseases

Nikolsky's sign is the clinical phenomenon where the epithelium dislodges from the underlying tissue with slight rubbing or pressure. It is a characteristic finding in autoimmune blistering (vesiculobullous) diseases such as Pemphigus Vulgaris and Mucous Membrane Pemphigoid. Auspitz's sign relates to psoriasis, Wickham's striae are pathognomonic for lichen planus, and Darier's sign is associated with mastocytosis.

Question 92: A patient presents 3 days after the extraction of tooth 46 with severe, radiating pain and a foul taste. Clinical examination reveals an empty socket with exposed, sensitive bone. What is the primary goal in the management of this alveolar osteitis (dry socket)?

To place a bone graft into the socket to accelerate tissue regeneration.
To surgically debride the socket walls to induce fresh bleeding.
To provide symptomatic relief of pain while healing by secondary intention occurs. (Correct answer)
To prescribe a course of broad-spectrum systemic antibiotics.

Correct answer: To provide symptomatic relief of pain while healing by secondary intention occurs.

Alveolar osteitis (dry socket) is a localised inflammatory condition, not a true infection, caused by the premature loss of the blood clot. The primary goal of management is palliative care to relieve the patient's severe pain. This is achieved by gentle irrigation to clean the socket of debris and placing a sedative dressing (e.g., Alvogyl or zinc oxide-eugenol pack). Systemic antibiotics are not indicated unless there are signs of spreading infection.

Question 93: A 25-year-old patient presents with a severe, spontaneous, throbbing pain in the mandibular right first molar (tooth 46) that worsens when lying down. Clinical examination reveals a deep carious lesion. The tooth is tender to percussion, and pulp vitality testing with a cold stimulus elicits a sharp, lingering pain. A periapical radiograph shows a widened periodontal ligament space around the mesial root apex. What is the most likely diagnosis for the pulp and periapical tissues?

Reversible pulpitis with normal apical tissues
Acute apical abscess with pulp necrosis
Pulp necrosis with asymptomatic apical periodontitis
Irreversible pulpitis with symptomatic apical periodontitis (Correct answer)

Correct answer: Irreversible pulpitis with symptomatic apical periodontitis

The patient's symptoms of spontaneous, severe, and lingering pain are classic signs of irreversible pulpitis. The tenderness to percussion and radiographic evidence of a widened PDL indicate that the inflammation has extended into the periapical tissues, leading to symptomatic apical periodontitis. Reversible pulpitis would present with sharp, non-lingering pain to a stimulus. Pulp necrosis would not respond to cold testing, and an acute apical abscess would typically present with more pronounced swelling.

Question 94: Case Scenario: During a routine dental examination, you notice redness and swelling around the gum line of a patient's tooth. What is the most likely diagnosis?

Gingivitis (Correct answer)
Periodontitis
Dental caries
Abscess

Correct answer: Gingivitis

Explanation: Redness and swelling around the gum line are characteristic signs of gingivitis, which is inflammation of the gums. It is often caused by poor oral hygiene.

Question 95: Case scenario: Alexander, a 64-year-old patient who is receiving warfarin as part of the management of his atrial fibrillation tells you that one of his lower right back teeth was restored three years ago by a dentist who has since retired from your practice. The tooth is now occasionally sensitive to hot and cold. The clinical notes confirm the history and indicate that the tooth was restored using a resin composite material. You obtain the periapical radiograph. In addition to testing the pulp vitality with either a cold or an electric pulp tester, which of the following clinical tests or procedures would be the most appropriate to assist in making a diagnosis?

Orthopantomogram (OPG)
International normalized ratio (INR) test
Crack test
Percussion test (Correct answer)
Bite-wing radiograph

Correct answer: Percussion test

Explanation: The percussion test involves tapping the tooth to assess for tenderness or discomfort, which can indicate inflammation or infection in the surrounding tissues or the tooth itself. In Alexander's case, since the tooth is occasionally sensitive to hot and cold, performing a percussion test can help determine if there is any underlying issue such as periapical inflammation or pulpitis.

Question 96: Which of the '5 Moments for Hand Hygiene' specifically applies to the action of a dental practitioner cleaning their hands immediately before donning sterile gloves for a surgical extraction?

Moment 2: Before a clean or aseptic procedure. (Correct answer)
Moment 4: After touching a patient.
Moment 1: Before touching a patient.
Moment 3: After body fluid exposure risk.

Correct answer: Moment 2: Before a clean or aseptic procedure.

Moment 2, 'Before a clean or aseptic procedure', is performed to protect the patient from the transmission of harmful organisms into a sterile site or mucous membrane. Donning gloves for a surgical procedure is a classic example of this moment, as hand hygiene must be performed immediately before putting on the gloves to prevent contamination.

Question 97: A 62-year-old female patient complains of a persistent dry mouth and a 'gritty' sensation in her eyes for the past year. Clinical examination reveals a lobulated tongue with papillary atrophy and bilateral, firm, non-tender swelling of the parotid glands. She has a high caries rate despite good oral hygiene. Which systemic autoimmune condition is most likely responsible for these findings?

Rheumatoid Arthritis
Sarcoidosis
Systemic Lupus Erythematosus (SLE)
Sjögren's Syndrome (Correct answer)

Correct answer: Sjögren's Syndrome

The combination of xerostomia (dry mouth) and xerophthalmia (dry eyes), known as sicca syndrome, along with bilateral salivary gland enlargement, is the hallmark of Sjögren's Syndrome. The resulting severe hyposalivation also explains the high caries rate. While patients with SLE or Rheumatoid Arthritis can have secondary Sjögren's, the primary presentation described points directly to this diagnosis. Sarcoidosis can cause parotid swelling, but the prominent sicca symptoms are more characteristic of Sjögren's.

Question 98: Which statement is FALSE regarding the use of a barbed broach?

Removal of vital or non-vital pulp tissue.
Removal of food debris from the canal.
Removal of paper points and cotton pellets.
Removal of gutta-percha during non-surgical re-treatment. (Correct answer)

Correct answer: Removal of gutta-percha during non-surgical re-treatment.

Explanation: Barbed broaches are not typically used for the removal of gutta-percha during nonsurgical retreatment. Gutta-percha removal during retreatment typically involves the use of heat, solvents, rotary instruments, or specialized retreatment files designed for this purpose. Barbed broaches are not well-suited for removing gutta-percha due to their design, which can lead to potential complications such as instrument fracture or canal transportation.

Question 99: When a second canal is located in mandibular incisors, it is most frequently found:

distal to the main canal.
labial to the main canal.
lingual of the main canal. (Correct answer)
mesial of the main canal

Correct answer: lingual of the main canal.

Explanation: The frequent location of a second canal lingual to the main canal in mandibular incisors is influenced by embryological development, anatomical considerations, and the variability of the root canal system, underscoring the importance of thorough clinical assessment and treatment planning.

Question 100: During the extraction of a maxillary first molar (tooth 16), you suspect a small oroantral communication (OAC) of approximately 2mm has been created. There is no pre-existing sinus pathology. What is the most appropriate immediate management?

Prescribe a one-week course of antibiotics and nasal decongestants as the sole management.
Immediately refer the patient to an oral and maxillofacial surgeon for a buccal advancement flap.
Leave the socket open to drain and provide strict sinus precautions.
Promote and protect the blood clot with a haemostatic agent and a figure-of-eight suture. (Correct answer)

Correct answer: Promote and protect the blood clot with a haemostatic agent and a figure-of-eight suture.

For a small OAC (<2-3 mm) in a healthy sinus, the primary objective is to maintain a stable blood clot within the socket, which will allow for spontaneous healing. This is best achieved by placing a resorbable haemostatic agent (e.g., Gelfoam) and securing it with a suture (e.g., figure-of-eight) to provide a scaffold for the clot. While sinus precautions and medications are important adjuncts, the key immediate step is mechanical protection of the clot. Larger defects (>5mm) typically require surgical flap closure.

Question 101: When preparing a moderate-sized Class I cavity for a direct composite resin restoration on a mandibular molar, which of the following cavity design principles is most consistent with modern adhesive dentistry practices in Australia?

Creating convergent walls and a flat pulpal floor for macromechanical retention.
Placing retentive grooves in the dentin to prevent dislodgement of the restoration.
Extending the preparation to include all adjacent fissures for 'extension for prevention'.
Following the outline of the carious lesion, resulting in a conservative, 'scooped-out' preparation with rounded internal line angles. (Correct answer)

Correct answer: Following the outline of the carious lesion, resulting in a conservative, 'scooped-out' preparation with rounded internal line angles.

Modern adhesive dentistry, as practiced in Australia, emphasizes minimal intervention and preservation of tooth structure. Cavity preparations for composite resin rely on micromechanical bonding, not macromechanical retention. Therefore, the design should be dictated by the extent of the caries, removing only the infected tooth structure. Rounded internal line angles help to reduce stress concentration within the restorative material and the tooth, improving the longevity of the restoration.

Question 102: A patient on warfarin requires a simple extraction. What is the recommended INR threshold below which extraction can proceed safely in most cases?

INR < 2.0
INR < 3.5 (Correct answer)
INR < 1.5
INR < 4.0

Correct answer: INR < 3.5

Current evidence-based guidelines recommend that simple dental extractions can be performed safely when INR is below 3.5 with appropriate local haemostatic measures.

Question 103: A 68-year-old patient with a history of poorly controlled asthma and a previous gastric ulcer requires post-operative analgesia following a surgical extraction. Which of the following is the most appropriate medication to prescribe for moderate pain?

Mefenamic Acid 500mg
Aspirin 300mg
Ibuprofen 400mg
Paracetamol 1000mg (Correct answer)

Correct answer: Paracetamol 1000mg

Paracetamol is the most appropriate analgesic choice. Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, aspirin, and mefenamic acid are contraindicated in this patient. NSAIDs can precipitate bronchospasm in individuals with asthma and are known to cause gastric irritation, which could exacerbate or reactivate a gastric ulcer.

Question 104: A 22-year-old patient presents with severe pain, trismus, and swelling associated with a partially erupted tooth 38. There is purulent discharge from under the operculum. Which of the following is the most appropriate initial management for this acute pericoronitis?

Gentle irrigation under the operculum and debridement, with antibiotics reserved for systemic signs. (Correct answer)
Incision and drainage of the operculum without local anaesthesia to avoid spread of infection.
Prescribing a course of analgesics only and reviewing the patient in one week.
Immediate surgical extraction of tooth 38 to remove the definitive cause.

Correct answer: Gentle irrigation under the operculum and debridement, with antibiotics reserved for systemic signs.

The initial management of acute pericoronitis focuses on resolving the acute inflammatory and infectious process before definitive treatment. This involves local measures, primarily gentle irrigation of the sub-opercular space with saline or an antiseptic solution to remove debris and reduce the bacterial load. Systemic antibiotics are only indicated if there are signs of systemic involvement (e.g., fever, lymphadenopathy, severe trismus) or spreading infection. Extraction is deferred until the acute phase is controlled.

Question 105: Which permanent tooth has the longest root?

Mandibular first molar
Maxillary first molar
Maxillary central incisor
Maxillary canine (Correct answer)

Correct answer: Maxillary canine

The maxillary canine has the longest root of all permanent teeth, contributing to its stability and longevity.

Question 106: Etching enamel with 37% phosphoric acid for 15–30 seconds results in:

Removal of the entire prismatic layer to expose interprism enamel
Selective dissolution of enamel crystallite cores or peripheries creating microporosities for resin infiltration (Correct answer)
Complete removal of enamel rods and formation of a chemical bond with fluoride ions
Surface glazing that improves wettability

Correct answer: Selective dissolution of enamel crystallite cores or peripheries creating microporosities for resin infiltration

Phosphoric acid produces a type I, II, or III etch pattern by preferentially dissolving enamel prism cores or peripheries, creating micropores 5–50 µm deep that allow resin tags to form and provide micromechanical bonding.

Question 107: A large, multilocular radiolucency is noted in the posterior mandible of a 25-year-old male, extending into the ramus. A biopsy is performed. Which of the following histopathological features is most characteristic of an Odontogenic Keratocyst (OKC)?

Mucous-producing cells and pools of mucin
A thin, uniform parakeratinised epithelial lining with a palisaded, hyperchromatic basal cell layer (Correct answer)
Presence of ghost cells and dystrophic calcification
An inflamed fibrous capsule with prominent, arcading rete ridges

Correct answer: A thin, uniform parakeratinised epithelial lining with a palisaded, hyperchromatic basal cell layer

The histopathological hallmark of an OKC is its unique epithelial lining. It is typically thin and uniform (around 5-8 cells thick), parakeratinised, and features a prominent, palisaded basal cell layer composed of hyperchromatic (darkly stained) columnar or cuboidal cells. Ghost cells are characteristic of Calcifying Odontogenic Cysts (Gorlin cyst). Mucous cells are found in Glandular Odontogenic Cysts or Mucoepidermoid Carcinomas. An inflamed capsule with arcading rete ridges is typical of an inflammatory cyst like a radicular cyst.

Question 108: The bond strength of fourth-generation (total-etch, three-step) dentin bonding agents depends primarily on:

Ionic bonding between the primer and calcium ions in dentin mineral
Covalent crosslinking between the adhesive and dentin collagen fibers
Chemical adsorption of the adhesive to residual hydroxyapatite only
Micromechanical interlocking via the hybrid layer formed by resin infiltration of demineralized dentin collagen (Correct answer)

Correct answer: Micromechanical interlocking via the hybrid layer formed by resin infiltration of demineralized dentin collagen

Total-etch systems remove the smear layer and demineralize dentin, allowing primer/adhesive monomers to infiltrate and polymerize within exposed collagen fibers, creating a hybrid layer that provides micromechanical retention.

Question 109: A 7-year-old child presents for their first dental visit. Clinical examination reveals deep, sticky fissures on the permanent first molars (16, 26, 36, 46) with no radiographic evidence of caries. According to contemporary Australian caries management guidelines, what is the most appropriate initial management?

Prescribing a high-fluoride toothpaste (5000 ppm) for daily use.
Placing prophylactic amalgam restorations in all fissures.
Scheduling the patient for a six-month review with no active treatment.
Applying a high-viscosity glass ionomer cement as a fissure sealant. (Correct answer)

Correct answer: Applying a high-viscosity glass ionomer cement as a fissure sealant.

For a child with high-risk, deep fissures, a fissure sealant is the standard preventive measure. High-viscosity glass ionomer cements (GICs) are an excellent choice, especially in situations where moisture control can be challenging, as in a young child. GICs offer the significant advantage of fluoride release, which can help in the maturation of the enamel and provide protection against caries. Australian guidelines emphasize minimal intervention and prevention, making GIC sealants a preferred option over restorative intervention or simply observing.

Question 110: Which of the following is/are true regarding a tooth filled with a formaldehyde-containing paste?

Formaldehyde-containing pastes have a high antigenic potential.
All of the above. (Correct answer)
Formaldehyde-containing pastes remain non-approved.
There are cases on record of paresthesia following over extrusion of such a paste in the vicinity of the mandibular nerve.
The drug manufacturer may be liable, along with the dentist.

Correct answer: All of the above.

Explanation: Statements a, b, c, and d are all factually correct and provide accurate information about the use and potential risks of formaldehyde-containing pastes in dentistry.

Question 111: A 65-year-old patient on long-term warfarin therapy for atrial fibrillation requires a simple extraction of tooth 36. His recent INR reading is 2.8. According to Australian Therapeutic Guidelines, what is the most appropriate management plan?

Proceed with the extraction using effective local haemostatic measures. (Correct answer)
Defer the extraction and advise the patient to cease warfarin for 3 days prior.
Ask the patient to halve their warfarin dose for 24 hours before the procedure.
Refer the patient to a hospital for the extraction under general anaesthesia.

Correct answer: Proceed with the extraction using effective local haemostatic measures.

Australian and international guidelines recommend that for simple extractions (1-3 teeth), patients with a therapeutic INR up to 4.0 can proceed without altering their warfarin regimen. The risk of a thromboembolic event from stopping warfarin far outweighs the risk of post-operative bleeding, which can be managed effectively with local measures such as packing the socket with a haemostatic agent and suturing.

Question 112: Which ASA classification would be assigned to a patient with well-controlled Type 2 diabetes and no other systemic conditions?

ASA IV
ASA III
ASA II (Correct answer)
ASA I

Correct answer: ASA II

A patient with well-controlled diabetes and no significant limitations is classified ASA II — mild systemic disease.

Question 113: A dentist is performing root canal treatment on a maxillary first molar. After creating the access cavity and beginning instrumentation, they notice a small, persistent hemorrhage from the pulpal floor, mesial to the main mesiobuccal canal orifice. Which of the following procedural errors is the most likely cause?

Missing the second mesiobuccal (MB2) canal
Perforation into the furcation (Correct answer)
Fracture of an endodontic instrument
A lateral perforation of the root

Correct answer: Perforation into the furcation

A perforation into the furcation area is a common procedural error during access cavity preparation in molars. It occurs when the bur is directed too deeply or at an incorrect angle, breaching the pulpal floor and entering the periodontal ligament space in the furcation. This typically results in persistent hemorrhage that is difficult to control. Missing a canal or a fractured instrument would not typically present with bleeding from the pulpal floor itself.

Question 114: A 30-year-old patient requires a single full-coverage crown on tooth 11 and is primarily concerned with achieving the best possible aesthetics. The tooth has sufficient coronal structure, and there are no signs of parafunctional habits. Which all-ceramic material would be the most appropriate choice to primarily meet the patient's aesthetic demands?

Lithium disilicate (e.g., IPS e.max). (Correct answer)
Monolithic high-strength zirconia.
A gold alloy.
Porcelain-fused-to-metal (PFM).

Correct answer: Lithium disilicate (e.g., IPS e.max).

Lithium disilicate offers an excellent combination of high translucency, strength, and favorable optical properties, making it a superior choice for highly aesthetic single anterior crowns. Monolithic zirconia, while very strong, is typically more opaque and less ideal for single anterior teeth where aesthetics are paramount. PFM and gold crowns do not offer the same level of aesthetics as modern all-ceramic options for the anterior region.

Question 115: During root canal treatment, which of the following is the primary function of sodium hypochlorite (NaOCl) as an irrigant?

Removal of the smear layer
Chelation of inorganic dentine components
Lubrication of endodontic files
Dissolution of organic tissue and antimicrobial action (Correct answer)

Correct answer: Dissolution of organic tissue and antimicrobial action

Sodium hypochlorite's primary and most crucial roles in endodontics are its ability to dissolve necrotic and vital pulp tissue (organic components) and its potent broad-spectrum antimicrobial activity against bacteria and biofilms within the root canal system. While it has some lubricating effect, this is not its primary function. Removal of the smear layer (inorganic component) is primarily achieved by chelating agents like EDTA.

Question 116: A healthy 50kg adult patient requires extensive local anaesthesia for a procedure using 2% Lidocaine with 1:100,000 adrenaline. What is the absolute maximum number of standard 2.2mL Australian dental cartridges that can be safely administered?

13 cartridges
10 cartridges
5 cartridges
7 cartridges (Correct answer)

Correct answer: 7 cartridges

The maximum recommended dose of Lidocaine with a vasoconstrictor is 7 mg/kg. For a 50kg patient, the total maximum dose is 50 kg * 7 mg/kg = 350 mg. A standard Australian 2.2mL cartridge of 2% Lidocaine contains 44 mg of the drug (20 mg/mL * 2.2 mL). Therefore, the maximum number of cartridges is 350 mg / 44 mg/cartridge = 7.95. The maximum number of full cartridges that can be safely administered is 7.

Question 117: A patient reports biting the inside of their cheek repeatedly and presents with a nodule on the buccal mucosa. What is the most likely diagnosis?

Lipoma
Fibroma (irritation fibroma) (Correct answer)
Pleomorphic adenoma
Mucocele

Correct answer: Fibroma (irritation fibroma)

Repeated trauma from cheek biting commonly causes reactive fibrous hyperplasia (irritation fibroma), the most common benign soft tissue lesion in the oral cavity.

Question 118: When assessing a patient's periodontal status, what does a pocket depth of 6 mm with bleeding on probing most likely indicate?

Healthy sulcus with pseudo-pocketing due to gingival overgrowth
Early gingivitis only
Normal pocket depth within acceptable limits
Active periodontal disease with likely bone loss (Correct answer)

Correct answer: Active periodontal disease with likely bone loss

A probing depth of 6 mm combined with bleeding on probing indicates active periodontitis with probable alveolar bone loss requiring further investigation and treatment.

Question 119: Case scenario: Alexander, a 64-year-old patient who is receiving warfarin as part of the management of his atrial fibrillation tells you that one of his lower right back teeth was restored three years ago by a dentist who has since retired from your practice. The tooth is now occasionally sensitive to hot and cold. The clinical notes confirm the history and indicate that the tooth was restored using a resin composite material. You obtain the periapical radiograph. You decided to extract the tooth and in planning for the procedure you find that the patient’s International normalized ratio (INR) is 2.4. What is the most appropriate action to take at this time?

Refer to patient to a consultant Oral and Maxillofacial Surgeon who is best placed to manage complex surgical problems such as this
Proceed with the extraction and provide appropriate post-operative instructions (Correct answer)
Consult the patient’s cardiologist to discuss stopping their warfarin treatment
Proceed with the extraction and suggest that the patient stop their warfarin for 3 days
Suggest that the patient stop their warfarin and commence taking 125mg aspirin before returning in 3 days to have the tooth removed

Correct answer: Proceed with the extraction and provide appropriate post-operative instructions

Explanation: Since the INR is within the acceptable range for dental extractions, proceeding with the extraction and providing appropriate post-operative instructions would be the most appropriate action.

Question 120: An orthopantomogram (OPG) of an asymptomatic 18-year-old reveals a well-defined, corticated, unilocular radiolucency surrounding the crown of an unerupted mandibular third molar. The lesion appears attached at the cementoenamel junction. What is the most likely radiographic diagnosis?

Radicular Cyst
Dentigerous Cyst (Correct answer)
Odontogenic Keratocyst (OKC)
Ameloblastoma

Correct answer: Dentigerous Cyst

A dentigerous (or follicular) cyst is the most common developmental odontogenic cyst and is characteristically associated with the crown of an unerupted or impacted tooth. Radiographically, it presents as a well-defined, unilocular radiolucency with a sclerotic border attached at the cementoenamel junction. A radicular cyst is associated with a non-vital tooth, while ameloblastomas and OKCs, although they can appear in this location, are less common, and OKCs may have a more aggressive growth pattern.

Question 121: Which of the following is the primary goal of non-surgical periodontal therapy, such as scaling and root planing?

To disrupt the subgingival biofilm and remove calculus deposits. (Correct answer)
To eliminate the need for any future dental treatment.
To regenerate lost alveolar bone and cementum.
To achieve a smooth root surface for patient comfort.

Correct answer: To disrupt the subgingival biofilm and remove calculus deposits.

The fundamental objective of non-surgical periodontal therapy is to remove the primary etiological factors of periodontitis, which are the bacterial biofilm (plaque) and calculus (hardened plaque) from the root surfaces. This process aims to reduce the bacterial load, resolve inflammation, and create an environment conducive to healing, which may result in the reduction of probing depths. While regeneration is a goal of some surgical procedures, it is not the primary aim of non-surgical debridement.

Question 122: A 9-year-old child presents with an uncomplicated crown fracture of the maxillary right central incisor (tooth 11) following a fall. The fracture exposes a small area of vital dentine but not the pulp. The tooth is not mobile, and pulp vitality testing is positive. According to the International Association of Dental Traumatology (IADT) guidelines, what is the most appropriate immediate management?

Initiate a Cvek (partial) pulpotomy.
Extract the tooth and consider a space maintainer.
Perform a direct pulp cap with MTA and restore.
Place a calcium hydroxide liner over the exposed dentine and restore with composite resin. (Correct answer)

Correct answer: Place a calcium hydroxide liner over the exposed dentine and restore with composite resin.

For an uncomplicated crown fracture with dentine exposure, the primary goal is to seal the dentinal tubules to prevent bacterial ingress and protect the pulp. Placing a calcium hydroxide liner or a glass ionomer base over the exposed dentine, followed by a definitive restoration with composite resin, is the standard of care. Direct pulp capping or pulpotomy is only indicated if there is a pulp exposure (complicated crown fracture). Extraction is not indicated as the tooth is restorable and vital.

Question 123: Addition silicone (polyvinyl siloxane) impression materials have superior dimensional stability compared to condensation silicones because:

They contain more filler particles
Their addition polymerization produces no volatile by-products (Correct answer)
They absorb water from the oral environment
They have a much lower viscosity

Correct answer: Their addition polymerization produces no volatile by-products

Addition silicones polymerize without releasing any by-products, so there is no volume loss after setting, resulting in excellent long-term dimensional accuracy.

Question 124: Which clinical sign is MOST indicative of a non-vital tooth?

Mild pain on biting
Slight mobility of the tooth
Presence of a deep cavity
Negative response to electric pulp testing and cold testing (Correct answer)

Correct answer: Negative response to electric pulp testing and cold testing

A negative response to both electric pulp testing and cold thermal testing strongly indicates pulpal necrosis (non-vitality).

Question 125: According to the 2017 AAP/EFP classification system, which factor is a primary determinant for assigning the 'Grade' of periodontitis?

The percentage of bone loss at the most affected site.
The presence of probing depths greater than 5 mm.
The number of teeth lost due to periodontitis.
The rate of disease progression over time. (Correct answer)

Correct answer: The rate of disease progression over time.

The 'Grade' (A, B, or C) in the current classification system is designed to estimate the future risk and rate of progression of the disease. This is determined by assessing direct or indirect evidence of progression, such as longitudinal data (radiographs or probing depths over time) or by using metrics like the percentage of bone loss divided by the patient's age. The other factors, such as tooth loss and probing depths, are primarily used to determine the 'Stage' (I-IV) of the disease, which relates to severity and complexity.

Question 126: A 6-year-old child requires extraction of the mandibular right primary second molar (tooth 85) due to an abscess. The permanent first molar (tooth 46) has not yet erupted but is visible on the radiograph. To prevent mesial migration and impaction of the unerupted permanent molar, what is the most appropriate space management appliance?

Lower lingual holding arch
Band and loop space maintainer
Nance appliance
Distal shoe space maintainer (Correct answer)

Correct answer: Distal shoe space maintainer

The distal shoe space maintainer is specifically indicated for the premature loss of a primary second molar BEFORE the eruption of the permanent first molar. It has a subgingival extension (the 'shoe') that physically guides the unerupted permanent first molar into its correct position. A band and loop is used after the permanent molar has erupted. A Nance appliance is for the maxillary arch, and a lingual holding arch is typically used for bilateral posterior space loss in the mandible after the permanent incisors have erupted.

Question 127: The flexural strength of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) used in dental frameworks is approximately:

900–1200 MPa (Correct answer)
2500–3000 MPa
200–350 MPa
50–100 MPa

Correct answer: 900–1200 MPa

Y-TZP exhibits a flexural strength of approximately 900–1200 MPa due to its transformation-toughening mechanism, making it the strongest clinical dental ceramic.

Question 128: What is the purpose of a diagnostic wax-up before commencing complex restorative treatment?

To visualise and communicate the proposed changes in occlusion, aesthetics, and tooth position before any irreversible tooth preparation (Correct answer)
To record the patient's medical history
To finalise the colour of the restorations
To create provisional restorations directly

Correct answer: To visualise and communicate the proposed changes in occlusion, aesthetics, and tooth position before any irreversible tooth preparation

A diagnostic wax-up models the planned outcome on study casts, allowing the clinician and patient to evaluate aesthetics and occlusion before any irreversible procedures are performed.

Question 129: Which of the following BEST describes the 'risk assessment' component of a modern dental treatment plan?

Assessment limited to radiographic findings only
A financial estimate provided to the patient before treatment begins
A list of all procedures to be performed
An evaluation of the patient's caries risk, periodontal risk, systemic health, and compliance to prioritize and modify treatment (Correct answer)

Correct answer: An evaluation of the patient's caries risk, periodontal risk, systemic health, and compliance to prioritize and modify treatment

Risk assessment in modern dentistry evaluates individual patient risk factors (caries, periodontal, systemic, behavioral) to tailor the prevention strategy and treatment sequence to that patient's needs.

Question 130: Case scenario: Alexander, a 64-year-old patient who is receiving warfarin as part of the management of his atrial fibrillation tells you that one of his lower right back teeth was restored three years ago by a dentist who has since retired from your practice. The tooth is now occasionally sensitive to hot and cold. The clinical notes confirm the history and indicate that the tooth was restored using a resin composite material. You obtain the periapical radiograph. In this case, what is most likely to cause the failure of the class II composite restorations of the posterior teeth?

The gingival margin on dentine because bonding under these conditions is unpredictable (Correct answer)
Occlusal loads applied to the marginal ridge due to the flexure of the material
Material is placed in increments because of the risk of leakage between the increments
Extended curing time due to greater shrinkage of the material
Glass-ionomer lining is used because of the risk that the lining will leach out over time

Correct answer: The gingival margin on dentine because bonding under these conditions is unpredictable

Explanation: Bonding to dentin, especially near the gingival margin, can be challenging and unpredictable due to factors like moisture control and the presence of dentinal tubules, which may affect the integrity of the restoration over time. Therefore, it is the most likely cause of failure for class II composite restorations in posterior teeth.

Question 131: The canine guidance (cuspid protected occlusion) means:

The canines bear all lateral occlusal forces and disengage posterior teeth (Correct answer)
All teeth share equal contact during lateral excursion
Posterior teeth guide lateral movements
The incisors protect the canines during lateral movement

Correct answer: The canines bear all lateral occlusal forces and disengage posterior teeth

In canine guidance, the canines bear lateral occlusal forces and cause disclusion of all posterior teeth during lateral excursions.

Question 132: For a porcelain-fused-to-metal (PFM) restoration to resist porcelain fracture during firing and function, the metal alloy must:

Have a much higher melting point than the porcelain
Have a coefficient of thermal expansion (CTE) close to that of the veneering porcelain (Correct answer)
Contain at least 75% gold by weight
Have low hardness so porcelain can indent it slightly

Correct answer: Have a coefficient of thermal expansion (CTE) close to that of the veneering porcelain

Compatible CTEs (metal slightly higher than porcelain) place the porcelain in slight compression on cooling, which glass ceramics tolerate well; large CTE mismatches cause tensile stresses that crack the porcelain.

Question 133: The recommended casting temperature for most dental gold alloys is:

Approximately 100–150°C above the liquidus temperature (Correct answer)
Equal to the solidus temperature of the alloy
Approximately 50°C below the liquidus temperature
Equal to the liquidus temperature of the alloy

Correct answer: Approximately 100–150°C above the liquidus temperature

Casting at 100–150°C above the liquidus provides enough superheat to ensure the alloy remains fully fluid, fills all mold details, and allows complete compensation for heat loss during casting without premature solidification.

Question 134: What is the significance of a sinus tract (fistula) found in the oral mucosa?

It is a normal anatomical variant in adults
It indicates a chronic infection with a draining pathway, often from a necrotic pulp or abscess (Correct answer)
It only occurs in association with impacted teeth
It always indicates acute infection requiring immediate extraction

Correct answer: It indicates a chronic infection with a draining pathway, often from a necrotic pulp or abscess

A sinus tract is a channel through which chronic infection drains, most commonly originating from a periapical abscess of a non-vital tooth.

Question 135: The setting reaction of conventional glass ionomer cement (GIC) is best described as:

Acid-base reaction between polyacrylic acid and fluoroaluminosilicate glass (Correct answer)
Condensation polymerization releasing water
Hydration of calcium silicate phases
Free-radical polymerization of an acrylic monomer

Correct answer: Acid-base reaction between polyacrylic acid and fluoroaluminosilicate glass

Conventional GIC sets via an acid-base reaction where polyacrylic acid attacks the glass powder, releasing ions that cross-link the polymer chains and harden the cement.

Question 136: A 45-year-old patient with a high caries risk presents with a Class II lesion on tooth 46. The distal marginal ridge is intact, but the caries extends gingivally below the cementoenamel junction (CEJ). Considering a minimally invasive approach and the patient's risk profile, which of the following is the most appropriate restorative technique for the Australian context?

A full-coverage gold crown to provide maximum durability.
A conventional Class II amalgam restoration with retentive grooves.
A direct composite resin restoration, ensuring meticulous isolation and bonding to the gingival margin.
An open 'sandwich' technique, using glass ionomer cement (GIC) to restore the gingival portion and layering composite resin occlusally. (Correct answer)

Correct answer: An open 'sandwich' technique, using glass ionomer cement (GIC) to restore the gingival portion and layering composite resin occlusally.

The 'sandwich' technique is a well-established procedure in Australian dental practice, particularly for deep Class II cavities with subgingival margins. Using glass ionomer cement (GIC) at the gingival margin offers several advantages in a high-caries-risk patient: it chemically bonds to dentin and enamel, releases fluoride to inhibit recurrent caries, and has a coefficient of thermal expansion similar to that of tooth structure. The occlusal composite layer then provides superior aesthetics and wear resistance.

Question 137: For a full-coverage all-ceramic posterior crown requiring maximum fracture resistance in a high-occlusal-load patient, the most appropriate ceramic system is:

Leucite-reinforced glass ceramic (IPS Empress)
Feldspathic porcelain
Yttria-stabilized tetragonal zirconia (Y-TZP) (Correct answer)
Lithium disilicate glass ceramic (IPS e.max)

Correct answer: Yttria-stabilized tetragonal zirconia (Y-TZP)

Y-TZP has the highest flexural strength (900–1200 MPa) of all dental ceramics, making it the best choice for posterior crowns under high occlusal loads, though its opacity may limit anterior esthetic use.

Question 138: The transformation toughening mechanism of Y-TZP zirconia involves:

Stress-induced tetragonal-to-monoclinic phase transformation that absorbs fracture energy (Correct answer)
Addition of alumina to fill grain boundaries
Yttria permanently preventing any crystallographic phase change
Sintering at ultra-high temperatures to eliminate porosity

Correct answer: Stress-induced tetragonal-to-monoclinic phase transformation that absorbs fracture energy

When a crack propagates in Y-TZP, the tensile stress at the crack tip triggers a tetragonal-to-monoclinic transformation accompanied by ~4% volume expansion that closes the crack and absorbs energy.

Question 139: Which of the following is a fundamental principle for designing a full-thickness mucoperiosteal flap for a surgical extraction?

Releasing incisions, if used, should be placed over the mid-buccal of adjacent teeth.
The base of the flap should be narrower than the free margin to minimise bleeding.
The flap must be wide enough to allow for tension-free retraction and good visibility. (Correct answer)
The periosteum should be carefully left attached to the bone to accelerate healing.

Correct answer: The flap must be wide enough to allow for tension-free retraction and good visibility.

A critical principle of flap design is to ensure adequate access and visibility of the surgical site. The flap must be large enough to be retracted without tension, as excessive tension can tear the tissue or compromise its blood supply, leading to delayed healing or necrosis. To ensure adequate blood supply, the base of the flap must always be wider than its free margin. A full-thickness flap, by definition, includes the periosteum.

Question 140: A dentist is performing a procedure involving a high-speed handpiece, which is known to generate significant aerosols. To comply with standard and transmission-based precautions in Australia, what is the minimum required Personal Protective Equipment (PPE)?

Gloves and a standard surgical mask.
Gloves, a standard surgical mask, and protective eyewear.
A P2/N95 respirator and gloves only.
Gloves, a fluid-resistant gown, protective eyewear or face shield, and a P2/N95 respirator. (Correct answer)

Correct answer: Gloves, a fluid-resistant gown, protective eyewear or face shield, and a P2/N95 respirator.

Aerosol-generating procedures (AGPs) require a high level of protection for the operator. This includes protecting the hands (gloves), body/clothing (gown), and all mucous membranes of the face (eyes, nose, mouth). For aerosols, a P2/N95 respirator is the standard of care over a surgical mask to protect the respiratory tract from inhalation of fine infectious particles.

Question 141: A 4-year-old anxious child has a cavitated carious lesion on a primary molar with no signs of irreversible pulpitis. As a non-invasive management option that avoids local anaesthesia and tooth preparation, the clinician decides to cement a pre-formed metal crown over the tooth. What is this technique called?

Silver Diamine Fluoride (SDF) Application
Atraumatic Restorative Treatment (ART)
Interim Therapeutic Restoration (ITR)
The Hall Technique (Correct answer)

Correct answer: The Hall Technique

The Hall Technique is a specific, evidence-based method for managing carious primary molars by cementing a pre-formed stainless steel crown over the tooth without local anaesthesia, caries removal, or tooth preparation. It works by sealing the lesion from the oral environment, thus arresting the caries process. SDF is a liquid used to arrest caries but is not a restoration. ART and ITR involve caries removal (to varying extents) and placement of a restorative material like glass ionomer cement.

Question 142: What is the significance of a positive response to cold thermal testing in a tooth with a deep carious lesion?

The tooth is non-vital and requires extraction
Cold response indicates a normal, healthy tooth with no need for further investigation
It rules out any periapical pathology
The pulp is still vital, though it may be inflamed (reversible or irreversible pulpitis) (Correct answer)

Correct answer: The pulp is still vital, though it may be inflamed (reversible or irreversible pulpitis)

A positive response to cold testing indicates a vital pulp; however, the quality and duration of response help differentiate reversible pulpitis (brief, sharp pain) from irreversible pulpitis (lingering pain).

Question 143: When examining a patient for temporomandibular disorder (TMD), which finding is most significant?

Mild muscle soreness only on palpation
Clicking sound only on mouth opening
Slightly reduced interincisal opening with no pain
Deviation of the mandible on opening with restricted range of motion and pain (Correct answer)

Correct answer: Deviation of the mandible on opening with restricted range of motion and pain

Deviation with restricted opening and pain together suggest significant TMD and warrant thorough investigation and management.

Question 144: Case scenario: Alexander, a 64-year-old patient who is receiving warfarin as part of the management of his atrial fibrillation tells you that one of his lower right back teeth was restored three years ago by a dentist who has since retired from your practice. The tooth is now occasionally sensitive to hot and cold. The clinical notes confirm the history and indicate that the tooth was restored using a resin composite material. You obtain the periapical radiograph. After the removal of the 46, which prosthodontic options would be most appropriate for Alexander?

Replacement with a fixed bridge
Immediate placement and immediate restoration with a dental implant
Replacement with a removable partial denture after the extraction site has healed
No replacement until the patient has had an opportunity to assess their functional and aesthetic concerns (Correct answer)
Replacement with an immediate removable partial denture

Correct answer: No replacement until the patient has had an opportunity to assess their functional and aesthetic concerns

Explanation: Waiting for the patient to assess their functional and aesthetic concerns before deciding on a replacement option is appropriate. It allows the patient time to consider their preferences and needs before proceeding with any prosthodontic treatment.

Question 145: Case scenario: Alexander, a 64-year-old patient who is receiving warfarin as part of the management of his atrial fibrillation tells you that one of his lower right back teeth was restored three years ago by a dentist who has since retired from your practice. The tooth is now occasionally sensitive to hot and cold. The clinical notes confirm the history and indicate that the tooth was restored using a resin composite material. You obtain the periapical radiograph. Given the history and radiographic evidence, what is the best description of the sensitivity to hot and cold you would expect Alexander to report?

Sharp, occurring once or twice per week and only with ice cream and hot coffee
Dull and lingering for 1-2 minutes (Correct answer)
Worse in the morning
Always present but worse after a hot or cold stimulus
Sharp and relieved on removal of the hot or cold stimulus

Correct answer: Dull and lingering for 1-2 minutes

Explanation: "Dull and lingering for 1-2 minutes," is the most appropriate description of the sensitivity to hot and cold expected from Alexander. This description aligns with symptoms commonly associated with reversible pulpitis, indicating that the pulp is irritated but still viable.

Question 146: The principal monomer in most modern dental composite resin systems is:

Triethylene glycol dimethacrylate (TEGDMA) alone
Methyl methacrylate (MMA)
Bisphenol A-glycidyl methacrylate (Bis-GMA) (Correct answer)
Polymethyl methacrylate (PMMA)

Correct answer: Bisphenol A-glycidyl methacrylate (Bis-GMA)

Bis-GMA is the backbone monomer in the majority of composite resins; its high molecular weight and two reactive methacrylate groups produce a rigid, highly cross-linked polymer network.

Question 147: Which diagnostic criterion differentiates reversible from irreversible pulpitis?

Radiographic periapical changes
Pain that lingers more than 30 seconds after removal of the stimulus (Correct answer)
Presence of a carious lesion
Severity of pain on cold stimulus

Correct answer: Pain that lingers more than 30 seconds after removal of the stimulus

In irreversible pulpitis, pain persists for more than 30 seconds after the stimulus is removed, indicating the pulp cannot recover.

Question 148: What is the most critical component of the long-term management and success of periodontal therapy?

Initial prescription of systemic antibiotics.
The complexity of the initial surgical procedures.
Use of advanced ultrasonic scaling devices.
Patient adherence to a regular supportive periodontal therapy (SPT) schedule. (Correct answer)

Correct answer: Patient adherence to a regular supportive periodontal therapy (SPT) schedule.

Periodontitis is a chronic disease that cannot be 'cured' but can be controlled. The long-term stability of periodontal health depends critically on preventing the recurrence of infection. This is achieved through a combination of the patient's diligent daily oral hygiene and consistent, lifelong participation in a professionally administered supportive periodontal therapy (SPT) program at individually determined intervals. While other factors contribute to initial success, long-term stability is most dependent on maintenance.

Question 149: Which of the following clinical situations presents the strongest justification for using Cone Beam Computed Tomography (CBCT) over conventional two-dimensional radiography for diagnosis and treatment planning?

Evaluating the precise three-dimensional position of a horizontally impacted maxillary canine and its relationship to the roots of adjacent incisors (Correct answer)
Routine detection of interproximal caries in a patient with a low caries risk
Generalised assessment of periodontal bone levels for a new patient examination
Monitoring the healing of a small, uncomplicated periapical lesion following routine endodontic treatment

Correct answer: Evaluating the precise three-dimensional position of a horizontally impacted maxillary canine and its relationship to the roots of adjacent incisors

CBCT provides a three-dimensional view, which is invaluable for assessing complex spatial relationships. For an impacted canine, CBCT can precisely locate the tooth, assess for root resorption of adjacent teeth (which is difficult on 2D films), and determine its proximity to vital structures. This is critical for safe and effective surgical and orthodontic planning. The other options are typically well-managed with conventional radiography like bitewings and periapicals.

Question 150: Which tooth is known as the 'cornerstone' of the dental arch?

First premolar
Canine (Correct answer)
Lateral incisor
Central incisor

Correct answer: Canine

The canine is called the cornerstone of the dental arch because it is located at the corner of the arch and plays a key role in guiding occlusion.

Question 151: Which composite resin type provides the best surface polish due to its very small filler particle size?

Microfill composite (Correct answer)
Packable composite
Macrofill composite
Flowable composite

Correct answer: Microfill composite

Microfill composites contain colloidal silica particles (0.04–0.4 µm) that allow a very smooth, highly polishable surface, though at the cost of reduced strength.

Question 152: What is the purpose of a facebow transfer in prosthodontic treatment planning?

To determine the shade of the patient's teeth
To relate the maxillary cast to the hinge axis of the articulator, replicating the patient's jaw movements (Correct answer)
To measure the patient's facial symmetry
To record the vertical dimension of occlusion

Correct answer: To relate the maxillary cast to the hinge axis of the articulator, replicating the patient's jaw movements

A facebow records the spatial relationship of the maxillary arch to the temporomandibular joint, allowing the dental cast to be mounted on an articulator that mimics the patient's mandibular movements.

Question 153: When root canals are treated topically with antibiotics rather than with disinfectants: 1. A greater success rate results. 2. The same rules of mechanical preparation and filing must be observed. 3. The treatment may be completed in fewer appointments. 4. There is greater assurance that all microorganisms are destroyed. 5. There is a danger of sensitizing patients to antibiotics.

1,2,3
2,4,5
2,5 (Correct answer)
1,3,4

Correct answer: 2,5

Explanation: Statements 2 and 5 are correct as these statements accurately reflect the potential risks and considerations associated with the topical application of antibiotics in root canal treatment.

Question 154: Which structure forms the primary reference point for determining the vertical dimension of occlusion?

The occlusal plane (Correct answer)
The temporomandibular joint condyle
The Frankfort horizontal plane
The maxillary central incisors

Correct answer: The occlusal plane

The occlusal plane is the primary clinical reference used to assess and re-establish vertical dimension of occlusion.

Question 155: A 28-year-old female patient is diagnosed with generalised Stage III Grade C (aggressive) periodontitis. Following initial non-surgical debridement (scaling and root planing), which of the following is the most appropriate next step in her management according to current Australian guidelines?

Placement of localised antibiotic chips in all pockets deeper than 5mm.
Prescription of systemic antibiotics as an adjunct to the initial therapy. (Correct answer)
A 12-month review to assess the healing response.
Immediate referral for full mouth extraction and implant placement.

Correct answer: Prescription of systemic antibiotics as an adjunct to the initial therapy.

For aggressive forms of periodontitis (now classified under the staging/grading system, often Grade C), systemic antibiotics are frequently used as an adjunct to mechanical debridement to target tissue-invasive bacteria that may not be eliminated by instrumentation alone. A common regimen is amoxicillin and metronidazole. The other options are either too extreme (extraction), too passive (12-month review), or not the primary approach for a generalised aggressive case (localised delivery as a sole adjunct).

Question 156: When taking a final impression for multiple, non-parallel implants intended for a splinted, screw-retained bridge, which technique is generally considered more accurate for capturing the precise three-dimensional orientation of the implants?

Closed-tray impression technique.
A dual-arch (triple tray) impression technique.
Open-tray impression technique. (Correct answer)
Digital scanning with a standard intraoral scanner.

Correct answer: Open-tray impression technique.

The open-tray (or pick-up) technique is generally more accurate for multiple, angulated (non-parallel) implants. The impression copings are directly connected to the impression material and are unscrewed from the implants while the tray is still in the mouth. This method minimizes errors from the potential malpositioning of copings when re-seating them into the impression, which is a risk with the closed-tray (transfer) technique, especially where implant angulation prevents a clear path of insertion.

Question 157: According to the Australian Therapeutic Guidelines, which of the following is the recommended first-line antibiotic therapy for a severe, spreading odontogenic infection (e.g., cellulitis) when definitive dental treatment is likely to be delayed beyond 24 hours?

Phenoxymethylpenicillin alone
Metronidazole alone
Amoxicillin with clavulanate (Correct answer)
Clindamycin

Correct answer: Amoxicillin with clavulanate

For a severe odontogenic infection where the source cannot be immediately managed, the Australian Therapeutic Guidelines recommend broader-spectrum therapy. Amoxicillin with clavulanate provides coverage against common oral aerobes and anaerobes, including beta-lactamase-producing bacteria which are more likely in severe or persistent infections. Penicillin alone may not be sufficient if treatment is delayed, and clindamycin is typically reserved for patients with a severe penicillin hypersensitivity.

ADC Written Exam

The Australian Dental Council (ADC) Written Examination assesses overseas-qualified dentists seeking registration in Australia. It consists of 280 scenario-based multiple-choice questions across four papers over two consecutive days, covering all areas of general dentistry.

280

Questions

480 min

Time Limit

50%

To Pass

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