CDT Exam — Questions and Answers

Question 1: Which finishing bur geometry is preferred for contouring heat-pressed ceramic restorations without introducing micro-cracks?

Rubber polishing wheel without water
Carbide cross-cut finishing bur at high speed
Steel bur with air cooling only
Diamond bur with continuous water irrigation at low speed (Correct answer)

Correct answer: Diamond bur with continuous water irrigation at low speed

Fine diamond burs used with continuous water cooling at low speed minimize frictional heat and prevent thermal micro-cracking in glass ceramics.

Question 2: Galvanic corrosion in the oral cavity most commonly occurs when:

Polishing roughens a metal surface
Two dissimilar metals in contact are present in an electrolytic environment (Correct answer)
A single metal restoration contacts saliva
Noble alloys are used adjacent to ceramics

Correct answer: Two dissimilar metals in contact are present in an electrolytic environment

Galvanic corrosion arises from the electrochemical potential difference between two dissimilar metals in the electrically conductive saliva electrolyte.

Question 3: Which articulator movement is adjusted using a protrusive interocclusal record in a semi-adjustable articulator?

Intercondylar distance setting
Incisal guide angle
Condylar inclination (sagittal condylar guidance angle) (Correct answer)
Bennett angle (lateral translation of the condyle)

Correct answer: Condylar inclination (sagittal condylar guidance angle)

A protrusive interocclusal record is used to program the condylar inclination (sagittal condylar path) of a semi-adjustable articulator.

Question 4: During complete denture fabrication, which occlusal scheme is most commonly recommended for edentulous patients to maximize stability during function?

Lingualized occlusion
Canine-guided occlusion
Group function occlusion
Bilateral balanced occlusion (Correct answer)

Correct answer: Bilateral balanced occlusion

Bilateral balanced occlusion provides simultaneous posterior contact on both sides in all excursive movements, minimizing tipping forces and maximizing denture stability.

Question 5: What is the function of the lingual fossa on maxillary anterior teeth in terms of dental occlusion?

It houses the pulp chamber extension
It accommodates the lower canine tip in intercuspation
It guides mandibular incisal edges during protrusive movements (Correct answer)
It provides primary centric stop contact in Class I occlusion

Correct answer: It guides mandibular incisal edges during protrusive movements

The lingual fossae of maxillary anterior teeth guide the incisal edges of mandibular anteriors during protrusive (anterior) excursive movements.

Question 6: When fabricating a screw-retained implant crown, the screw access channel is typically sealed with which material after final torquing?

Composite resin over PTFE tape (Correct answer)
Zinc phosphate cement
Amalgam
Glass ionomer cement

Correct answer: Composite resin over PTFE tape

PTFE (Teflon) tape is placed over the screw head followed by composite resin to allow future access while sealing the channel.

Question 7: What is the Vickers Hardness Number (VHN) scale primarily used to assess in dental alloys?

Tarnish susceptibility
Resistance to surface indentation (Correct answer)
Casting shrinkage
Thermal conductivity

Correct answer: Resistance to surface indentation

The Vickers Hardness test measures a material's resistance to permanent deformation when a diamond indenter is pressed into its surface.

Question 8: Which porcelain defect is characterized by small pits or craters on the fired surface?

Crazing
Pinholes (pitting) (Correct answer)
Delamination
Crawling

Correct answer: Pinholes (pitting)

Pinholes result from trapped gases escaping during firing, often caused by contamination or improper porcelain condensation.

Question 9: What is a common reason for relining a denture?

To change tooth color.
To make it heavier.
To increase biting force.
To improve fit due to tissue changes (Correct answer)

Correct answer: To improve fit due to tissue changes

Over time, the bone and soft tissues in a patient's mouth can resorb and change shape, causing a denture to become loose and ill-fitting. Relining involves adding new acrylic material to the tissue-fitting surface of the denture base to re-establish a snug and comfortable fit. This process improves the denture's retention and stability, enhancing comfort and function without requiring the fabrication of an entirely new denture.

Question 10: What is 'metamerism' in shade matching?

The tendency of porcelain to crack under thermal cycling
Two colors that appear to match under one light source but differ under another (Correct answer)
A technique for blending incisal and body porcelains
The chemical reaction between metal and porcelain during firing

Correct answer: Two colors that appear to match under one light source but differ under another

Metamerism occurs when two materials look like the same color under one light condition (e.g., dental light) but differ under another (e.g., natural daylight).

Question 11: Why are porcelain denture teeth rarely used in modern complete denture fabrication?

They cannot be ground or adjusted in the lab
They are difficult to bond to acrylic and generate excessive wear on opposing natural teeth or restorations (Correct answer)
They are too translucent and look unnatural
They are more expensive than acrylic teeth

Correct answer: They are difficult to bond to acrylic and generate excessive wear on opposing natural teeth or restorations

Porcelain teeth lack chemical bonding to the acrylic base, rely on mechanical retention, and can cause accelerated wear of opposing structures.

Question 12: What does a 'wash bake' accomplish in ceramic fabrication?

Removes excess wax from a ceramic coping
Bonds the ceramic to metal with a bonding agent
Applies a thin porcelain wash to correct minor shade discrepancies (Correct answer)
Initiates the sintering of zirconia

Correct answer: Applies a thin porcelain wash to correct minor shade discrepancies

A wash bake adds a very thin layer of porcelain to blend or correct localized shade or surface irregularities before glazing.

Question 13: What is the Bennett movement in mandibular kinematics?

The protrusive translation of both condyles forward
The bodily lateral shift of the mandible during lateral excursion (Correct answer)
The vertical drop of the condyle during mouth opening
The closing arc of the mandible in terminal hinge position

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

The Bennett movement is the bodily lateral shift of the mandible that occurs during lateral excursion, which is important for setting the Bennett angle on adjustable articulators.

Question 14: In the All-on-4 treatment concept, the two posterior implants are typically placed at what angle to increase bone engagement and avoid anatomical structures?

30 degrees
60 degrees
15 degrees
45 degrees (Correct answer)

Correct answer: 45 degrees

Posterior implants in the All-on-4 concept are tilted 45 degrees to engage more bone and avoid the maxillary sinus or mandibular nerve without grafting.

Question 15: A patient presents with a severely resorbed mandibular ridge. Which denture base design modification can improve retention by extending into the pterygomandibular space?

Retromylohyoid extension (Correct answer)
Labial flange reduction
Sublingual crescent extension
Buccal shelf extension

Correct answer: Retromylohyoid extension

Extending the denture base into the retromylohyoid space (distolingual extension) takes advantage of the anatomical undercut in this region to improve retention on resorbed ridges.

Question 16: A technician observes crazing (surface cracks) in a heat-processed acrylic denture base. This is most likely caused by:

Too slow a heating cycle during processing
Under-packing the mold with acrylic dough
Excessive monomer incorporated during mixing
Rapid cooling after deflasking while still hot (Correct answer)

Correct answer: Rapid cooling after deflasking while still hot

Crazing occurs when thermal stresses exceed the material's strength; rapid quenching after processing induces steep temperature gradients that crack the surface.

Question 17: A dental lab receives a crown back from the dentist because the margin is open. Which corrective action step should come FIRST?

Retrain the technician immediately
Document the nonconformance in the complaint log (Correct answer)
Contact the patient directly
Remake the crown without investigation

Correct answer: Document the nonconformance in the complaint log

Documenting the nonconformance is the first step in any corrective action process to ensure traceability and proper root cause analysis.

Question 18: How should emerging trends in dental anatomy & morphology be incorporated into practice?

By ignoring trends until they become mandatory requirements
Through evidence-based evaluation and systematic integration into existing protocols (Correct answer)
By following only what competitors are doing
By immediately adopting all new trends without evaluation

Correct answer: Through evidence-based evaluation and systematic integration into existing protocols

Evidence-based evaluation ensures new trends are valid and beneficial before integration, maintaining quality while embracing beneficial advances.

Question 19: During RPD framework fabrication, what is the function of a rest seat on an abutment tooth?

To support the framework vertically and prevent tissue-ward movement (Correct answer)
To provide lateral bracing against horizontal forces
To engage the undercut for retention
To guide the path of insertion of the denture

Correct answer: To support the framework vertically and prevent tissue-ward movement

Rest seats accept the occlusal, incisal, or cingulum rests that vertically support the RPD framework, preventing it from settling into soft tissue.

Question 20: What is the recommended firing temperature range for most feldspathic dental porcelains?

700–850°C (Correct answer)
400–600°C
900–1000°C
1100–1300°C

Correct answer: 700–850°C

Feldspathic dental porcelains typically fire between 700°C and 850°C, depending on the specific formulation and manufacturer guidelines.

Question 21: In the lost-wax casting process, what is the purpose of the 'burnout' stage performed before metal injection?

To expand the investment and compensate for metal shrinkage
To degas the alloy and remove surface oxides
To eliminate the wax pattern and preheat the mold to receive molten metal (Correct answer)
To harden the investment mold to withstand casting pressure

Correct answer: To eliminate the wax pattern and preheat the mold to receive molten metal

Burnout eliminates the wax pattern by incineration and preheats the investment mold, ensuring the molten alloy flows fully into the cavity without premature solidification.

Question 22: The mandibular second premolar most commonly has which occlusal pattern?

Two-cusp (buccal and lingual) pattern only
Four-cusp pattern similar to a molar
Single-cusp pattern with no groove
Three-cusp (Y-type) pattern more frequently than two-cusp (Correct answer)

Correct answer: Three-cusp (Y-type) pattern more frequently than two-cusp

The mandibular second premolar more frequently displays a three-cusp Y-type pattern with one buccal and two lingual cusps than the simpler two-cusp arrangement.

Question 23: The clinical relevance of the glass transition temperature (Tg) in denture base resins is that below Tg the material:

Becomes too soft and flows under bite pressure
Loses its color stability rapidly
Absorbs more water and swells dimensionally
Becomes brittle and more susceptible to fracture from impact (Correct answer)

Correct answer: Becomes brittle and more susceptible to fracture from impact

Below the glass transition temperature, polymer chains are immobile, making the resin rigid but brittle and prone to fracture under impact loads.

Question 24: The Shore A durometer is used to measure hardness of which category of dental materials?

Fired dental porcelain
Cast metal alloys
Flexible silicone and rubber-based materials (Correct answer)
Gypsum stone models

Correct answer: Flexible silicone and rubber-based materials

The Shore A scale measures the hardness of soft, flexible materials like silicones, rubbers, and soft denture liners.

Question 25: Which test best evaluates the resistance of a ceramic material to crack propagation under stress?

Fracture toughness (KIC) measurement (Correct answer)
Vickers hardness test
Diametral tensile strength test
Shore D hardness test

Correct answer: Fracture toughness (KIC) measurement

Fracture toughness (KIC) quantifies a material's resistance to crack propagation, critical for predicting clinical longevity of ceramic restorations.

Question 26: What is a pantograph used for in dental prosthetics?

Recording all three-dimensional mandibular movements to program a fully adjustable articulator (Correct answer)
Measuring the interarch distance for denture construction
Determining ceramic shade by comparing tooth color under different lights
Recording the patient's centric occlusion at the correct vertical dimension

Correct answer: Recording all three-dimensional mandibular movements to program a fully adjustable articulator

A pantograph records the full three-dimensional movements of the mandible in all excursions, providing the data needed to program a fully adjustable articulator.

Question 27: Which cusp is the largest and most prominent on the mandibular first molar?

Distolingual cusp
Distobuccal cusp
Mesiobuccal cusp (Correct answer)
Mesiolingual cusp

Correct answer: Mesiobuccal cusp

The mesiobuccal cusp is the largest cusp on the mandibular first molar, followed by the mesiolingual cusp.

Question 28: What is the primary purpose of applying an opaque layer in a porcelain-fused-to-metal (PFM) restoration?

To mask the metal substrate and establish base shade (Correct answer)
To strengthen the porcelain build-up
To add translucency to the final restoration
To improve marginal fit of the crown

Correct answer: To mask the metal substrate and establish base shade

The opaque layer masks the dark metal coping and creates the foundation shade for the overlying porcelain layers.

Question 29: Which statement best describes the difference between burnishing and polishing in metal finishing?

Both procedures are identical in mechanism
Burnishing removes bulk metal; polishing redistributes surface metal
Polishing increases surface hardness; burnishing reduces it
Burnishing plastically flows and compresses the surface without material removal; polishing removes micro-scratches by abrasion (Correct answer)

Correct answer: Burnishing plastically flows and compresses the surface without material removal; polishing removes micro-scratches by abrasion

Burnishing compresses and flows surface metal to fill micro-defects, while polishing uses progressively finer abrasives to remove surface material and reduce roughness.

Question 30: In dental morphology, what is a 'fissure'?

The line of junction between two lobes
A fault or imperfect fusion at the base of a developmental groove (Correct answer)
A broad, shallow depression on a tooth surface
A ridge connecting two cusps

Correct answer: A fault or imperfect fusion at the base of a developmental groove

A fissure is a cleft or imperfect fusion of the enamel at the base of a groove, resulting from incomplete coalescence of developmental lobes.

Question 31: For a mandibular posterior three-unit bridge, which pontic design provides the best combination of esthetics and cleanability in a patient with a flat, keratinized ridge?

Ovate pontic
Modified ridge-lap pontic (Correct answer)
Ridge-lap pontic
Conical pontic

Correct answer: Modified ridge-lap pontic

The modified ridge-lap pontic offers good esthetics by contacting only the buccal aspect of the ridge while leaving the lingual surface convex for easy hygiene access.

Question 32: What is the primary purpose of using a separating medium on a stone cast before applying wax?

To prevent wax from bonding to the stone (Correct answer)
To disinfect the cast
To improve wax flow characteristics
To strengthen the cast surface

Correct answer: To prevent wax from bonding to the stone

Separating mediums such as tinfoil substitute create a barrier so wax can be removed cleanly without sticking to the stone model.

Question 33: What is the purpose of personal protective equipment (PPE)?

To improve speed of work.
To look professional.
To increase comfort during work.
To protect against infectious agents (Correct answer)

Correct answer: To protect against infectious agents

Personal Protective Equipment (PPE), such as gloves, masks, and eye protection, serves as a vital barrier between the dental technician and potential workplace hazards. In the dental lab, this primarily includes protecting against exposure to infectious agents from impressions or models, as well as safeguarding against chemical splashes, dust, and airborne particles generated during various fabrication processes. PPE is essential for maintaining a safe working environment.

Question 34: Which prosthetic component connects an implant body to the overlying crown or prosthesis and is available in stock or custom forms?

Cover screw
Abutment (Correct answer)
Healing cap
Impression coping

Correct answer: Abutment

The abutment is the intermediary component that attaches to the implant body and provides support and retention for the prosthetic crown or bridge.

Question 35: Which dental structure connects the tooth to the alveolar bone?

Dentin.
Periodontal ligament (Correct answer)
Enamel.
Cementum.

Correct answer: Periodontal ligament

The periodontal ligament (PDL) is a specialized connective tissue that surrounds the root of the tooth and attaches it to the alveolar bone of the jaw. It acts as a shock absorber, distributing occlusal forces, and contains sensory nerves, blood vessels, and cells vital for bone and cementum formation and resorption. This connection is crucial for tooth stability and function.

Question 36: What does 'incoming inspection' of dental materials involve in a QMS-compliant laboratory?

Inspecting only materials above a certain dollar value
Accepting all materials from approved suppliers without inspection
Testing materials only when a complaint is received
Verifying materials meet specifications before use in production (Correct answer)

Correct answer: Verifying materials meet specifications before use in production

Incoming inspection verifies that received materials and components meet specified requirements before they enter the production process.

Question 37: When trimming a diagnostic cast, the posterior heel of a maxillary cast should be:

Parallel to the mid-palatal raphe (Correct answer)
Parallel to the occlusal plane
Angled 20 degrees toward the base
Rounded to prevent breakage

Correct answer: Parallel to the mid-palatal raphe

Trimming the posterior wall parallel to the mid-palatal raphe ensures symmetrical articulator mounting and accurate representation of midline.

Question 38: What does 'chroma' refer to in dental shade selection?

The saturation or intensity of the hue (Correct answer)
The brightness of the tooth under UV light
The surface texture of the enamel
The overall hue category of the tooth (A, B, C, or D)

Correct answer: The saturation or intensity of the hue

Chroma refers to the saturation or strength of the color, indicated by numbers in Vita shades (e.g., A1 = low chroma, A4 = high chroma).

Question 39: The addition of palladium to gold alloys in dental use primarily improves:

Biocompatibility in sensitive patients
Tarnish and corrosion resistance while raising the melting point (Correct answer)
Castability and fluidity of the molten metal
Esthetic shade matching

Correct answer: Tarnish and corrosion resistance while raising the melting point

Palladium acts as a whitening agent, raises the melting range, and significantly improves tarnish and corrosion resistance in gold alloys.

Question 40: What should be done after accidental exposure to blood?

Report and follow post-exposure procedures (Correct answer)
Hide the incident.
Continue working without cleaning.
Ignore it.

Correct answer: Report and follow post-exposure procedures

Accidental exposure to blood, such as a needlestick or splash, carries a significant risk of transmitting bloodborne pathogens. Immediate reporting and following established post-exposure procedures are crucial for prompt medical evaluation, testing, and potential prophylactic treatment. This protocol helps minimize the risk of infection, ensures proper documentation, and facilitates necessary follow-up care.

Question 41: How many roots does the mandibular second molar typically have?

Four
Three
One
Two (Correct answer)

Correct answer: Two

The mandibular second molar typically has two roots — a mesial and a distal root — similar to the mandibular first molar but with less divergence.

Question 42: Why is stakeholder communication important in cad/cam digital dentistry?

It is only relevant for management-level positions
It slows down the implementation process unnecessarily
It is only needed when major changes are being implemented
It ensures alignment of expectations and facilitates collaborative decision-making (Correct answer)

Correct answer: It ensures alignment of expectations and facilitates collaborative decision-making

Stakeholder communication ensures everyone involved has aligned expectations and can contribute to informed, collaborative decision-making.

Question 43: An immediate complete denture is placed:

Only after a tissue conditioner has been worn for 30 days
Six months after all extractions are healed
On the same appointment that remaining teeth are extracted (Correct answer)
After the opposing arch is completed first

Correct answer: On the same appointment that remaining teeth are extracted

Immediate dentures are inserted at the same visit as remaining extractions, allowing the patient to avoid an edentulous period while the ridges heal.

Question 44: Which type of impression technique is most accurate for capturing the position of multiple implants in different axial inclinations?

Open-tray splinted technique using polyether (Correct answer)
Closed-tray snap-on technique
Bite registration wax pickup
Alginate with stock tray

Correct answer: Open-tray splinted technique using polyether

Open-tray splinted impressions with polyether minimize coping displacement and distortion, achieving the highest accuracy for multiple divergent implants.

Question 45: A technician receives a master cast with a fractured die. The best course of action before fabricating the crown is to:

Apply extra die spacer over the fractured area to compensate
Repair the die with sticky wax and proceed with waxing
Use the opposing cast to reconstruct the missing die area
Contact the dentist and request a new impression (Correct answer)

Correct answer: Contact the dentist and request a new impression

A fractured die cannot reliably reproduce the preparation margins, and the only correct course is to request a new impression to ensure an accurate, well-fitting restoration.

Question 46: What is the primary purpose of incorporating ball clasps (bullet clasps) into a removable orthodontic appliance?

To provide retention by engaging embrasures between teeth (Correct answer)
To serve as attachment points for elastics
To act as bite registration stops
To apply tipping forces on teeth

Correct answer: To provide retention by engaging embrasures between teeth

Ball clasps engage the interproximal embrasure between adjacent teeth, providing passive retention for the appliance without wrapping around individual teeth.

Question 47: In a CAD/CAM implant workflow, what is the function of a scan body placed on the implant before intraoral scanning?

To indicate the shade of the final restoration
To record the vertical dimension of occlusion
To protect the implant from contamination during scanning
To encode implant position and angulation in the digital impression (Correct answer)

Correct answer: To encode implant position and angulation in the digital impression

Scan bodies have known geometries that allow CAD software to identify exact implant platform position and angulation.

Question 48: What precaution must be taken when grinding or adjusting ceramic restorations chairside or in the lab?

Use copious water cooling and wear appropriate respiratory protection (Correct answer)
Only use rubber wheels without water
Always use a dry diamond bur at low speed
Grind only with zirconia-specific carbide burs at high speed

Correct answer: Use copious water cooling and wear appropriate respiratory protection

Ceramic dust contains silica and zirconia particles that are hazardous to inhale, requiring water cooling and N95 or better respiratory protection.

Question 49: Which primary (deciduous) tooth has no permanent successor?

None — all primary teeth have successors (Correct answer)
Primary mandibular second molar
Primary maxillary canine
Primary maxillary first molar

Correct answer: None — all primary teeth have successors

Every primary tooth has a permanent successor — the 20 primary teeth are replaced by 20 of the 32 permanent teeth.

Question 50: In constructing a Hawley retainer, the labial bow is most commonly fabricated from which wire gauge?

.014-inch stainless steel
.018-inch stainless steel (Correct answer)
.040-inch stainless steel
.030-inch stainless steel

Correct answer: .018-inch stainless steel

The .018-inch stainless steel wire is the standard for Hawley labial bows, providing sufficient rigidity to maintain arch form while allowing minor adjustments.

Question 51: Which alloy system is most susceptible to green corrosion (verdigris) when used in crown and bridge work?

Palladium-silver alloys
Titanium alloys
Base-metal alloys containing copper (Correct answer)
High-gold alloys

Correct answer: Base-metal alloys containing copper

Base-metal alloys with high copper content are prone to green corrosion (verdigris) due to copper oxide formation in oral environments.

Question 52: When should a dental laboratory technician change gloves during case processing?

Only when gloves become visibly torn
Only at the end of each shift
After handling chemicals only
Between each patient case and when gloves are torn or contaminated (Correct answer)

Correct answer: Between each patient case and when gloves are torn or contaminated

Gloves must be changed between patient cases and whenever they are damaged, torn, or contaminated to prevent cross-contamination.

Question 53: When addressing challenges in implant prosthetics techniques, what approach is most effective?

Waiting for problems to resolve on their own
Quick fixes that address only the immediate symptoms
Applying the same solution regardless of the specific challenge
Systematic analysis of root causes followed by evidence-based solutions (Correct answer)

Correct answer: Systematic analysis of root causes followed by evidence-based solutions

Systematic root cause analysis with evidence-based solutions addresses problems at their source, preventing recurrence and leading to lasting improvement.

Question 54: Denture teeth made of porcelain are preferred over acrylic teeth primarily because they:

Offer superior wear resistance and hardness (Correct answer)
Bond chemically to the acrylic denture base
Are easier to adjust chairside
Provide better shock absorption

Correct answer: Offer superior wear resistance and hardness

Porcelain teeth resist wear better than acrylic teeth, maintaining occlusal vertical dimension over time despite their brittleness and lack of chemical bonding.

Question 55: What is 'sintering' in the context of zirconia processing?

The process of staining pre-sintered zirconia with colorants
Bonding zirconia to a resin cement
Milling zirconia from a pre-sintered puck
High-temperature densification that transforms porous zirconia into a hard, dense ceramic (Correct answer)

Correct answer: High-temperature densification that transforms porous zirconia into a hard, dense ceramic

Sintering fires zirconia at approximately 1,450–1,530°C, driving off porosity and transforming it into its final, hard, dense form.

Question 56: What is the purpose of incorporating a posterior bite plane into an upper removable orthodontic appliance?

To disarticulate the posterior teeth and allow anterior deep bite correction (Correct answer)
To expand the buccal segments
To intrude the posterior teeth
To retract the maxillary incisors

Correct answer: To disarticulate the posterior teeth and allow anterior deep bite correction

A posterior bite plane lifts the posterior teeth out of occlusion, removing their vertical support and allowing the anterior teeth to erupt or the deep bite to reduce via relative eruption mechanics.

Question 57: The elastic modulus (stiffness) of a restorative material is most relevant when evaluating:

Resistance to deformation under occlusal load (Correct answer)
Thermal conductivity to the pulp
Color stability under UV light
Susceptibility to galvanic corrosion

Correct answer: Resistance to deformation under occlusal load

Elastic modulus describes a material's stiffness and its ability to resist deformation under applied occlusal forces.

Question 58: Why are sharps containers used?

To dry instruments.
To reuse sharp instruments.
To increase workspace.
To store disposable sharp items safely (Correct answer)

Correct answer: To store disposable sharp items safely

Sharps containers are rigid, puncture-resistant containers specifically designed for the safe disposal of contaminated sharp items like needles, scalpel blades, and orthodontic wires. Their use is paramount in preventing accidental needlestick injuries to dental professionals and waste handlers. This practice significantly reduces the risk of transmitting bloodborne pathogens and ensures a safer working environment in the dental lab.

Question 59: When fabricating a long-span fixed partial denture, which design strategy is used to manage the difference in flexure between rigid abutments and the pontic span?

Choose a higher-fusing alloy for the framework
Use thicker connectors on the mesial aspect only
Incorporate a stress-breaker or non-rigid connector (Correct answer)
Increase occlusal clearance to reduce loading

Correct answer: Incorporate a stress-breaker or non-rigid connector

A non-rigid (stress-breaker) connector allows slight independent movement between segments, reducing the transmission of torquing forces to abutment teeth with differing mobility.

Question 60: When addressing challenges in dental anatomy & morphology, what approach is most effective?

Waiting for problems to resolve on their own
Quick fixes that address only the immediate symptoms
Applying the same solution regardless of the specific challenge
Systematic analysis of root causes followed by evidence-based solutions (Correct answer)

Correct answer: Systematic analysis of root causes followed by evidence-based solutions

Systematic root cause analysis with evidence-based solutions addresses problems at their source, preventing recurrence and leading to lasting improvement.

Question 61: Under OSHA's Hazard Communication Standard (HazCom 2012), how many sections does a Safety Data Sheet (SDS) contain?

8
20
16 (Correct answer)
12

Correct answer: 16

GHS-aligned SDSs under HazCom 2012 contain exactly 16 standardized sections covering identification, hazards, composition, and safe handling.

Question 62: Under OSHA's Bloodborne Pathogens Standard, which scenario CORRECTLY describes when an employer must offer the hepatitis B vaccine?

Only to employees who specifically request it
At the time of annual performance reviews
Only after an employee reports a needlestick injury
Within 10 working days of initial assignment to tasks involving occupational exposure (Correct answer)

Correct answer: Within 10 working days of initial assignment to tasks involving occupational exposure

Employers must offer the hepatitis B vaccine series at no cost to employees within 10 working days of initial assignment to duties with occupational exposure risk.

Question 63: Which teeth are primarily responsible for grinding food?

Canines.
Lateral incisors.
Incisors.
Molars (Correct answer)

Correct answer: Molars

Molars are the large, flat teeth located at the back of the mouth, distinguished by their broad chewing surfaces and multiple cusps. Their robust structure and wide occlusal tables are perfectly adapted for crushing and grinding food into a fine paste. This makes them essential for the final stages of mastication, facilitating digestion.

Question 64: What is the key principle of standard precautions?

Assume only visibly dirty materials are dangerous.
Skip precautions if rushed.
Only use precautions with known infections.
Treat all fluids as potentially infectious (Correct answer)

Correct answer: Treat all fluids as potentially infectious

Standard precautions are a set of infection control practices where all human blood, body fluids, secretions, excretions (except sweat), non-intact skin, and mucous membranes are treated as potentially infectious. This universal approach ensures that healthcare workers and patients are protected from transmissible infectious agents, regardless of a known diagnosis. It minimizes the risk of disease transmission in any clinical or laboratory setting.

Question 65: What is the minimum contact time for intermediate-level disinfectants (e.g., EPA-registered hospital disinfectant with tuberculocidal claim) on laboratory surfaces?

3 minutes
1 minute
30 seconds
10 minutes (Correct answer)

Correct answer: 10 minutes

Most intermediate-level disinfectants with tuberculocidal claims require a minimum of 10 minutes of wet surface contact to achieve the labeled kill claims.

Question 66: The term 'creep' in dental materials refers to:

Slow plastic deformation under a constant applied stress over time (Correct answer)
Surface discoloration from oxidation
Rapid elastic recovery after load removal
Sudden fracture under impact loading

Correct answer: Slow plastic deformation under a constant applied stress over time

Creep is the time-dependent plastic deformation that occurs in a material subjected to a constant stress, relevant to amalgam marginal breakdown.

Question 67: When constructing an Essix-style clear retainer, the thermoplastic sheet is adapted over the final model using which piece of equipment?

Centrifugal casting unit
Pressure/vacuum forming machine (Biostar or Drufomat) (Correct answer)
Compression mold press
High-pressure autoclave

Correct answer: Pressure/vacuum forming machine (Biostar or Drufomat)

A pressure or vacuum forming machine heats the thermoplastic sheet until pliable, then forces it over the model under vacuum or positive pressure to achieve accurate adaptation.

Question 68: What is the defining morphological feature that distinguishes the maxillary lateral incisor from the maxillary central incisor?

It has no cingulum
It has two roots
It is smaller and more variable in shape with a more rounded incisal edge (Correct answer)
It is larger in all dimensions

Correct answer: It is smaller and more variable in shape with a more rounded incisal edge

The maxillary lateral incisor is smaller and more variable in form than the central incisor, with a more rounded incisal edge and narrower mesiodistal width.

Question 69: Which polymerization mechanism is responsible for the setting of chemically activated (self-cure) acrylic resin?

Anionic polymerization at room temperature
Condensation polymerization releasing water as a by-product
Free-radical addition polymerization initiated by a redox reaction (Correct answer)
Cationic polymerization triggered by UV light

Correct answer: Free-radical addition polymerization initiated by a redox reaction

Self-cure acrylics use a redox initiator system (benzoyl peroxide + amine) to generate free radicals that drive addition polymerization at room temperature.

Question 70: Why are dental impressions important for appliance fabrication?

To capture detailed anatomical information for appliances (Correct answer)
To check for tooth decay.
To test gum health.
To determine tooth color.

Correct answer: To capture detailed anatomical information for appliances

Dental impressions are vital for appliance fabrication because they capture a precise negative mold of the patient's oral structures, including teeth, gums, and surrounding tissues. This detailed anatomical information is indispensable for creating custom-fit dental appliances such as crowns, bridges, dentures, and orthodontic devices. Accurate impressions ensure that the final appliances are precise, functional, and comfortable for the patient.

Question 71: Which firing stage in porcelain condensation produces the greatest shrinkage?

Glaze firing
Wash bake
Body/dentin firing (Correct answer)
Opaque firing

Correct answer: Body/dentin firing

Body/dentin firing involves the largest volume of porcelain and therefore produces the most significant shrinkage during sintering.

Question 72: What is the developmental groove that separates the mesiobuccal and distobuccal cusps on the mandibular first molar called?

Buccal groove (Correct answer)
Distobuccal groove
Central groove
Transverse groove

Correct answer: Buccal groove

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

Question 73: What is the function of opaque porcelain in a porcelain-fused-to-metal (PFM) restoration?

To provide the final surface characterization of the crown
To mask the dark metal coping and bond to the alloy oxide layer (Correct answer)
To create translucency and depth for natural appearance
To act as a thermal insulator between metal and body porcelain

Correct answer: To mask the dark metal coping and bond to the alloy oxide layer

Opaque porcelain masks the dark metal coping and chemically bonds to the oxide layer on the alloy surface, establishing the ceramic-metal bond.

Question 74: Flasking a denture wax-up for compression molding requires separating the flask halves at the:

Height of contour of the wax denture flange (Correct answer)
Occlusal surface of posterior teeth
Cervical margin of the artificial teeth
Level of the master cast land area

Correct answer: Height of contour of the wax denture flange

The flask is separated at the height of contour of the wax flange so both halves can be opened without trapping undercuts in the stone investment.

Question 75: What role does documentation play in dental anatomy & morphology?

It is only necessary when problems arise
It is primarily a bureaucratic requirement with limited practical value
It replaces the need for direct supervision
It creates accountability, enables quality tracking, and supports continuous improvement (Correct answer)

Correct answer: It creates accountability, enables quality tracking, and supports continuous improvement

Documentation creates accountability, enables quality tracking over time, and provides the data needed for continuous improvement of practices and outcomes.

Question 76: Which file format is the industry standard for sharing digital impression data between scanners and milling software?

SVG (Scalable Vector Graphics)
DXF (Drawing Exchange Format)
STL (Standard Tessellation Language) (Correct answer)
PDF (Portable Document Format)

Correct answer: STL (Standard Tessellation Language)

STL is the most widely accepted open format for sharing 3D scan data across CAD/CAM systems.

Question 77: Under FDA oversight, what distinguishes a 'medical device report' (MDR) from a routine customer complaint in a dental lab?

MDRs replace the need for internal complaint investigation
MDRs are only filed for cases costing more than $1,000
MDRs are required when a device malfunction could cause or contribute to serious injury or death (Correct answer)
MDRs are submitted to the ADA, not the FDA

Correct answer: MDRs are required when a device malfunction could cause or contribute to serious injury or death

MDRs are mandatory reports to the FDA when a device malfunction could cause or contribute to a serious injury or death if it were to recur.

Question 78: Which investment material is used for casting high-fusing noble and base metal alloys due to its ability to withstand higher burnout temperatures?

Phosphate-bonded investment (Correct answer)
Plaster-bonded investment
Gypsum-bonded investment
Silica-bonded investment

Correct answer: Phosphate-bonded investment

Phosphate-bonded investments tolerate burnout temperatures above 700°C, necessary for high-fusing metal alloys used in crowns and bridges.

Question 79: What causes a 'chipping' or delamination failure in a PFM restoration?

Excessive metal thickness
Over-glazing the surface
Using high-fusing porcelain on a low-fusing alloy (Correct answer)
Inadequate bond between opaque and body porcelain

Correct answer: Using high-fusing porcelain on a low-fusing alloy

Using high-fusing porcelain on a low-fusing alloy creates thermal expansion mismatches that result in cohesive or adhesive failures.

Question 80: When constructing a partial denture framework, which survey line determines the path of insertion?

The height of contour line on the buccal surface only
The gingival margin of each abutment tooth
The occlusal rest seat outline form
The survey line established at the chosen path of insertion angle by the surveyor (Correct answer)

Correct answer: The survey line established at the chosen path of insertion angle by the surveyor

The surveyor draws a line at the greatest convexity of each abutment tooth for the selected tilt, defining retentive and reciprocal clasp arm positions.

Question 81: What role does documentation play in dental materials science?

It creates accountability, enables quality tracking, and supports continuous improvement (Correct answer)
It replaces the need for direct supervision
It is only necessary when problems arise
It is primarily a bureaucratic requirement with limited practical value

Correct answer: It creates accountability, enables quality tracking, and supports continuous improvement

Documentation creates accountability, enables quality tracking over time, and provides the data needed for continuous improvement of practices and outcomes.

Question 82: What causes porcelain to appear 'gray' or 'flat' after firing in a PFM crown?

Over-firing the glaze stage
Insufficient opaque coverage allowing metal to show through (Correct answer)
Using too much incisal powder
Incorrect condensation technique

Correct answer: Insufficient opaque coverage allowing metal to show through

Inadequate opaque coverage allows the dark metal substrate to show through, graying out the overlying porcelain.

Question 83: Which permanent tooth has the longest root in the entire dentition?

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

Correct answer: Maxillary canine

The maxillary canine has the longest root of any tooth in the permanent dentition.

Question 84: When processing a complete denture using the compression molding (pack-and-press) technique, a trial closure is performed to:

Check for even distribution of acrylic and close flash lines (Correct answer)
Test the final shade of the denture teeth
Verify the wax is fully eliminated before packing resin
Determine the final vertical dimension of occlusion

Correct answer: Check for even distribution of acrylic and close flash lines

Trial closures confirm even resin distribution throughout the mold and allow excess material (flash) to be trimmed before the final press and processing.

Question 85: What type of eye protection is required when using ultrasonic cleaners to clean dental prostheses?

Face shield alone
No eye protection needed since the tank is sealed
Safety glasses with side shields or goggles (Correct answer)
Standard eyeglasses are sufficient

Correct answer: Safety glasses with side shields or goggles

Safety glasses with side shields or goggles protect against aerosolized contaminated fluid that may be released when opening ultrasonic cleaner tanks.

Question 86: In permanent dentition, which tooth has the longest root relative to crown length?

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

Correct answer: Maxillary canine

The maxillary canine has the longest root of any tooth in the permanent dentition, contributing to its stability and anchorage value.

Question 87: Which metal is commonly used in dental casting alloys?

Aluminum.
Lead.
Cobalt-chromium (Correct answer)
Iron.

Correct answer: Cobalt-chromium

Cobalt-chromium alloys are extensively used in dentistry for casting partial denture frameworks and certain types of crowns. These alloys are favored for their excellent strength, rigidity, and superior corrosion resistance, making them highly durable and long-lasting. They are also biocompatible, providing a reliable and stable foundation for dental prosthetics.

Question 88: Which type of ceramic is most commonly used for full-contour posterior restorations due to its strength and wear resistance?

Leucite-reinforced glass ceramic
Lithium disilicate
Zirconia (Correct answer)
Feldspathic porcelain

Correct answer: Zirconia

Zirconia offers the highest flexural strength among dental ceramics, making it ideal for full-contour posterior crowns and bridges.

Question 89: Galvanic corrosion in the mouth most likely occurs when:

A porcelain surface contacts a metal surface
Dissimilar alloys with different electrochemical potentials contact each other in saliva (Correct answer)
Two identical alloys are in close proximity
High-noble alloys are polished to a high luster

Correct answer: Dissimilar alloys with different electrochemical potentials contact each other in saliva

When dissimilar metals touch in an electrolyte like saliva, current flows from the anodic metal to the cathodic metal, causing the anode to corrode.

Question 90: A lower lingual arch space maintainer is soldered to which tooth type to maintain arch length after premature primary tooth loss?

Mandibular first premolars
Mandibular first or second permanent molars (Correct answer)
Mandibular canines
Mandibular central incisors

Correct answer: Mandibular first or second permanent molars

The lower lingual arch is soldered to bands on the mandibular first or second permanent molars, which serve as stable anchor teeth to prevent mesial drift.

Question 91: Which chemical is commonly used in the dental laboratory for model disinfection but is corrosive to metal and must be used with adequate ventilation?

Sodium hypochlorite (bleach) (Correct answer)
Benzalkonium chloride
Chlorhexidine gluconate
Phenolic compounds

Correct answer: Sodium hypochlorite (bleach)

Sodium hypochlorite is an effective and inexpensive disinfectant but is corrosive to metals, produces irritating fumes, and requires adequate ventilation during use.

Question 92: Which element of risk management, as defined by ISO 14971, involves estimating the probability and severity of potential harms from a dental prosthetic?

Risk estimation (Correct answer)
Risk evaluation
Risk control
Residual risk assessment

Correct answer: Risk estimation

Risk estimation involves determining the probability of occurrence of harm and its severity to quantify the risk associated with a hazardous situation.

Question 93: Which surface treatment increases the bond strength of the resin cement to a zirconia abutment or framework?

Etching with hydrofluoric acid
Airborne-particle abrasion (sandblasting) followed by MDP-containing primer (Correct answer)
Polishing with diamond paste
Steam cleaning only

Correct answer: Airborne-particle abrasion (sandblasting) followed by MDP-containing primer

Airborne-particle abrasion creates micromechanical retention and MDP-containing primers (e.g., Clearfil Ceramic Primer) provide chemical adhesion to zirconia.

Question 94: What is the primary objective of implant prosthetics techniques in Certified Dental Technicians practice?

Reducing the cost of operations
Eliminating the need for ongoing training
Meeting only the minimum regulatory requirements
Ensuring consistent quality and adherence to professional standards (Correct answer)

Correct answer: Ensuring consistent quality and adherence to professional standards

The primary objective of implant prosthetics techniques is ensuring consistent quality and adherence to professional standards that protect both practitioners and those they serve.

Question 95: When receiving a dental impression from a clinical office, what is the FIRST action a dental technician should take?

Remove visible debris with running water
Contact the dentist to confirm the shade
Pour the impression immediately to preserve detail
Disinfect the impression before beginning work (Correct answer)

Correct answer: Disinfect the impression before beginning work

All incoming cases should be disinfected upon receipt before any laboratory work begins, regardless of whether the clinical office claims to have already disinfected them.

Question 96: Which type of gypsum product has the highest compressive strength and is used for die fabrication?

Dental stone
Plaster of Paris
Orthodontic plaster
Die stone (Type IV) (Correct answer)

Correct answer: Die stone (Type IV)

Type IV die stone has the highest compressive strength among gypsum products, making it ideal for accurate die fabrication.

Question 97: Which finishing technique is used to create surface texture on ceramic restorations that mimics natural enamel?

Characterization with porcelain texturing stones and polishing (Correct answer)
Sandblasting with 50-micron alumina
Grinding with a coarse diamond bur
Selective glazing with stains

Correct answer: Characterization with porcelain texturing stones and polishing

Texturing stones and rubber polishing points are used to create perikymata, stippling, and other natural enamel surface features before glazing.

Question 98: When articulating a patient's edentulous casts for complete denture fabrication, a facebow transfer is used to:

Select the appropriate posterior tooth mold
Determine the amount of vertical overlap needed for anterior teeth
Record centric relation between upper and lower ridges
Relate the maxillary cast to the axis of condylar rotation on the articulator (Correct answer)

Correct answer: Relate the maxillary cast to the axis of condylar rotation on the articulator

The facebow records the spatial relationship of the maxillary arch to the transverse hinge axis, allowing accurate mounting of the upper cast on the articulator.

Question 99: Which implant framework material offers the highest flexural strength and is most resistant to fracture in long-span implant bridges?

Porcelain-fused-to-metal (PFM) with non-precious alloy
PMMA (acrylic)
Composite resin
Monolithic zirconia (5Y-PSZ) (Correct answer)

Correct answer: Monolithic zirconia (5Y-PSZ)

5Y-PSZ (cubic/tetragonal zirconia) offers flexural strength exceeding 1,000 MPa, making it highly resistant to fracture in long-span implant-supported bridges.

Question 100: Which federal agency establishes regulations for the disposal of biomedical waste generated in dental laboratories?

FDA Center for Devices
CDC Division of Healthcare Quality Promotion
OSHA at the federal level, with state agencies having primary enforcement authority (Correct answer)
EPA exclusively

Correct answer: OSHA at the federal level, with state agencies having primary enforcement authority

OSHA's Bloodborne Pathogens Standard governs regulated waste at the federal level, but individual states typically have their own biomedical waste regulations that take precedence.

Question 101: In orthodontic band fabrication, after the band is adapted and sized on the tooth model, it is then processed through which step to achieve final adaptation?

Heat treating at 450°C for 30 minutes
Electropolishing in acid bath
Burnishing with a ball burnisher to closely fit all contours (Correct answer)
Sandblasting the inner surface

Correct answer: Burnishing with a ball burnisher to closely fit all contours

Burnishing presses the band material tightly against all tooth contours, ensuring intimate fit that improves cementation retention and marginal seal.

Question 102: What is the main advantage of using porcelain for dental crowns?

High flexibility.
Extreme toughness.
Easy reshaping after cementation.
Superior aesthetics and translucency (Correct answer)

Correct answer: Superior aesthetics and translucency

Porcelain is highly valued in dentistry for its exceptional aesthetic qualities and translucency, allowing it to closely mimic the natural appearance of tooth enamel. This makes porcelain crowns virtually indistinguishable from natural teeth, especially in visible areas of the mouth. While other materials offer strength, porcelain excels in providing a lifelike and aesthetically pleasing restoration.

Question 103: The 'dental formula' for the permanent human dentition is best expressed as:

I 2/2, C 1/1, P 2/2, M 3/3 = 32 teeth total (Correct answer)
I 3/3, C 1/1, P 2/2, M 2/2 = 32 teeth total
I 2/2, C 1/1, P 3/3, M 2/2 = 32 teeth total
I 2/2, C 1/1, P 2/2, M 2/2 = 28 teeth total per arch

Correct answer: I 2/2, C 1/1, P 2/2, M 3/3 = 32 teeth total

The permanent human dental formula is I 2/2, C 1/1, P 2/2, M 3/3, yielding 8 teeth per quadrant and 32 total.

Question 104: When staining and glazing a monolithic zirconia crown in the lab, what is the purpose of the glaze firing?

To create a smooth, glass-like surface that reduces wear on opposing teeth (Correct answer)
To increase the strength of zirconia by 50%
To convert the tetragonal phase to the monoclinic phase
To bond the zirconia to the implant abutment

Correct answer: To create a smooth, glass-like surface that reduces wear on opposing teeth

Glazing fills surface micro-irregularities, producing a smooth surface that minimizes abrasion of the opposing natural dentition.

Question 105: The Shore A hardness scale is most commonly used to measure the hardness of:

Dental ceramics
Acrylic denture bases
Elastomeric impression materials (Correct answer)
Cast metal alloys

Correct answer: Elastomeric impression materials

Shore A hardness is appropriate for soft, flexible materials like elastomeric impression materials (silicones, polyethers).

Question 106: Why is proper ventilation important in the dental lab?

To improve air quality by removing hazardous fumes (Correct answer)
To create noise.
To heat the room.
To increase humidity.

Correct answer: To improve air quality by removing hazardous fumes

Dental labs frequently use materials and chemicals that can release hazardous fumes, dust, and aerosols into the air. Proper ventilation systems are essential to capture and remove these airborne contaminants, thereby improving air quality. This protects dental technicians from respiratory issues and other health problems associated with prolonged exposure to harmful substances.

Question 107: What is the purpose of degassing (oxidizing) a metal coping before porcelain application?

To remove surface oxides that prevent porcelain bonding
To create a controlled oxide layer that promotes porcelain adhesion (Correct answer)
To increase metal hardness
To reduce the melting point of the alloy

Correct answer: To create a controlled oxide layer that promotes porcelain adhesion

Degassing creates a controlled, thin oxide layer on the metal surface that chemically bonds with the opaque porcelain.

Question 108: What is the primary purpose of a face-bow transfer in dental prosthetics?

To determine the incisal guidance angle
To measure the vertical dimension of occlusion
To relate the maxillary cast to the hinge axis of the articulator (Correct answer)
To record the patient's bite registration in wax

Correct answer: To relate the maxillary cast to the hinge axis of the articulator

A face-bow transfer records the spatial relationship of the maxillary arch to the temporomandibular joint hinge axis so the upper cast can be correctly mounted on the articulator.

Question 109: A coffin spring incorporated into the midline of a removable upper appliance is designed to produce which type of arch development?

Transverse (lateral) expansion of the maxillary arch (Correct answer)
Retraction of the anterior segment
Vertical eruption of posterior teeth
Sagittal (anteroposterior) expansion

Correct answer: Transverse (lateral) expansion of the maxillary arch

The coffin spring is a large omega-shaped wire loop placed at the midline of the baseplate that, when activated, pushes the two halves of the appliance apart to widen the upper arch.

Question 110: What is 'centric relation' in the context of complete denture fabrication?

The position recorded when the patient swallows
The most retruded, unstrained position of the mandibular condyles in the fossae (Correct answer)
The rest position of the mandible
The position of maximum intercuspation of the denture teeth

Correct answer: The most retruded, unstrained position of the mandibular condyles in the fossae

Centric relation is a reproducible, bone-supported jaw position used to set complete denture teeth when no natural teeth guide occlusion.

Question 111: Which technique is used to characterize the internal structure of a ceramic crown for a more lifelike appearance?

Single-layer pressing and staining only
Layering technique with dentin, enamel, and effect powders (Correct answer)
Glazing with a tinted glaze paste
Sandblasting with alumina oxide

Correct answer: Layering technique with dentin, enamel, and effect powders

The layering technique uses multiple porcelain powders (dentin, enamel, incisal, effects) to replicate natural tooth structure.

Question 112: Which type of respirator is required when grinding or trimming dental alloys that contain beryllium?

P100 half-face respirator (Correct answer)
N95 filtering facepiece respirator
Powered air-purifying respirator with HEPA filter
Surgical mask

Correct answer: P100 half-face respirator

Beryllium-containing alloys require a P100-rated respirator due to the extreme toxicity and carcinogenicity of beryllium dust particles.

Question 113: Which alloy is most commonly used for cast RPD frameworks due to its favorable combination of stiffness, strength, and biocompatibility?

Nickel-titanium alloy
Cobalt-chromium alloy (Correct answer)
Type IV gold alloy
Titanium alloy

Correct answer: Cobalt-chromium alloy

Cobalt-chromium alloys are the standard for RPD frameworks because they provide high rigidity (important for connectors), strength, corrosion resistance, and lower cost than gold.

Question 114: What term describes the angle formed at the junction of two crown surfaces at the incisal edge?

Axial angle
Incisal angle (Correct answer)
Line angle
Point angle

Correct answer: Incisal angle

Incisal angles are the angles formed at the corners of the incisal edge where the mesial or distal surface meets the labial or lingual surface.

Question 115: What role does documentation play in implant prosthetics techniques?

It is primarily a bureaucratic requirement with limited practical value
It is only necessary when problems arise
It creates accountability, enables quality tracking, and supports continuous improvement (Correct answer)
It replaces the need for direct supervision

Correct answer: It creates accountability, enables quality tracking, and supports continuous improvement

Documentation creates accountability, enables quality tracking over time, and provides the data needed for continuous improvement of practices and outcomes.

Question 116: A zirconia abutment is being fabricated for an anterior implant. Which consideration is MOST critical for long-term success?

Ensuring the abutment is at least 5 mm in height
Avoiding any surface treatment of the zirconia
Keeping the margin supragingival
Using a titanium base (Ti-base) to interface with the implant (Correct answer)

Correct answer: Using a titanium base (Ti-base) to interface with the implant

A titanium base (Ti-base) provides a reliable metal-to-metal connection at the implant interface, while the zirconia overlayer achieves esthetics without compromising strength at the critical junction.

Question 117: Which type of validation is required when a dental lab introduces a new CAD/CAM milling process for producing zirconia copings?

Performance qualification only
No validation is required for digital processes
Installation qualification (IQ) only
IQ, operational qualification (OQ), and performance qualification (PQ) (Correct answer)

Correct answer: IQ, operational qualification (OQ), and performance qualification (PQ)

A complete validation protocol for new manufacturing processes requires IQ, OQ, and PQ to confirm that equipment is installed correctly, operates within parameters, and consistently produces conforming products.

Question 118: When milling zirconia, which milling stage requires the material to be in its pre-sintered (soft) state?

Glazing and staining stage
Green-state milling before sintering (Correct answer)
Post-sintering milling only
Hot isostatic pressing stage

Correct answer: Green-state milling before sintering

Pre-sintered (green-state) zirconia is milled before the final sintering cycle that shrinks and densifies the material.

Question 119: In lost-wax casting, the spruing technique affects which of the following?

Metal flow direction and potential porosity sites (Correct answer)
Alloy hardness after solidification
Shade selection of the final restoration
Investment expansion coefficient

Correct answer: Metal flow direction and potential porosity sites

Sprue placement determines the path of metal entry, and improper design can cause turbulence, back-pressure porosity, or incomplete fill.

Question 120: Which type of pontic design is most hygienic and easiest to clean, making it ideal for long-span bridges in posterior regions?

Ridge-lap pontic
Sanitary (hygienic) pontic (Correct answer)
Modified ridge-lap pontic
Ovate pontic

Correct answer: Sanitary (hygienic) pontic

The sanitary (hygienic) pontic has a convex tissue surface that does not contact the ridge, allowing easy cleaning underneath and reducing plaque accumulation.

Question 121: Why is investment material used in the casting process?

To reduce metal weight.
To create a heat-resistant mold for metal casting (Correct answer)
To polish restorations.
To cool down castings quickly.

Correct answer: To create a heat-resistant mold for metal casting

Investment material is a specialized refractory material that surrounds the wax pattern during the casting process. Its primary function is to create a strong, heat-resistant mold capable of withstanding the extreme temperatures of the burnout process and the subsequent injection of molten metal. This ensures the mold maintains its integrity and shape, allowing for an accurate and precise metal casting that replicates the original wax pattern.

Question 122: Which surface of the mandibular first molar contains the distal pit?

Occlusal surface near the distal marginal ridge (Correct answer)
Buccal surface at the occlusal third
Lingual surface distally
Distal surface at the cervical third

Correct answer: Occlusal surface near the distal marginal ridge

The distal pit of the mandibular first molar is located on the occlusal surface adjacent to the distal marginal ridge.

Question 123: What is the function of an 'enamel' or 'incisal' porcelain in a layered ceramic build-up?

To bond the porcelain to the metal coping
To add translucency and depth to the outer surface, mimicking natural enamel (Correct answer)
To provide the opaque foundation layer
To strengthen the internal core of the restoration

Correct answer: To add translucency and depth to the outer surface, mimicking natural enamel

Incisal/enamel powders are highly translucent and simulate the natural optical depth and light-scattering of tooth enamel.

Question 124: Centric relation in edentulous patients is recorded to:

Determine the shade of artificial teeth
Establish a repeatable jaw relationship for mounting casts (Correct answer)
Measure the width of the residual ridge
Select the denture base color

Correct answer: Establish a repeatable jaw relationship for mounting casts

Centric relation provides a reproducible mandibular position from which vertical dimension and occlusion can be accurately established on an articulator.

Question 125: A stress-breaker in a removable partial denture framework is used to:

Provide additional indirect retention
Improve esthetics of the prosthesis
Increase the rigidity of the major connector
Reduce forces transmitted to abutment teeth (Correct answer)

Correct answer: Reduce forces transmitted to abutment teeth

Stress-breakers (stress relievers) introduce a flexible joint that reduces harmful torquing forces transferred to abutment teeth during function.

Question 126: Which material is used to invest wire components before processing acrylic for a removable appliance to protect them from displacement?

Alginate
Zinc phosphate cement
Sticky wax and baseplate wax (Correct answer)
Plaster of Paris slurry

Correct answer: Sticky wax and baseplate wax

Sticky wax and baseplate wax are used to secure wire components to the model in their correct positions so they remain stable when the acrylic dough is applied.

Question 127: The 'altered cast' technique for distal extension RPDs is used to:

Re-record the opposing arch after tooth loss
Reduce the vertical dimension before framework try-in
Survey the master cast at a different tilt angle
Obtain an accurate functional impression of the extension base area under load (Correct answer)

Correct answer: Obtain an accurate functional impression of the extension base area under load

The altered cast technique replaces the edentulous ridge portion of the master cast with a functional impression taken through the seated framework, recording tissue under functional load.

Question 128: In occlusion terminology, what is the working side?

The posterior region of the arch during protrusion
The non-functional side opposite the direction of chewing
The side where balancing contacts are located
The side toward which the mandible moves during lateral excursion (Correct answer)

Correct answer: The side toward which the mandible moves during lateral excursion

The working side (also called the laterotrusive or functioning side) is the side toward which the mandible moves during lateral excursion.

Question 129: Which milling parameter most directly affects the surface roughness of a milled ceramic restoration?

Stepover distance between toolpaths (Correct answer)
Color of the milling blank
Spindle cooling water temperature
CAD file polygon count only

Correct answer: Stepover distance between toolpaths

A smaller stepover distance between adjacent toolpaths produces a smoother surface by reducing the scallop height.

Question 130: Which competency is most essential for professionals working in implant prosthetics techniques?

Comprehensive knowledge combined with practical application skills (Correct answer)
Theoretical knowledge alone without hands-on experience
Basic awareness of the topic from general reading
Familiarity only with the most common scenarios

Correct answer: Comprehensive knowledge combined with practical application skills

Effective practice requires both comprehensive knowledge and practical application skills, as theory alone cannot address real-world challenges.

Question 131: Why is stakeholder communication important in crown & bridge fabrication?

It is only needed when major changes are being implemented
It is only relevant for management-level positions
It slows down the implementation process unnecessarily
It ensures alignment of expectations and facilitates collaborative decision-making (Correct answer)

Correct answer: It ensures alignment of expectations and facilitates collaborative decision-making

Stakeholder communication ensures everyone involved has aligned expectations and can contribute to informed, collaborative decision-making.

Question 132: What does 'value' refer to in the Vita shade system?

The translucency level of the porcelain
The chroma or saturation of the color
The hue or color family of the tooth
The lightness or darkness of the shade (Correct answer)

Correct answer: The lightness or darkness of the shade

Value describes the relative lightness or darkness of a shade, ranging from very light (high value) to very dark (low value).

Question 133: How long must OSHA-required training records for bloodborne pathogen exposure control be retained?

3 years (Correct answer)
5 years
10 years
1 year

Correct answer: 3 years

OSHA requires that bloodborne pathogen training records be maintained for 3 years from the date of training.

Question 134: What is the primary advantage of using addition-cured silicone (VPS) impression materials over condensation silicones?

Lower cost
Better hydrophilicity in wet fields
Dimensional stability with minimal shrinkage (Correct answer)
Faster setting time

Correct answer: Dimensional stability with minimal shrinkage

Addition-cured silicones (VPS) produce no by-products during polymerization, resulting in excellent dimensional stability and minimal shrinkage.

Question 135: When addressing challenges in orthodontic appliance construction, what approach is most effective?

Systematic analysis of root causes followed by evidence-based solutions (Correct answer)
Quick fixes that address only the immediate symptoms
Applying the same solution regardless of the specific challenge
Waiting for problems to resolve on their own

Correct answer: Systematic analysis of root causes followed by evidence-based solutions

Systematic root cause analysis with evidence-based solutions addresses problems at their source, preventing recurrence and leading to lasting improvement.

Question 136: The oblique ridge is a landmark unique to which tooth?

Mandibular first premolar
Mandibular second molar
Maxillary first premolar
Maxillary first molar (Correct answer)

Correct answer: Maxillary first molar

The oblique ridge of the maxillary first molar runs diagonally across the occlusal surface from the distobuccal cusp to the mesiolingual cusp.

Question 137: Which hardener is commonly added to acrylic resin to improve its cross-link density and reduce porosity?

Ethylene glycol dimethacrylate (Correct answer)
Zinc oxide
Benzoyl peroxide alone
Methyl methacrylate monomer only

Correct answer: Ethylene glycol dimethacrylate

Cross-linking agents like ethylene glycol dimethacrylate (EGDMA) form bridges between polymer chains, increasing strength and reducing residual monomer.

Question 138: Why is surface disinfection important?

To dry instruments faster.
To help with heating.
To reduce the risk of cross-contamination (Correct answer)
To make surfaces shiny.

Correct answer: To reduce the risk of cross-contamination

Surface disinfection is critical in dental labs and clinics to eliminate or significantly reduce the number of microorganisms on environmental surfaces. By disinfecting surfaces, the risk of transferring pathogens from contaminated areas to patients, dental technicians, or instruments is greatly reduced. This practice is essential for preventing cross-contamination and maintaining a safe and hygienic working environment.

Question 139: What is the purpose of using a dental articulator?

To measure tooth color.
To sterilize dental models.
To harden impression materials.
To simulate jaw movements for accurate restoration alignment (Correct answer)

Correct answer: To simulate jaw movements for accurate restoration alignment

A dental articulator is a mechanical device designed to simulate the movements of a patient's jaw. By mounting dental models on an articulator, technicians can accurately assess and adjust the occlusion (bite) of restorations such as crowns, bridges, or dentures. This ensures that the fabricated appliances fit correctly, function harmoniously with the patient's natural dentition, and prevent occlusal interferences.

Question 140: How does the root trunk length of the maxillary first molar compare to that of the maxillary second molar?

Both have equal root trunk lengths
Root trunk length is not a consistent distinguishing feature
The first molar has a longer root trunk
The second molar has a longer root trunk (Correct answer)

Correct answer: The second molar has a longer root trunk

The maxillary second molar has a longer root trunk (the portion of the root below the CEJ and above the furcation) than the first molar, making furcation access more difficult.

Question 141: What is the coefficient of thermal expansion (CTE), and why is it critical in PFM restorations?

A measure of porcelain translucency used to select shade
The strength rating of dental porcelain; higher is better
A measure of how a material expands/contracts with temperature; metal and ceramic CTEs must be compatible (Correct answer)
The rate at which porcelain sets; it determines firing time

Correct answer: A measure of how a material expands/contracts with temperature; metal and ceramic CTEs must be compatible

CTE compatibility between metal and porcelain prevents internal stresses that would cause cracking or delamination during cooling.

Question 142: Which Angle's classification describes a normal molar relationship (Class I)?

The mesiobuccal cusp of the upper first molar occludes in the buccal groove of the lower first molar (Correct answer)
The upper first molar is entirely lingual to the lower first molar
The mesiobuccal cusp of the upper first molar occludes mesial to the lower first molar buccal groove
The mesiobuccal cusp of the upper first molar occludes distal to the lower first molar buccal groove

Correct answer: The mesiobuccal cusp of the upper first molar occludes in the buccal groove of the lower first molar

Angle's Class I is defined by the mesiobuccal cusp of the maxillary first molar occluding in the buccal groove of the mandibular first molar, representing the ideal molar relationship.

Question 143: Which base metal alloy component is primarily responsible for the natural oxide layer that improves ceramic bonding in PFM restorations?

Platinum
Tungsten
Beryllium or tin (Correct answer)
Molybdenum

Correct answer: Beryllium or tin

Beryllium and tin in base metal alloys form surface oxides during oxidation that chemically bond to porcelain for improved ceramic adhesion.

Question 144: Which of the following best describes the root trunk?

The area of the root where the periodontal ligament attaches
The portion of the root embedded in alveolar bone
The apical portion of each individual root
The undivided portion of the root below the cervical line before furcation (Correct answer)

Correct answer: The undivided portion of the root below the cervical line before furcation

The root trunk is the undivided section of a multi-rooted tooth's root structure that exists between the cervical line and the furcation.

Question 145: When a zirconia coping is sandblasted prior to veneering, the primary purpose is to:

Remove residual sintering contaminants only
Alter the translucency of zirconia
Reduce coping thickness
Improve surface wettability and mechanical bonding for porcelain (Correct answer)

Correct answer: Improve surface wettability and mechanical bonding for porcelain

Sandblasting creates surface roughness on the zirconia coping that improves micromechanical retention and wettability for the veneering porcelain.

Question 146: In canine-protected (mutually protected) articulation, what is the specific role of the canine teeth?

They provide balanced bilateral contacts during all lateral excursions
They provide protrusive guidance but not lateral guidance
They serve as the primary power teeth during heavy chewing
They immediately disclude all posterior teeth during lateral excursion (Correct answer)

Correct answer: They immediately disclude all posterior teeth during lateral excursion

In canine-protected articulation, the canines bear lateral forces and their steep guidance immediately separates all posterior teeth during any lateral excursion, protecting posterior restorations.

Question 147: Epoxy die materials are superior to gypsum dies in which property?

Better dimensional accuracy and abrasion resistance (Correct answer)
Lower cost per unit
Greater ease of trimming and adjustment
Faster setting time

Correct answer: Better dimensional accuracy and abrasion resistance

Epoxy resin dies exhibit very low setting shrinkage, excellent surface hardness, and high abrasion resistance, making them ideal for precision work.

Question 148: What is the gauge range most commonly used for stainless steel wire when fabricating the labial bow of a Hawley retainer?

0.7–0.8 mm (19–21 gauge)
1.0–1.2 mm (17–18 gauge)
0.3–0.4 mm (26–28 gauge)
0.5–0.6 mm (22–24 gauge) (Correct answer)

Correct answer: 0.5–0.6 mm (22–24 gauge)

The labial bow of a Hawley retainer is typically constructed from 0.5–0.6 mm (22–24 gauge) stainless steel wire, balancing flexibility for passive retention with sufficient rigidity.

Question 149: Which feature most readily distinguishes the mandibular right canine from the mandibular left canine when viewed from the labial aspect?

The lingual surface shows a prominent mesial marginal groove
The distal slope of the cusp tip is longer than the mesial slope (Correct answer)
The root curves distally at the apex
The mesial slope of the cusp tip is longer than the distal slope

Correct answer: The distal slope of the cusp tip is longer than the mesial slope

On mandibular canines, the distal cusp slope is longer than the mesial slope, and the root tip curves distally, helping identify right from left.

Question 150: A palatal expander that uses a jackscrew mechanism and is cemented to molar bands is best described as which appliance type?

Bionator
Hawley retainer
Frankel appliance
Rapid Palatal Expander (RPE) (Correct answer)

Correct answer: Rapid Palatal Expander (RPE)

A Rapid Palatal Expander (RPE) uses a midline jackscrew bonded or banded to the molars to apply heavy orthopaedic forces that open the mid-palatal suture.

Question 151: Why is burnout important in the casting process?

To color the final restoration.
To add strength to the wax.
To remove wax and prepare the mold for casting (Correct answer)
To cool the mold.

Correct answer: To remove wax and prepare the mold for casting

Burnout is a critical step in the lost wax casting technique, where the invested wax pattern is heated in a furnace to high temperatures. This process completely vaporizes the wax, leaving a clean, hollow cavity within the investment mold that precisely replicates the original wax pattern. The empty mold is then ready to receive molten metal, ensuring an accurate and contaminant-free casting for the final restoration.

CDT Exam

The CDT Examination certifies dental technicians in specialized areas, demonstrating their expertise in fabricating dental prosthetics and appliances.

150

Questions

180 min

Time Limit

75%

To Pass

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