ADC - Australian Dental Council Operative and Restorative Dentistry Questions and Answers — Questions and Answers
Question 1: 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 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)
- A full-coverage gold crown to provide maximum durability.
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 2: 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?
- Placing prophylactic amalgam restorations in all fissures.
- Applying a high-viscosity glass ionomer cement as a fissure sealant. (Correct answer)
- Prescribing a high-fluoride toothpaste (5000 ppm) for daily use.
- Scheduling the patient for a six-month review with no active treatment.
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 3: 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.
- 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)
- Placing retentive grooves in the dentin to prevent dislodgement of the restoration.
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 4: 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 National Health and Medical Research Council (NHMRC)
- The Food and Drug Administration (FDA)
- 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 5: 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?
- Immediate operative intervention with a slot preparation and direct composite.
- Application of a professionally applied high-concentration fluoride varnish and radiographic monitoring. (Correct answer)
- Prescribing an antimicrobial mouthrinse to eliminate cariogenic bacteria.
- 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 6: 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?
- Micro-filled composite resin for superior polishability.
- Dental amalgam for its proven longevity.
- Resin-modified glass ionomer cement (RMGIC) for its adhesion and fluoride release. (Correct answer)
- A full-coverage ceramic veneer for optimal aesthetics.
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.
ADC - Australian Dental Council Operative and Restorative Dentistry Questions and Answers
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?