Restorative Dentistry and Dental Materials
What the exam tests
Restorative questions test material choice by tooth type, remaining enamel, isolation and pulp status, rather than brand knowledge.
Core rules
- Primary enamel is thin (about 0.5-1 mm), dentin is thin, and pulp horns are high, so caries reaches pulp early.
- Stainless steel crowns are best for multi-surface primary molars, hypoplasia and after pulpotomy. The Hall technique needs no local anaesthetic or prep but relies on glass ionomer cement and careful case selection.
- Anterior primary teeth: strip crown or zirconia; composite needs moisture control; amalgam is not used anteriorly.
- Class I and II in primary teeth: RMGI or composite; compomer in low-stress areas.
- Bonding to primary dentin is weaker than to permanent dentin; follow the manufacturer's etch and avoid contamination.
- Do not restore a tooth with irreversible pulpitis or a sinus tract; treat the pulp or extract.
Worked example
A 5-year-old has a large carious first primary molar with a pulp exposure, no radicular pathology, and 2 mm of sound enamel. Reasoning: the pulp is vital with no pathology, so perform a pulpotomy with MTA or ferric sulfate and place a stainless steel crown. A strip crown would fail on a posterior molar under load, and a composite would leak.
Traps
Using a strip crown on a primary molar; direct pulp capping a large primary exposure; forgetting to check occlusion after an SSC; assuming zirconia is always superior regardless of enamel.