What is the correct technique for excavating deep caries?

Correct answer: C. A large round bur at slow speed, working from the periphery toward the centre

• A. A small bur concentrates force at a point and readily perforates into the pulp; working outward from the centre attacks the deepest area first.
• B. High speed removes the tactile feedback essential to judging proximity to the pulp.
• C. CORRECT. Two principles combine here. A LARGE ROUND BUR at SLOW SPEED is less likely to plunge through softened dentine into the pulp — its diameter distributes the load and the low speed gives tactile feedback. And working from the PERIPHERY toward the CENTRE removes caries at the enamel-dentine junction first, where the lesion is broadest, while leaving the deepest central dentine — the tissue overlying the pulp horn — until last, when the operator can judge whether to stop short.
• D. Working centre-outward at high speed with a large bur combines the worst features of every option.

Note: In a deep lesion, consider stepwise or selective caries removal: leave a thin layer of affected but remineralisable dentine over the pulp horn, seal it, and avoid the exposure altogether.