Restorative & Materials · single question
What is the minimum safety distance you should maintain from the pulp when removing dentin (preparing a cavity)?
Show answer and explanation
Correct answer: B. 2 mm
B) 2 mm — CORRECT.
A minimum of 2 mm of remaining dentin between the preparation floor and the pulp is considered the safe zone to prevent inadvertent pulp exposure and thermal/chemical insult to the pulp. Below 2 mm, a calcium hydroxide liner or glass ionomer base should be considered as a pulp protection measure. Below 0.5 mm, direct pulp capping may be needed even without exposure.
A) 1 mm: Too thin — significant pulpal compromise risk at this distance.
C) 3 mm: Safe but more conservative than the minimum requirement; not the stated minimum.
D) 5 mm: Overly conservative — would limit the depth of legitimate preparations.
A minimum of 2 mm of remaining dentin between the preparation floor and the pulp is considered the safe zone to prevent inadvertent pulp exposure and thermal/chemical insult to the pulp. Below 2 mm, a calcium hydroxide liner or glass ionomer base should be considered as a pulp protection measure. Below 0.5 mm, direct pulp capping may be needed even without exposure.
A) 1 mm: Too thin — significant pulpal compromise risk at this distance.
C) 3 mm: Safe but more conservative than the minimum requirement; not the stated minimum.
D) 5 mm: Overly conservative — would limit the depth of legitimate preparations.
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