A carious lesion is completely sealed beneath a pit-and-fissure sealant. What is the most likely outcome?

Correct answer: A. The lesion arrests

• A. CORRECT. Sealing a lesion deprives the bacteria of their SUBSTRATE. Fermentable carbohydrate can no longer reach them, so acid production ceases, the bacterial population declines dramatically, and the lesion ARRESTS. This has been demonstrated repeatedly and is the basis for sealing over questionable occlusal surfaces rather than opening them up to investigate.
• B. A properly placed, intact and monitored sealant does not leak sufficiently to sustain the lesion.
• C. The opposite occurs — without dietary substrate the organisms cannot continue to produce acid.
• D. Discolouration is not the outcome, and the lesion is very much affected.

Note: This underpins minimally invasive dentistry: sealing a doubtful fissure is more conservative and often more effective than exploratory preparation, which converts a questionable surface into a permanent restoration cycle.