True or false: filled & unfilled sealants penetrate the fissures equally well, and there is no difference in microleakage.

• A. True
• B. False: filled sealants penetrate better
• C. False: unfilled sealants penetrate better
• D. False: there is a difference in microleakage

Answer: (A)

Penetration into fissures and the level of microleakage are driven more by how the sealant is applied than by whether it contains filler. When enamel is properly etched, rinsed, dried, and the fissures are cleaned, both filled and unfilled sealants can wet and flow into the fissure walls effectively. The presence of filler makes the resin more viscous, which could theoretically hinder flow, but with current formulations and proper technique the difference in penetration is not clinically meaningful. Microleakage depends on how well the sealant adapts to the enamel and on polymerization shrinkage; with correct bonding practices and curing, filled and unfilled sealants show comparable marginal seals. So, in routine practice, there isn’t a practical difference in penetration or microleakage between the two, making the statement true.