The efficacy of lining materials in the reduction of microleakage in class II composite resin restoration using the sandwich technique: A stereomicroscopic study.

Background: The sealing ability of different liners under composite restorations in the reduction of microleakage.

Aim: To evaluate the effects of three different liners in sandwich techniques on gingival microleakage of class II composite restorations.

Materials and methods: Standardized Class II box cavities were prepared on forty premolar teeth and randomly divided into four groups, n = 10: Group A, no liner (control); Group B, Polofil NHT Flow; Group C, Ionolux; and Group D, Fuji VII. The etching, bonding, and process for restoring the whole remaining mass of the cavities with G-aenial composite were the same, with the sandwich material expectations. Dye penetration was evaluated using a stereomicroscope.

Statistical analysis: Duncan's Post hoc analysis and Friedman's test.

Results: Group A showed the highest microleakage followed by Group D, Group C, and Group B.

Conclusion: Polofil NHT Flow seems to be a promising liner for gingivally deep class II cavities.