Effect of Cola on Surface Microhardness and Marginal Integrity of Resin Modi- fied Glass Ionomer and Compomer Restoration – An in vitro Study

This study was carried out to evaluate the surface microhardness and marginal integrity of a resin modified glassionomer and a compomer after immersing them in a cola soft drink for variable periods of time. The study was conductedin two parts. Forty two standard class V cavities were prepared on extracted human premolars, restored with Dyract AP andFuji II LC and evaluated for marginal integrity. Forty two circular discs (CDs) were prepared with Dyract AP and Fuji II LCto test microhardness. These specimens were immersed in a cola drink under low, medium and high immersion regimes.Marginal integrity was analyzed using stereomicroscope and surface microhardness was evaluated on the circular discsusing a microhardness tester. Statistical analysis revealed that the marginal integrity was least affected in low and mediumimmersion regimes and highly affected under high immersion regime. Surface microhardness was least affected in lowimmersion regime, while, medium and high immersion regimes showed appreciable softening of both restorative materialsevaluated.