Effect of Glycerin Application On The Surface of Microhybrid Composite Resin to Its Compressive Strength with Immersed in Pure Coffee Solution

Abstract

ABSTRACT Introduction: There are various restoration materials, one of which is microhybrid composite resin. An effective way to increase its compressive strength is by applying glycerin before curing. This can minimize the formation of a layer of OIL (Oxygen inhibition layer) which is formed due to polymerization that interrupted by the contact of composite resin with oxygen. Exposure with acidic solution such as pure coffee solution causing the occurrence of matrix degradation which can decrease the compressive strength of microhybrid composit. The longer its immersed in pure coffee solution, the more polymer bonds are broken and releasing monomer which result in a decrease of compressive strength. Objective: This study aimed to reveal the effects of glycerin application on the compressive strength of microhybrid composite resins immersed in pure coffee solution. Methods: There are 6 sample groups of composite resin namely: group SG, group S, group GK16, group K16, group GK32, and group K32 with 4 samples per group. Each sample made of microhybrid composite resin brand Filtek Z250 shaped disc with a diameter of 4 mm and thickness of 2 mm. Glycerin was applied to the surfaces of three groups before curing, while other groups were not. After treatment, all samples are compressive strength tested using Universal Testing Machine. The data were analyzed using the Two Way ANOVA followed by Post-Hoc LSD test. Result: The groups with glycerin had higher compressive strength than those groups without glycerin application. The non-immersed groups had a higher hardness level than those groups which were immersed. The Two-Way ANOVA test confirmed that there was a statistically significant difference (p<0.05) among all groups. Conclusion: Glycerin application can increase the compressive strength of microhybrid composite resin immersed in pure coffee solution by minimizing OIL formation on its surface.