Influence of home bleaching regimen on microhardness and flexural strength of two contemporary composite resins – an in vitro evaluation

Authors : Kalaivani MURALİDASAN, Dattaprasad S, Indumathi M, Sruthipriya M, Janani BALACHANDRAN, Pavankumar O

Pages : 90-95

Doi:10.26650/eor.20231083203

View : 26 | Download : 67

Publication Date : 2023-05-31

Article Type : Research Paper

Abstract :Purpose This study was to compare and evaluate the effect of home bleaching on the microhardness and flexural strength of microhybrid and nanohybrid composite resins. Materials and Methods The study samples were prepared using a custom-made silicon rubber mold. For microhardness evaluation, 40 disc-shaped specimens insert ignore into journalissuearticles values(4mm*2mm); were prepared and divided into 4 groups: GROUP A insert ignore into journalissuearticles values(n=10);: microhybrid insert ignore into journalissuearticles values(GC Solaire X, GC Corporation); control group, GROUP B insert ignore into journalissuearticles values(n=10); nanohybrid insert ignore into journalissuearticles values(Tetric N Ceram, Ivoclar Vivadent); control group, GROUP C insert ignore into journalissuearticles values(n=10);: microhybrid bleaching group, GROUP D insert ignore into journalissuearticles values(n=10); nanohybrid bleaching group. For flexural strength evaluation, 40 bar shaped specimens insert ignore into journalissuearticles values(25mm*2mm*2mm); were prepared. They were divided into 4 groups, GROUP 1 insert ignore into journalissuearticles values(n=10);: microhybrid control group, GROUP 2 insert ignore into journalissuearticles values(n=10); nanohybrid control group, GROUP 3 insert ignore into journalissuearticles values(n=10);: microhybrid bleaching group, GROUP 4insert ignore into journalissuearticles values(n=10); nanohybrid bleaching group. All the control groups were placed in artificial saliva and bleaching groups were exposed to home bleaching agent for 14 days according to manufacturer’s instructions. The microhardness and flexural strength were evaluated for the respective specimens after 14 days and the data were statistically analyzed. Results Home bleaching regimen decreased microhardness of both microhybrid and nanohybrid composites whereas there was no significant effect on the flexural strength. Nanohybrid composites showed greater microhardness values before and after bleaching. Conclusion Bleaching agents, irrespective of their concentration can decrease the microhardness of the composite resin samples, which raises a concern about replacement of these restorations due to the effects on physical and mechanical properties.
Keywords : Composite resin, Home bleach, Nanohybrid, Microhardness, Flexural strength