Dentistry

Abstract

The Effect Of Home Bleaching Agents On The Surface Roughness And Fracture Toughness Of Composite Resin Materials

Vishwakarma P, Karale R, Srirekha A, Hegde J, Savitha B and Srinivasan A

Aim and Objective: This study determined the effect of home bleaching agents on the surface roughness and fracture toughness of composite resin materials.
Methodology: 70 specimen of nanohybrid resin composite (Filtex supreme plus (Z 350) and Esthet x) were exposed to two home bleaching gels (10% and 20% carbamide peroxide CP) were prepared. Thirty five specimen of each group were fabricated randomly divided into 6 subgroup as follows: Group 1 Filtex supreme plus (Z 350) (N=35):Subgroup 1 (n=5)-control group (distilled water), subgroup 2 (n=15)-treated with 10% CP, subgroup 3 (n=15)-treated with 20% CP. Group 2 Esthet x (n=35): subgroup 1 (n=5)-control group ( distilled water), subgroup 2 (n=15)-treated with 10% CP, subgroup 3 (n=15)-treated with 20% CP for 8 hrs/day. All treatment was conducted at room temperature and fresh gel applied and rinsed off daily for 2 weeks. For bleached group, the specimens were stored in distilled water during hiatus period. All specimen were subjected to roughness testing (Ra) at 0 day, 1 day and 14th day using the profilometer and then subjected to three point bending test for fracture toughness. Then all the data were send for statistical analysis.
Results: 1) Both nanohybrid composite showed minimal surface roughness values as they are below the critical threshold of 0.2 mm which is not clinically significant. 2) The surface roughness value of Filtex Z350 is lower than Esthet X but not statically significant (p<0.05). 3) Bleaching had a significant effect in increasing the fracture toughness value on Filtek Z350 but not on the Esthet X composite.
Conclusion: Within the limitation of the present study it was concluded that the practice of home bleaching after placement of the composite restoration does not compromise on surface roughness and the fracture toughness property of the resin composites and does not need its replacement.