Effect of different tooth whitening systems in combination with buffering and antioxidant agents on the shear bond strength of composite resin – An invitro study

Abstract

Aim: The purpose of this in-vitro study was to evaluate the effect of tooth whitening systems on bond strength of composite resin. Material and Methods:One hundred and twenty maxillary central incisors (n=120) were divided into two groups based on the tooth whitening procedure used. Group 1: Bleaching (Pola Office, USA), Group 2: Micro abrasion (Opalustre, Australia). The samples subdivided into three groups depending on the surface treatments. Group A: Control (no surface treatment), Group B: Buffering agent (Sodium bicarbonate), Group C: buffering agent followed by Antioxidant (Sodium ascorbate). After the surface treatments, the groups were further subdivided into two (I & II), based on the storage period in artificial saliva before the composite restoration.Composite resin was bonded to the labial surface of the teeth perpendicular to the long axis and the specimens were stored in artificial saliva for 24 hours. The samples were then subjected to shear bond strength test under the Universal testing machine. Statistical analysis: The results obtained were subjected to statistical analysis using a two-way ANOVA test, independent t-test, and Tukeys multiple post hoc tests. The p value was set <0.05. Results:The results obtained have shown that out of all the groups, Group 1 with CII showed higher bond strength and Group 1 with AI shower lower values of bond strength. Among the groups, all the groups surface treated with buffering agent and antioxidant showed higher values of bond strength than control and buffering agent groups. The delay in time period showed significant difference in Group 1 than in Group 2. Conclusions: Within the limitations of the current study, bleaching and micro abrasion followed by surface treatment using buffering agent followed by antioxidant application showed improved bond strength than the other groups after bleaching. Key Words: Bleaching, Microabrasion, Buffering agent, Antioxidant, Bond strength.