Comparative evaluation of shear bond strength of different bonding system with effect of saliva contamination and decontamination. - An in vitro study

Introduction: This study aims for the bond strength measurement of two new self etch bonding agent and effect of salivary contamination and decontamination on the bonding agent strength. Materials and Methods:Premolar teeth, 60, removed during orthodontic treatment were collected and the buccal surfaces of the tooth were made to a plane dentinal surface. The randomly divided samples were distributed into three subgroups for OptibondAll in one kerr (BSA) and three subgroup for Single Bond Universal 3M (BSB) of 10 each. For optibond all in one (BSA), BSA-I Is the control group (self-etch bonding agent applied to flat dentine), BSA-II Is the contamination group (self-etch bonding agent applied, followed by saliva application and then dried with air), BSA-III Is the decontamination group (application of self-etch bonding agent, followed by contamination of saliva, dried with air and then reapplication of self-etch bonding agent). For Single Bond Universal 3M(BSB), BSB-I - The control group (self-etch bonding agent applied to flat dentine), BSB-II -The contamination group (self-etch bonding agent applied, followed by saliva application and then dried with air), BSB-III -The decontamination group (application of self-etch bonding agent, followed by contamination of saliva, dried with air and then reapplication of self-etch bonding agent). Followed by the bonding procedure, a 5mm composite block with bulkfill (ivoclar vivadent) was built on the flat dentine surface. Instron universal testing machine (USA) with a 1 mm per minute cross head speed was used to test the bonding strength. Data Obtained were subjected to statistical analysis by one way ANOVA test, and tukey's multipe comparison and unpaired t-test for the inter group comparison. Result: In the Kerr group (BSA), the shear bond strength of the contamination sub-group (BSA-II) decreased to 5.57 ± 1.77 MPa, as opposed to 13.87 ± 2.12 MPa of control group (BSA-I) and 14.85 ± 2.25 MPa of BSA-III group, which was significant statistically. The bond strength of BSA-I (control group) and BSA-III (decontamination group) showed no significant difference. In 3M Universal group (BSB) bond strength significantly decreased in BSB-II (contamination group) 3.72 ± 1.29 MPa when compared to BSB-I (control group) 5.62 ± 0.53 MPa and BSB-III (decontamination group) 9.86 ± 1.09 MPa, which was significant statistically. The bond strength of BSB-III, wherein 3M universal bond was reapplied after contamination of saliva was found to be significant statistically than BSB-I and BSB-II. Conclusion: Both the self etch system, Optibond All in one kerr and Single Bond Universal 3M showed reduction in dentine bond strength when Contamination by saliva was done during restorative procedure. Reapplication of the bonding agent for the kerr Optibond All in one and 3M Single Bond Universal can recover the bond strength after air drying off the saliva over the dentine surface. In 3M Single Bond Universal group, added application of bonding agent improved bond strength significantly after saliva decontamination.