Effect of Etchant System on Bond Strength of Teeth subjected to Desensitizing Agent Application: An In Vitro study

AIM OF THE STUDY: To evaluate the role of etch-and-rinse and self-etch on bond strength of teeth subjected to gluma desensitizer in office desensitizer and Sensodyne repair and protect (Novamin). METHODOLOGY: A sample of 36 sound freshly extracted human mandibular premolar teeth was selected. The samples were randomly divided into two groups: Group 1 – etch-and-rinse (n=18), Group 2 – self-etch (n=18). Group 1 was further subdivided into 1A - Gluma Desensitizer (Heraeus Kulzer GmbH) (n=6), 1B - Sensodyne Repair and Protect, powered by Novamin (Group Pharmaceuticals Limited,India) (n=6), 1C - control where no desensitizing agents were applied (n=6). Group 2 was similarly subdivided as in group 1.After adhesive procedure, the restored samples (n=30), 5 in each group were selected for mechanical testing and 1 in each group (n=6) was allotted for scanning electron microscope analysis. After microtensile bond strengths, each of the specimens were observed using a microscope (Labomed, Prisma Microscope, USA) under 2.5x magnification to observe the type of fracture (Cohesive / Adhesive). RESULTS: Self-etch group showed significantly greater bond strength when compared to the etch-and-rinse group. But no significant difference was seen among the desensitizer agent groups, Sensodyne paste, Gluma Desensitizer and control group in both the etch-and-rinse and self-etch category. When considering within the groups Sensodyne paste group had higher incidence of adhesive failure when compared to Gluma Desensitizer and control group in self-etch group and etch-and-rinse group but was not significant. Post hoc test depictts no significant difference among between Gluma Desensitizer, Sensodyne paste group and control groups. CONCLUSION: Bond strength increased with self-etch and it performed better when compared to etch-and-rinse along with the desensitizers used and was statistically significant. Higher number of adhesive fractures was seen in Sensodyne Repair and Protect group when compared to Gluma Desensitizer and the control group. When dentin has been treated with desensitizing agents it is preferable to opt for mild self-etching bonding agents