Abstract
•Pre-application of Viscostat and Expasyl on dentin conditioned with PDT improved bond integrity.•Viscostat and Expasyl result in conceded bond integrity of composite to dentin in etch and rinse and self-etch group.•The majority of failure type was adhesive among experimental groups.
The present study was undertaken to evaluate the influence of gingival retraction agents (Expasyl and Viscostat) and different conditioning methods (Total-etch, Self-etch, and PDT) on bond integrity of composite to dentin.
One hundred and eighty, third molars were collected cleaned and disinfected in thymol solution. The specimens were rooted vertically up to cementoenamel junction within polyvinyl cylinders (PVC). Based on gingival retraction materials samples were divided into three groups (n = 60). Group A: dentin applied with Expasyl; Group B: Viscostat was applied on dentin and Group C: Control. Dentin surface was treated with different surface conditioners. Etch and rinse, PDT MBP, and Two-step self-etch. A bonding agent was applied and composite buildup was done. Samples were placed in the universal testing machine for SBS. Bond failure was assessed using a stereomicroscope. Analysis of variance (ANOVA) and Tukey's post hoc test compared the means and standard deviations (SD) after SBS testing (p = 0.05).
The highest score of bond strength was exhibited by group C1 (21.14 ± 1.05 MPa-Etch & rinse + Tetric-N- Bond) whereas group C2 (12.15 ± 0.28 -PDT MBPS + Tetric-N-Bond, No treatment group) demonstrated the lowest SBS. Based on the application of haemostatic agent, bond values among subgroups A1 (18.75 ± 1.05 MPa - Expasyl + Etch & rinse + Tetric-N-bond) and B1 (17.84 ± 0.11 MPa -Viscostat + Etch & rinse + Tetric-N-Bond) was comparable (p>0.05). Based on the conditioning methods, bond scores among groups C1 (21.14 ± 1.05 MPa -Etch & rinse + Tetric-N- Bond) and C3 (19.05 ± 1.28 MPa -Clearfill SE) were comparable (p >0.05).
Viscostat and Expasyl result in compromised bond integrity of composite restoration to dentin in etch and rinse and self-etch group compared to no treatment group. However, the pre-application of Viscostat and Expasyl on dentin conditioned with PDT improved bond integrity of composite resin.