Effect of 30% Grape Seed Extract on the Shearbond Strength of Orthodontic Adhesive Resin: An In-vitro Study

Abstract

Introduction: Grape Seed Extract (GSE) contains Proanthocyanidins (PA) which have been shown to cross-link and strengthen demineralised dentin collagen. There is paucity of research to evaluate if grape seed extract increases the shear bond strength of orthodontic resin when bonding to enamel. Aim: To evaluate the shearbond strength and Adhesive Remnant Index (ARI) scores of enamel surface bonded with orthodontic resin after immersing in 30% of grape seed extract and compare the same with that of control group. Materials and Methods: In this in-vitro study, 72 extracted teeth samples were divided into two groups. The two groups, each with 36 specimens, included Group I (Control), Group II (Test). Teeth in the test group were soaked in 30% grape seed extract for 10 minutes before bonding and teeth in the control group were bonded directly without soaking in grape seed extract. Shearbond strength were measured using a Universal testing machine. To evaluate the amount of resin left on the enamel surfaces after debonding, ARI scores were used. The samples were subsequently evaluated using Scanning Electron Microscope (SEM) to study the surface characteristics of enamel after immersion in grape seed extract. Student t test was used to assess the difference between two groups in shear bond strength and Chi-square test was used for ARI scores. Results: Total of 72 teeth were analysed, 36 extracted teeth in each group. The mean shearbond strength in Group I was 78.9 Newton (N), 59.03 N in Group II. There was a stastistically significant differences in the mean scores of shearbond strength between the groups (p-value=0.0024). The shearbond strength of control group was significantly higher than the Test group. Significant difference(p-value=0.016) found in ARI scores between the two groups. In SEM analysis after grape seed extract conditioning followed by acid etching, pronounced cobble stone appearance was noticed indicating a type II etching pattern. Conclusion: Adhesive failure occurred at the resin and bracket interface indicating that shear bond strength reduces when teeth were immersed in Grape Seed Extract.