Comparative evaluation of the effect of 10%, 20%, and 30% guava seed extract on reversing compromised resin bond strength after enamel bleaching in 120 min, 10 min, and 5 min: An in vitro study

Background:

Bonding of composite with enamel and dentin gets compromised if the tooth is restored with composite immediately post bleaching. The application of antioxidants has shown to have a positive effect on it.

Aim:

The aim of this study was to evaluate and compare the effect of guava seed extract solutions in various concentrations on the shear bond strength (SBS) of composite resin to bleached enamel when applied for 5 min, 10 min, and 120 min.

Materials and Methods:

Fifty-five maxillary incisors were procured, and labial surfaces of 50 specimens were bleached with 37.5% hydrogen peroxide. These specimens were divided into 3 experimental groups: Group 1–3 comprising 15 specimens each (n = 15), and the remaining specimens were divided into two groups: Group 4 (positive control group) and Group 5 (negative control group). Groups 1–3 were further divided into 3 subgroups according to the application period of antioxidant: subgroups A, B, and C. Specimens were stored in distilled water for 24 h. SBS testing was done using the universal testing machine. Data were tabulated and subjected to statistical analysis using a three-way analysis of variance with post hoc Tukey's test.

Results:

Guava seed extract showed a complete reversal of the compromised bond strength, and promising results were seen with increased concentration.

Conclusion:

The use of antioxidants effectively reversed the compromised bond strength of bleached enamel, and an increase in the concentration of antioxidants reduces the duration of its application.

Effect of different antioxidants on reversing compromised resin bond strength after enamel bleaching: An in vitro study

OBJECTIVE

The effect of 10% sodium ascorbate, 10% α-tocopherol, 10% grape seed extract, and 10% guava seed extract solutions on the shear bond strength (SBS) of composite resin to bleached enamel was evaluated.

MATERIALS AND METHODS

Labial enamel surfaces of 72 extracted maxillary central incisors were bleached using 37.5% hydrogen peroxide. Sixty-four specimens were divided into four experimental groups (Group I-IV) comprising 16 specimens each and remaining eight specimens were placed in Group V. Groups I-IV were further divided into 2 subgroups: A (10 min) and B (120 min) comprising 8 specimens each. Eight unbleached specimens served as control (Group VI). Immediately following bleaching, Groups IA-IVA and IB-IVB specimens were treated with respective antioxidants for 10 min and 120 min. All specimens were then bonded with composite resin. Specimens were stored in distilled water for 24 h. SBS testing was done. Data were tabulated and subjected to statistical analysis using ANOVA and Tukey's honest significant difference test.

RESULTS

Group VI (unbleached) showed the highest SBS followed by Group IV (10% guava seed extract).

CONCLUSION

Use of antioxidants effectively reversed the compromised bond strength of bleached enamel. About 10% guava seed extract application after bleaching showed best bond strength.