Evaluation of the Effect of Applying Chitosan, Neem, Tulsi, Aloe vera, and Chlorhexidine Solutions on the Shear Bond Strength of Composite to Dentin.

Statement of the problem: Dentin adhesion is challenging and needs modifications. Newly introduced nature-derived materials may be a useful solution in improving dentin adhesion. The use of natural antimicrobial agents for pretreating prepared dentin surfaces before restoration has become of interest.

Purpose: The present study investigated the effect of natural compounds on the shear bond strength (SBS) of resin composite adhesively bonded to dentin.

Materials and method: Sixty extracted human molar teeth were randomly divided into six groups (n= 10); Group I: two-step etch and rinse adhesive system, Adper Single Bond 2 (SB₂) (experimental control), Group II: 2.5% Chitosan+etch+SB₂, Group III: 15% Neem (Azadirachta indica)+etch+SB₂, Group IV: 15% Tulsi (Ocimum sanctum)+etch+SB₂, Group V: 2% Aloe vera+etch+SB₂, and group VI: 2% Chlorhexidine (CHX)+etch+SB₂. Resin composite (Z350, 3M ESPE USA) was placed over the prepared dentin surfaces and was light cured. Data analysis was performed using One-way ANOVA and post hoc Tukey's test (p< 0.05).

Results: Neem specimens showed the highest mean SBS, statistically greater than the control (p= 0.042). Other experimental groups showed no significant differences in SBS comparison to the control. The mean SBS values of 2.5% Chitosan, 15% Neem, 15% Tulsi, and 2% Aloe vera were significantly higher than 2% CHX (p= 0.046, p= 0.001, p= 0.010 and p= 0.002 respectively).

Conclusion: Dentin pretreatment with Neem may improve the bond strength of a two-step etch and rinse adhesive system. The application of Chitosan, Tulsi, Aloe vera, and CHX did not demonstrate significantly different SBS values from that of the Control, although CHX was lower.