Comparative Evaluation of Different Antioxidants on Reversal of Microtensile Bond Strength of Composite Resin in Endodontically Treated Tooth Surface ZC43-ZC46
Additional Professor, Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, King George’s Medical University, Lucknow, India.
Introduction: The use of Sodium Hypochlorite (NaOCl) as an endodontic irrigant changes the properties of dentine and lowers the bond strength of resin cements to the dentine, but it can be reversed by the use of antioxidants.
Aim: To evaluate the effect of antioxidants for restoring adhesion potential/reversal of microtensile bond strength of dentin in the pulp chamber treated with NaOCl and Ethylenediaminetetracetic Acid (EDTA).
Materials and Methods: This is a laboratory based experimental in-vitro study in which 40 freshly extracted human incisors were selected and cut to expose the pulp chamber below the dentine. The specimens were distributed among five groups: Group I samples were irrigated with 5.25% NaOCl for 30 minutes followed by 17% EDTA for 3 minutes and final rinse was done with 5.25% NaOCl (Positive control). Group II samples were treated with distilled water only (Negative control). In Group III, samples were treated same as in group I followed by 10% Sodium Ascorbate (SA) for 10 minutes. Samples of group IV were also treated as in group I followed by application of 5% solution of Alpha tocopherol for 10 minutes. Group V samples were treated same as in group I followed by a rinse with 5% solution of Sodium Thiosulphate (Na2S2O3 ) for 10 minutes. Composite resin build up was performed and interface was tested by using Universal testing machine for Microtensile bond strength. The resulting data was analysed by one-way Analysis of Variance (ANOVA) and Mann-Whitney U test (p<0.05).
Results: The results demonstrated that irrigation with 5.25% NaOCl and 17% EDTA produce significant (p<0.05) reduction in resin dentin bond strength but this could be reversed by application of 5% Na2S2O3 . Highest bond strength was observed in group V (22.38±0.84) and lowest for group I (15.38±1.22).
Conclusion: Dentin bond strength was significantly reduced when bonding was performed immediately after use of NaOCl. Use of antioxidants after final irrigation with NaOCl can be recommended for better bonding of composite resin.