Evaluation of Effective Bond Strength of Composite Resin to Etched Dentin after Dentin Pretreatment: An In-vitro Study

Aims: The aims of the study were to compare the deproteinizing effect of sodium hypochlorite, doxycycline, ethylenediaminetetraacetic acid (EDTA), and chitosan on effective shear bond strength of bonded composite resin to etched dentin. Materials and Methods: Forty extracted human maxillary premolars were taken, which were placed in a metal mold with acrylic resin. Teeth were divided into four groups according to the deproteinizing agents used, which are 5% NaOCl, 2% doxycycline, 17% EDTA, and 1% chitosan. Occlusal reduction of 1 mm below the dentin–enamel junction was done. Dentin deproteinizing agents were applied for 60 s and blot dried after acid etching. A universal dentin bonding agent was brushed and light cured. Cylindrical molds with composite resin were placed on the bonded surface and light cured. The shear bond strength was measured using a universal testing machine with a crosshead speed of 1.3 mm/min. Statistical Analysis Used: The Statistical Package for the Social Sciences (SPSS) for Windows, Version 22.0. released in 2013. Armonk, NY, USA: IBM Corp. was used to perform statistical analyses. One-way ANOVA test followed by Tukey’s Post hoc test was used to compare the mean shear bond strength between different groups. Results: Deproteinizing agent chitosan showed more bond strength compared to the other three agents used. Two percent doxycycline showed better shear bond strength followed by 5% NaOCl and 17% EDTA which had the least value for shear bond strength. Conclusions: Within the limitations of the present study, deproteinizing agents, when used after acid etching the dentin, can increase the bond strength. Chitosan showed to have a better deproteinizing effect compared to other agents used in the study.