A comparative evaluation of shear bond strength of composite resin to pulp chamber dentin treated with sodium thiosulfate and proanthocyanidin: An in vitro study

Abstract

<b>Aim:</b> Based on the importance of coronal sealing right after endodontic treatment, this <i>in vitro</i> study aimed to evaluate the difference of shear bond strength to pulp chamber dentin treated with sodium thiosulfate and proanthocyanidin (PA).<br><b>Materials and Methods:</b> Fifteen extracted mandibular molar teeth were decoronated at the level of cementoenamel junction horizontally. The individual teeth were then sectioned mesiodistally to expose the pulp chamber dentin using a diamond disc. The specimens were randomly divided into three groups (<i>n</i> = 10). Group A: control group, treated with 5.25% sodium hypochlorite (NaOCl) for 30 min followed by a final rinse with 17% ethylenediaminetetraacetic acid (EDTA) solution for 3 min; Group B: after pretreatment with NaOCl and EDTA, it is further treated with 5% sodium thiosulfate (Na₂S₂O₃) for 10 min; and Group C: after pretreatment with NaOCl and EDTA, it is further treated with 6.5% PA for 10 min. After drying the specimens, a bonding agent namely One Coat Bond SL (SwissTEC, Coltene) was applied to the pulp chamber dentin followed by a composite restoration (SwissTEC, Coltene). Each specimen was then tested under a universal testing machine at the dentin/resin interface to determine the shear bond strength.<br><b>Results:</b> Both the groups in which 5% Na₂S₂O₃ and 6.5% PA were used for 10 min showed bond strength that was found to be statistically higher than the positive control (<i>P</i> < 0.05).<br><b>Conclusion:</b> The use of Na₂S₂O₃ and PA can significantly increase the bond strength of composite resin to NaOCl/EDTA-treated dentin, allowing adhesive restorations to be immediately applied after endodontic treatment.