OBJECTIVE- The aim of this in vitro study is to evaluate and compare the effect of two different antioxidants – 6.5% proanthocyanidin and 10% ascorbic acid on the bond strength of composite resin to pulp chamber dentin treated with sodium hypochlorite and ethylenediamine tetraacetic acid. MATERIALS AND METHODS- Thirty extracted human mandibular molar teeth were sectioned in a mesiodistal direction to expose the pulp chamber to obtain a total of sixty samples. The enrolled specimens were divided into 3 groups: Control Group(n=20), treated with 3% sodium hypochlorite (NaOCl) for 5 mins followed by treatment with 17% ethylenediamine tetraacetic acid (EDTA) for 5 mins ; Group A (n=20) ,after pretreatment with NaOCl and EDTA , the specimens were immersed in a solution of 6.5% Proanthocyanidin (PA) for 10 mins ; Group B(n=20) , following pretreatment with NaOCl and EDTA , specimens were further treated with 10% ascorbic acid solution for 10 mins. After drying the specimens, a self-etch adhesive, Prime and Bond Tm (Dentsply Caulk) was applied on pup chamber dentin followed by composite restoration (Ceram X Tm Sphere Tec Tm One Universal, Dentsply Sirona). Each specimen was then tested under a universal testing machine at dentin/resin interface to determine shear bond strength. RESULTS- The group in which 6.5% PA was used showed significantly higher bond strength than the 10% ascorbic acid group followed by the control group. (p <0.05). CONCLUSION- Within the limits of this in vitro study it can be concluded that immediate application of proanthocyanidin and ascorbic acid can restore the compromised bond strength of composite resin to NaOCl/EDTA treated dentin. Proanthocyanidin can improve the bond strength significantly more than ascorbic acid.
Key words: Sodium Hypochlorite, Ehylenediamine Tetraacetic Acid, Proanthocyanidin