Comparative evaluation of effect of three different MMP inhibitors on flexural bond strength of resin composite used to restore NCCL - In vitro study

Interface between resin composite and dentin is critical and important for the success of restoration. Application of MMP inhibitor may alter surface characteristic of dentin that improves bond strength of resin composite. This study evaluated and compared the effect of three different Matrix Metalloproteinase (MMP) inhibitors on flexural bond strength of resin composite restorations; done to restore non carious cervical lesions (NCCL). : Standardized NCCL was simulated on 41 freshly extracted and selected human premolars. The teeth were randomly assigned into four groups i.e. Group I: Control group (no MMP inhibitor). Group II: Chlorhexidine. Group III: Chitosan and group IV: Proanthocyanidin. NCCL were pretreated with MMP inhibitor of respective group prior to its restoration with nanofilled resin composite. Restorations in each group were finished and polished with an appropriate finishing and polishing kit. The flexural bond strength was evaluated using the universal testing machine. Data were analysed using one-way analysis of variance and Tukey's test. Among the tested MMP inhibitors; Group II (90.73 Mpa) and Group III (90.17 Mpa) showed highest mean flexural bond strength with insignificant difference ( P = 1.0) between them. Group IV showed higher but insignificantly different (P= 0.768) flexural bond strength to that of group I. Group II and Group III worked best to increase the flexural bond strength of resin composite indirectly representing its higher MMP inhibition and collagen stabilizing activity than Group IV and Group I.