Evaluation of push-out bond strength of different concentrations of chitosan nanoparticles incorporated composite resin and eighth-generation bonding agent for class II restoration: An study.

Aim: The aim of this study is to evaluate the push-out bonding strength of class II cavities of maxillary molars restored with different concentrations of chitosan nanoparticles (CSN) incorporated in universal composite resin and eighth-generation dentin bonding agent (DBA).

Materials And Methods: Seventy extracted human maxillary first molar teeth were cleaned and mounted in acrylic mold up to 2 mm below cementoenamel junction and mesio-occlusal Class II cavities with standard measurements were prepared. CSN 2% and 0.25% powder were added to the DBA and composite resin. The samples then arbitrarily divided into three groups for restoration: Group 1: composite restoration without CSN (control group) ( = 10), Group 2: 2% CSN ( = 30), and Group 3: 0.25% CSN ( = 30). Groups 2 and 3 were further subdivided into three subgroups ( = 10 each) subgroup A. CSN incorporated in composite resin. B. CSN incorporated in DBA and C. CSN incorporated in composite and DBA. After restoration, push-out bond strength was evaluated in each sample using a universal testing machine, and data collected were statistically analyzed by one-way analysis of variance and Tukey tests ( ≤ 0.05).

Results: Subgroup 3A (0.25% CSN + composite) has shown an increase in bond strength among all experimental groups with no significant difference between group 1 (control group).

Conclusion: CSN 0.25% incorporated in composite or DBA exhibits no harmful effect on the bond strength of class II restorations. Hence, it can be used to improve the antibacterial action and longevity of composite resin.