Comparison of Shear Bond Strength of Silorane and Nanohybrid Composite Resins to Calcium Enriched Mixture Cement in Different Time Periods

Statement of problem: It is crucial to select the best dental material for restoration of teeth that undergo vital pulp therapy after endodontic treatment. Objectives: Adhesion of composite resin and endodontic pulp capping material affect the outcome of treatment. The aim of the present study is to evaluate the adhesion of two different composite resins to calcium enriched mixture (CEM). Materials and Methods: We prepared a total of 60 cylindrical acrylic blocks that contained a central hole (4 mm diameter and 2 mm height). CEM cement was mixed according to the manufacturer’s instructions and introduced into the holes. We stored 30 specimens for 3 days and the remaining 30 specimens were stored for 7 days at 37ºC. The specimens were further divided into 2 subgroups based on the composite resins that we used. One subgroup of specimens was restored by Z350 (3M, ESP, St. Paul, MN, USA) nanohybrid and the other restored by P90 (3M, ESP, St. Paul, MN, USA) silorane based composite. Shear bond strengths were measured by a universal testing machine. Failure modes of the samples were evaluated under a stereomicroscope. Results: At day 3, P90 had significantly higher shear bond strength than Z350 (P=0.001). On day 7, Z350 had significantly higher shear bond strength compared to P90 (P=0.004). Conclusions: Within the limits of the present study, the best results of P90 silorane based composite filling after vital pulp therapy with CEM cement biomaterial were obtained after 3 days, whereas the Z350 nanohybrid composite showed better results on day 7.