COMPARATIVE EVALUATION OF SHEAR BOND STRENGTH OF A BIOACTIVE COMPOSITE AND NANO-COMPOSITE: AN IN VITRO STUDY

Objectives: The aim of this study was to determine and compare the shear bond strength of activa bioactive restorative with and without adhesive and nano-composite.
Materials and Methods: Sixty freshly extracted human premolars were used. The teeth were mounted vertically in a self-cure acrylic cylinder. A high-speed fine diamond disk with copious wa­ter spray was used to obtain a flat dentin of the labial surface. One clinician prepared all the teeth. The teeth were divided into three groups twenty teeth each, n=20 Group I : The flat dentin surfaces were acid-etched for 15 sec with 37% phosphoric acid, it washed and dry then application of bioac­tive composite into a plastic ring measuring 3mm width and 2 mm depth. Each specimen was light cured for 40 sec by LED light cure unit. Group II: The flat dentin surfaces were acid-etched and then two coats of bonding agent was applied over each specimen and light cured for 20 sec. then application of bioactive composite. Group III (Control): The flat dentin surfaces were acid-etched and application of bonding agent then nano-composite applicated into a plastic ring measuring 3mm width and 2 mm depth. Each specimen was light cured for 40 sec by LED light cure unit. All of the specimens were tested for shear bond strength and all of the data were analyzed by One way analysis of variance (ANOVA) and Tukey’s post hoc test.
Results: Results showed that the highest mean value was detected in Nanocomposite, fol­lowed by bioactive composite with adhesive, the mean shear bond strength of Nanocomposite and composite with adhesive was significantly greater than bioactive composite without adhesive (p<0.0001).
Conclusions: Nanocomposite showed higher shear bond strength followed by bioactive com­posite with adhesive, while bioactive composite without adhesive showed the lowest shear bond strength value