Introduction: Minimal cavity preparation of class II lesions and selection of a suitable restorative material are the optimal goals to obtain durable restorations.
Objectives: To evaluate the effect of a nano-filled coat on the 3D wear and fracture resistance of a glass hybrid restoration after cyclic loading in class II restorations in permanent teeth.
Materials and Methods: Compound occluso-mesial class II cavities were prepared in 44 premolars. Teeth were randomly allocated into 2 groups. Group 1 (Experimental Group): n= 22 teeth were restored with Equia Forte Fil plus Equia Forte coat. Group 2 (Control Group): n= 22 teeth were restored with Equia Forte Fil without its coat. All samples were subjected to fatigue by cyclic loading using ACTA type chewing simulator (50,000 cycles). 3D images were obtained before and after cyclic loading using a digital scanner. The wear resistance was evaluated by 3D image super-impositioning technique using CAD/CAM software. All samples were axially loaded till fracture utilizing a universal testing machine. Data normality was checked using Shapiro Wilk test and box plot. Groups were compared using the parametric independent t test. Significance level was set at P=0.05.

Results: CAD/CAM qualitative evaluation of the uncoated group showed massive amounts of wear when compared to the coated group. The coated group also demonstrated a significantly higher fracture resistance than the uncoated group (P