Clinical Performance of Different Resin Cements

The clinical performance of different resin cements in adhesion of hybrid ceramic inlay and onlay restorations produced with CAD/CAM will be evaluated and compared. After obtaining a signed informed consent form from all the patients, all restorations will be placed by a single clinician. All hyrid ceramic restorations (Cerasmart, GC, Tokyo, Japan) will be produced using the same CAD/CAM CEREC Omnicam (Sirona Dental, Bensheim, Germany) system. 70 restorations will be divided into 2 groups: a self adhesive resin cement (RelyX U200 Automix, 3M ESPE, Seefeld, Germany), and an adhesive cement (G-Cem LinkForce, GC, Tokyo, Japan) which is applied after surface treatment (etch\&rinse). All restorative procedures will be conducted according to manufacturers' instructions. Restorations will be scored using modified United States Public Health Service (USPHS) criteria after baseline, 6,12, 18, 24, 36 and 48 months. Descriptive statistics will be performed using Friedman test and Chi-square test.