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.

Inclusion Criteria:

• Healthy individuals with or without systemic disease
• Patiens older than 18 years old
• Good oral health
• Patients who at least have1 large and deep carious lesion or broken restoration in a vital tooth
• Patients who agreed to participate in the study after being informed about this study

Exclusion Criteria:

• Patient with periodontal disease
• Patients with partial dentures
• Patients with bruxism
• Patients with malooclusion
• Non vital or endodontically treated teeth
• Preparetions under the cemento-enamel junction