Clinical performance of indirect adhesive restorations - onlays, overlays- luted with light-cured composite resin will be evaluated.

Indirect adhesive restorations are indicated in large Class II defects, replacement of large compromised existing restorations or endodontically treated teeth where cuspal protection is required. The need to perform adhesive restorations of posterior teeth is not only linked to esthetic purposes, but also have possibility of strengthening the remaining tooth structure. Indirect technique decreases polymerization shrinkage, reduces microleakage and also improves the marginal seal when comparing direct resin composites. Furthermore, it provides improved physical and mechanical properties, ideal occlusal morphology, more precise control of proximal contours and contacts. Indirect adhesive restorations are classically delivered with an adhesive procedure including dual-cure cement. Updated approaches now include the use of composite resins as luting agent.

This study will be carried out as a prospective study, with assessment of the restorations after three years. PASS 11 Software was used to calculate the sample size. At least 77 indirect adhesive restorations will be included for this study. Patients referred to Istanbul Okan University Faculty of Dentistry between 2016-2017 who had returned for the baseline recall and at least one year recall after the treatment will be invited for eligibility to participate in the study. 83 indirect adhesive restorations in at least 60 patients will be included. The patients who will not meet all the inclusion criteria will be excluded from the study. A signed informed consent form will be obtained from all patients before beginning the study.

Restorations will be evaluated clinically according to FDI World Dental Federation criteria. Three main groups- esthetic, functional, biological properties- and their sub-categorizes of FDI World Dental Federation criteria will be scored on a scale of 1 to 5. Statistical analysis will be performed using R (v.3.5.3) Software and the SIGN.test function in the BSDA package (p <0.05).

Inclusion Criteria:

• Significant loss of dental hard tissue
• Endodontically treated teeth in posterior region
• Replacement of large compromised existing restoration
• Large Class II restoration
• Age of 18-60 years
• Good oral hygiene
• Presence of interproximal contact to at least one neighboring teeth • In occlusion with antagonist teeth
• Cavity preparation with at least one cuspal coverage

Exclusion Criteria:

• Serious medical problems or allergies to substances and/or products to be used
• Severe periodontal problems
• Poor oral hygiene
• Direct pulp capping
• Presence of parafunctional behaviors
• Pregnant or breast feeding