Restoration of Non-carious Cervical Lesions: The Effect of Different Resin Composites Bonded With A Universal Adhesive Utilizing Two Adhesion Approaches: A Randomized Clinical Study

A split-mouth randomized clinical trial (RCT), based on the adhesion strategy, will be held on 52 patients attending to the outpatient clinics of the department of operative dentistry, Faculty of Dentistry, Ain Shams University with 2 non-carious cervical lesions in each side. Patients included in this study are those who seek restorative treatment of non-carious cervical lesions (NCCLs) in premolars and canines, which are due to chemical and/or mechanical predisposing factors. An informed consent will be signed by all participants who will be allocated in this study before being involved in the study. Male and female patients will be selected according to the inclusion and exclusion criteria. The patients will be randomly assigned into 4 main groups (n=13 patients/group) according to the type of restorative material will be inserted. In each group, two adhesive approaches will be employed, either etch-and-rinse (E&R) or self-etching (SE)approach. For each patient's mouth, one side will receive restorations with the etch-and-rinse approach (n=26 restorations/E&R approach), while the other side will receive restorations using the self-etching approach (n=26 restorations/SE approach). This will result in a total of 208 restorations will be inserted in this study. A treatment follow-up will be performed every six months for two years to investigate the clinical performance of the different resin composite restorations/the two different adhesive approaches.

Restorations will be evaluated at baseline and every 6 months by two blinded examiners, who will not be involved in the study. During evaluation, the examiners will not be informed about the type of restoration used or the adhesive approach and will have a code for each patient and the restored tooth. Restorations will be evaluated according to the modified United State Public Health Service criteria (USPHS).(6,9,13,30) Primary outcome will be the retention of the restoration, but the following secondary outcomes as marginal discoloration and adaptation, anatomic form, secondary caries, texture, and postoperative sensitivity will be also evaluated.