Evaluation of Using Self-adhering Flowable Resin Composite in Repairing Old Defective Resin Composite Restorations Over 18 Months Follow up. (A Randomized Clinical Trial)

Inclusion Criteria: * Patients (18-35 y) * patients with defective resin composite class I restorations that need repair. * dental motivated patients who attends regularly. * Vital posterior teeth with repairable defective resin composite class I restorations. * Localized marginal defect or marginal staining FDI 3\& 4. * Teeth with no or minimum mobility \& healthy peridontium. * No history of any irreversible pulpal pain or necrosis in the teeth to be restored. Exclusion Criteria: * • Patients with defective restorations that dictate replacement * Uncooperative behavior limits the isolation techniques throughout the procedure. * Presence of parafunctional habits. * Patient with history of systemic medical disease, or any other serious relevant problem. * High caries risk patients. Periodontal disease that may affect the prognosis of the restoration or the tooth itself. * Fractured or visibly cracked teeth. * Symptoms of any pulp pathosis. * Defective resin composite restorations that dictate replacement.