Prevalence and Determinants of Reintervention in Defective Composite Restorations Among Dental Students

Background: Posterior resin composite restorations are widely used because of their esthetic properties and minimally invasive approach. However, they may deteriorate over time due to secondary caries, fracture, marginal defects, and other clinical factors. The decision to repair or replace a defective restoration is an important aspect of contemporary restorative dentistry, and patient-related behavioral factors and dentists’ knowledge of composite repair may influence clinical outcomes and treatment decisions. The aim of this study was to assess the prevalence of defective posterior composite restorations and factors associated with reintervention among dental students. Methodology: A cross-sectional study of 300 students at the Faculty of Dentistry, University of Benghazi evaluated posterior composite restorations older than one year using modified USPHS criteria. Data were analyzed with IBM SPSS Statistics using descriptive statistics, Chi-square tests, and logistic regression (p < 0.05). Results: 21% of restorations were defective, mainly due to fracture and secondary caries. Most showed acceptable marginal adaptation and surface texture. Good oral hygiene reduced failure risk, while parafunctional habits increased it. Only 41.7% of students had formal training in composite repair. Conclusion: Although posterior composite restorations performed satisfactorily overall, their outcomes were strongly influenced by behavioral factors. Most restorations remained clinically acceptable; however, secondary caries and fracture were the primary reasons for reintervention. The educational gaps in composite repair identified among students highlight the need for stronger emphasis on minimally invasive restorative approaches within dental curricula.