Predictors of procedural errors in class II resin composite restorations using bitewing radiographs

•Bitewing radiographs for proximal resin composite restorations performed by dental students were assessed for different procedural errors.•The most observed procedural errors were internal gaps at the bonding interface and internal voids.•Molars had 0.39 the risk of internal voids, 0.41 the risk of sharp angle, and 0.57 the risk of open contact compared to premolars.•This study reinforces the conclusions drawn from previous articles, which indicate a strong correlation between dental students and procedural errors in proximal resin composite restorations.•Dental schools may consider adopting new tools and approaches to teach proximal resin composite restoration placement effectively. To identify the potential factors that induce procedural errors during posterior proximal resin composite restorations placed by dental students. This retrospective study evaluated 803 bitewing radiographs of posterior proximal resin composite restorations placed by dental students at Imam Abdulrahman bin Faisal University. Atypical radiographic signs of failure were screened, and different patient-, operator-, and clinical-related factors were recorded. Chi-square test was used to examine the relationship between procedural errors and recorded factors. Stepwise adjusted logistic regression model was performed to identify predictors of procedural errors. The most observed errors were internal gaps at the bonding interface and internal voids. Molars had 0.39 the risk of internal voids (odds ratio [OR] = 0.39; confidence interval [CI] = 0.25–0.60; P =