Survival Rate of Direct Posterior Composite Resin Restorations at a Southern California Dental School

Background The study’s purpose was to assess the survival rates and associated factors affecting posterior composite resin restorations placed by dental students at a Southern California Dental School (SCDS).Methods Retrospective data from patient records were reviewed, including direct composite resin restorations placed on posterior permanent teeth from January 2018 to April 2018. Data analysis included patient age, gender, number of surfaces, primary reason for restoration, method of isolation, and reasons for failure. The longevity of the restorations was evaluated by the Kaplan–Meier survival analysis, with detailed at-risk tables provided for each subgroup, significance was set at alpha = 0.05.Results The search yielded 792 patient records (57% female and 43% male, age range: 18–99) with 1,457 restorations. Overall, the 1-year survival rate was 91%, while the 5-year survival rate reduced to 86%. The log-rank test identified that Age group (p = 0.004) was the only variable with a statistically significant effect on the survival rates of dental procedures. Younger patients (<30) had markedly lower survival probabilities, while those in the 51–70 age range showed the highest.Conclusions We conclude that the 5-year survival rate of direct composite resin restorations in posterior teeth placed by dental students was 86% and therefore deemed acceptable. The survival rate was impacted by age, highlighting the importance of considering age when assessing procedural risk and expected outcomes, particularly those under the age of 30.Practical Implications This retrospective study provides useful insights into the longevity of composite restorations in a dental educational setting.