Long-term clinical evaluation of direct resin composite restorations in vital vs. endodontically treated posterior teeth - Retrospective study up to 13 years

Abstract

Objectives: This retrospective study evaluated and compared the survival rate of Class II posterior direct resin based composite (RBC) restorations made in vital teeth (VT) and endodontically treated teeth (ETT). The influence of risk factors on the long-term performance of restorations was also investigated.

Methods: Patients (n=245) receiving RBC posterior restorations between 2004 and 2012 were selected. A total of 597 restorations (485 in VT, 112 in ETT) with minimum 2.5-3mm remaining cusp thickness, made with the same brand of RBC and adhesive, were evaluated using the USPHS criteria. Data were analyzed with Mann-Whitney, Chi-square and Fisher's Exact Test, Extended Cox-regression and Kaplan-Meier analysis (p<0.05). Relative risk ratio was estimated for each evaluated parameter.

Results: The mean observation period was 8.6±2.3 years. An annual failure rate in VT and ETT of 0.08% and 1.78%, respectively, was detected. The reasons of failures included restoration fracture, secondary caries in VT; vertical root fracture, cusp fracture, restoration fracture, secondary caries and loss of adhesion in ETT. Significantly better performance was observed in RBCs of VT for each evaluated parameter. Among the evaluated risk factors only occlusal stress affected negatively the survival of RBC in ETT (Hazard Ratio 37.1; CI_95% 8.4-163.7).

Significance: Although, there is significant difference in the success rate of RBCs in VT (98.97%) and ETT (76.8%), the long-term (6-13 years) durability of Class II RBCs with 2.5-3mm cusp thickness in ETT is also clinically acceptable. The presence of occlusal stress decreases the survival of RBCs in ETT.

Keywords: Class II restoration; Endodontically treated teeth; Longevity; USPHS evaluation.