Clinical success of resin composite -restored endodontically treated molars

Objectives: The aims were to investigate the survival of endodontically treated molars restored with bonded composite restoration and to identify possible related factors. Methods: 195 endodontically treated permanent molar teeth in 188 subjects on a waiting list for fixed prosthodontic treatment at the Faculty of Dentistry-Mahidol University, Thailand, were evaluated. Follow-up data were derived from a clinical examination, review of the dental record and radiograph. Teeth that had provisional crowns, definitive restorations with cuspal coverage, or with dowel and core and/or crown restorations were not included in the study. The outcome evaluated was defined as failure if there were negative findings in the condition of a tooth that required a restoration, tooth repair, or extraction. Tooth loss due to endodontic and periodontal reasons was excluded. The independent factors assessed were patient age, gender, location (maxilla or mandible), the existence of an opposing dentition and adjacent teeth, remaining tooth structure. Kaplan-Meier analysis with a 95% confidence level was used to calculate the survival probability and a logrank test was used to determine whether significant differences existed. Results: Overall survival rates of endodontically treated molars restored with resin composite at 1, 2 and 5 years were 96%, 90% and 38%, respectively. With more amount of coronal tooth structure remaining, the survival probability increased. Molar teeth with maximum tooth structure remaining after endodontic treatment had a survival rate of 85% at 5 year. Conclusion: Within the limitations of this study, in general, endodontically treated molars that were not restored with fixed restorations, but had intracoronal, resin composite restorations without dowels were shown to have survival rate of at least 90% in the first two years. The amount of remaining tooth structure had significant effect on tooth survival.