Longevity of direct restorations in Dutch dental practices. Descriptive study out of a practice based research network

Abstract Objectives The aim of this retrospective practice-based study was to investigate the longevity of direct restorations placed by a group of general dental practitioners (GDPs) and to explore the effect of practice/operator, patient, and tooth/restoration related factors on restoration survival. Methods Electronic Patient Files of 24 general dental practices were used for collecting the data for this study. From the patient files, longevity of 359,548 composite, amalgam, glass-ionomer and compomer placed in 75,556 patients by 67 GDPs between 1996 and 2011 were analyzed. Survival was calculated from Kaplan-Meier statistics. Results A wide variation in annual failure rate (AFR) exists between the different dental practices varying between 2.3% and 7.9%. Restorations in elderly people (65 years and older, AFR 6.9%) showed a shorter survival compared to restorations placed in patients younger than 65 years old (AFR 4.2%–5.0%). Restorations in molar teeth, multi-surface restorations and restorations placed in endodontically treated teeth seemed to be more at risk for re-intervention. Conclusion The investigated group of GDPs place restorations with a satisfactory longevity (mean AFR 4.6% over 10 years), although substantial differences in outcome between practitioners exist. Several potential risk factors on practice/operator, patient, and tooth/restoration level have been identified and require further multivariate investigation.