title: Longevity of posterior dental restorations and reasons for failure.
abstract: Tooth-coloured restorative materials are being used increasingly more often in Class II preparations in permanent teeth. Using a practice-based study design, we aimed to assess the survival time of Class II restorations and to identify factors relevant to their longevity. Class II restorations (n = 4,030), consisting of resin composites (81.5%), compomers (12.7%), amalgams (4.6%), and glass-ionomer cement restorations (1.2%), were placed in 1,873 patients with a median age of 15 yr. In total, 92.7% of restorations were placed due to primary caries and 5.8% were replacements. After an average follow-up period of 4.6 yr, 61.6% of the restorations were successful, 11.2% had failed, and 27.2% were not available for evaluation (owing to patient drop-out). The mean annual failure rate was 2.9% for resin-composite restorations and 1.6% for amalgams. For resin-composite restorations, secondary caries was the most common reason for replacement (73.9%), followed by loss (8.0%), fracture (5.3%), and marginal defects (2.4%). Multilevel Cox-regression analyses identified young age of the patient, high previous caries experience, deep cavities, and saucer-shaped preparation technique as predisposing to shorter longevity of resin-composite restorations. One brand of resin composite had a shorter survival time than the others.
authors.affiliation: Faculty of Dentistry, University of Oslo, Oslo, Norway. simen.vidnes-kopperud@odont.uio.no
authors.forename: Simen E
authors.initials: SE
authors.lastname: Kopperud
authors.forename: Anne Bjørg
authors.initials: AB
authors.lastname: Tveit
authors.forename: Torunn
authors.initials: T
authors.lastname: Gaarden
authors.forename: Leiv
authors.initials: L
authors.lastname: Sandvik
authors.forename: Ivar
authors.initials: I
authors.lastname: Espelid
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003764:Dental Materials; D019232:Dental Restoration Failure / Q000706:statistics & numerical data*; D003793:Dental Restoration, Permanent / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009664:Norway; D012044:Regression Analysis
chemical_list: D003764:Dental Materials