title: 22-Year clinical evaluation of the performance of two posterior composites with different filler characteristics.
abstract: OBJECTIVE
  This retrospective longitudinal study investigated the longevity of posterior restorations placed in a single general practice using 2 different composites in filler characteristics and material properties: P-50 APC (3M ESPE) with 70vol.% inorganic filler loading (midfilled) and Herculite XR (Kerr) with 55vol.% filler loading (minifilled).
  
  
  METHODS
  Patient records were used for collecting data. Patients with at least 2 posterior composite restorations placed between 1986 and 1990, and still in the practice for regular check-up visits, were selected. 61 patients (20 male, 41 female, age 31.2-65.1) presenting 362 restorations (121 Class I, 241 Class II) placed using a closed sandwich technique were evaluated by 2 operators using the FDI criteria. Data were analyzed with Fisher's exact test, Kaplan-Meier statistics, and Cox regression analysis (p<0.05).
  
  
  RESULTS
  110 failures were detected. Similar survival rates for both composites were observed considering the full period of observation; better performance for the midfilled was detected considering the last 12 years. There was higher probability of failure in molars and for multi-surface restorations.
  
  
  CONCLUSIONS
  Both evaluated composites showed good clinical performance over 22 years with 1.5% (midfilled) and 2.2% (minifilled) annual failure rate. Superior longevity for the higher filler loaded composite (midfilled) was observed in the second part of the observation period with constant annual failure rate between 10 years and 20 years, whereas the minifilled material showed an increase in annual failure rate between 10 years and 20 years, suggesting that physical properties of the composite may have some impact on restoration longevity.
authors.affiliation: Private Dental Practitioner, Caxias do Sul, RS, Brazil.
authors.forename: Paulo A
authors.initials: PA
authors.lastname: Da Rosa Rodolpho
authors.forename: Tiago A
authors.initials: TA
authors.lastname: Donassollo
authors.forename: Maximiliano S
authors.initials: MS
authors.lastname: Cenci
authors.forename: Alessandro D
authors.initials: AD
authors.lastname: Loguércio
authors.forename: Rafael R
authors.initials: RR
authors.lastname: Moraes
authors.forename: Ewald M
authors.initials: EM
authors.lastname: Bronkhorst
authors.forename: Niek J M
authors.initials: NJ
authors.lastname: Opdam
authors.forename: Flávio F
authors.initials: FF
authors.lastname: Demarco
mesh_terms: D000328:Adult; D001641:Bicuspid; D016009:Chi-Square Distribution; D003188:Composite Resins / Q000737:chemistry*; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000145:classification / Q000379:methods*; D003799:Dental Stress Analysis; D055119:Elastic Modulus; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D008963:Molar; D016016:Proportional Hazards Models; D019279:Resin Cements / Q000737:chemistry; D012189:Retrospective Studies
chemical_list: D003188:Composite Resins; C404623:P-50 APC; D019279:Resin Cements; C065770:Herculite XR