title: Seventeen-year clinical study of ultraviolet-cured posterior composite Class I and II restorations.
abstract: OBJECTIVE
  To compare the clinical performance of four commercial ultraviolet light-cured composite materials, and to evaluate curing-system effects on long-term wear resistance of Class I and II restorations.
  
  
  METHODS
  Approximately 32 samples of each of four different ultraviolet light-cured composites (n = 130) were inserted into conventional Class I and II cavity preparations by two clinicians. Cavosurface margins of the preparations were not beveled. Enamel walls of the preparation were etched, and the respective bonding agent was applied. Each restoration was evaluated by two clinicians at 5, 10, and 17 years. Direct evaluations were performed using modified United States Public Health Service (USPHS) criteria. Indirect evaluations were performed using the Leinfelder cast evaluation method.
  
  
  RESULTS
  After 17 years, 65% of the restorations were recalled and pooled direct evaluations were conducted for color matching (94% alfa), marginal discoloration (100% alfa), marginal integrity (100% alfa), secondary caries (92% alfa), surface texture (72% alfa), and anatomic form (22% alfa). Mean occlusal wear from indirect evaluations at 5, 10, and 17 years was 197 +/- 85 microns, 235 +/- 72 microns, and 264 +/- 80 microns, respectively. For direct and indirect evaluations there were significant differences (p < or = .05) between the baseline and 5-year recall evaluations.
  
  
  CONCLUSIONS
  This study demonstrated that the mean pooled occlusal wear of four ultraviolet light-cured posterior composites at 17 years was 264 microns (approximately 0.25 mm), and that most wear (75%) occurred in the first 5 years. Of all recalled restorations, 76% were judged clinically acceptable at 17 years, and 22% of those exhibited no clinically detectable wear.
authors.affiliation: Department of Operative Dentistry, School of Dentistry, University of North Carolina at Chapel Hill, USA.
authors.forename: A D
authors.initials: AD
authors.lastname: Wilder
authors.forename: K N
authors.initials: KN
authors.lastname: May
authors.forename: S C
authors.initials: SC
authors.lastname: Bayne
authors.forename: D F
authors.initials: DF
authors.lastname: Taylor
authors.forename: K F
authors.initials: KF
authors.lastname: Leinfelder
mesh_terms: D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects; D003731:Dental Caries; D018772:Dental Marginal Adaptation; D019554:Dental Restoration Wear; D003793:Dental Restoration, Permanent / Q000379:methods*; D005500:Follow-Up Studies; D006801:Humans; D011108:Polymers / Q000737:chemistry; D012044:Regression Analysis; D018709:Statistics, Nonparametric; D013499:Surface Properties; D014075:Tooth Discoloration; D016896:Treatment Outcome; D014466:Ultraviolet Rays
chemical_list: D003188:Composite Resins; D011108:Polymers