title: Clinical performance of ormocer, nanofilled, and nanoceramic resin composites in Class I and Class II restorations: a three-year evaluation.
abstract: OBJECTIVE
  This prospective long-term clinical trial evaluated and compared the three-year clinical performance of an ormocer, a nanofilled, and a nanoceramic resin composite with that of a microhybrid composite placed in Class I and Class II cavities.
  
  
  METHODS
  Forty patients, each with four Class I and II restorations under occlusion, were enrolled in this study. A total of 160 restorations were placed, 25% for each material, as follows: an ormocer-based composite, Admira; a nanofilled resin composite, Filtek Supreme XT; a nanoceramic resin composite, Ceram X; and a microhybrid resin composite, Tetric Ceram. A single operator placed all restorations according to the manufacturers' instructions. Immediately after placement the restorations were finished/polished. Clinical evaluation was performed at baseline and at yearly intervals after placement by two other independent examiners using modified US Public Health Service (USPHS) criteria. The changes in the USPHS parameters during the three-year period were analyzed with the Friedman test. Comparison of the baseline scores with those at the recall visits was made using the Wilcoxon signed rank test. The level of significance was set at p < 0.05.
  
  
  RESULTS
  All materials showed only minor changes, and no differences were detected between their performance at baseline and after three years. Only two ormocer, one nanofilled, and one microhybrid restorations in molars failed because of loss of retention. Regarding the clinical performance, there were no statistically significant differences among the materials used (p>0.05).
  
  
  CONCLUSIONS
  The ormocer, nanofilled, and nanoceramic composites provided acceptable clinical performance over a three-year period.
authors.forename: S H
authors.initials: SH
authors.lastname: Mahmoud
authors.forename: A E
authors.initials: AE
authors.lastname: El-Embaby
authors.forename: A M
authors.initials: AM
authors.lastname: AbdAllah
mesh_terms: D000328:Adult; D003188:Composite Resins / Q000627:therapeutic use*; D003731:Dental Caries / Q000628:therapy; D003793:Dental Restoration, Permanent / Q000379:methods* / Q000592:standards; D006801:Humans; D008689:Methacrylates / Q000627:therapeutic use; D008875:Middle Aged; D049329:Nanostructures / Q000627:therapeutic use; D063225:Organically Modified Ceramics / Q000627:therapeutic use*; D011446:Prospective Studies; D012833:Siloxanes / Q000627:therapeutic use; D013997:Time Factors; D055815:Young Adult
chemical_list: C520091:CeramX; D003188:Composite Resins; C474035:Filtek Supreme; D008689:Methacrylates; D063225:Organically Modified Ceramics; D012833:Siloxanes; C121818:Tetric ceram; C479084:admira