title: A 3-year clinical evaluation of a compomer, a composite and a compomer/composite (sandwich) in class II restorations.
abstract: OBJECTIVE
  To compare the clinical performance of Dyract, Spectrum-TPH and Dyract layered with Spectrum-TPH (sandwich) in Class II restorations of permanent dentitions.
  
  
  METHODS
  23 adult patients aged 25-62 were selected at random in a general dental practice. Each patient had 3 bicuspid teeth restored with Dyract, Spectrum-TPH and a "sandwiched" combination where Dyract was covered by the composite resin TPH. During the entire study, three patients were lost. Restorations were clinically evaluated using a modified Ryge/USPHS system.
  
  
  RESULTS
  Over 36 months all three types of restorations performed well clinically. No post-operative sensitivity was reported by any patient indicating proper bonding and sealing. Only one Dyract/TPH sandwich restoration had to be replaced after 2.5 years due to root caries. The Dyract restorations exhibited significantly higher (P = 0.0039) occlusal wear than the TPH and the Dyract/TPH sandwiched restorations. The marginal integrity was also found to be significantly better (P = 0.001) for the TPH and Dyract/TPH restorations compared to Dyract alone, while no significant difference (P > 0.05) could be demonstrated between TPH and Dyract/TPH restorations. The low rate of failure in the three different restorative systems suggests that they are reliable restorative materials in permanent bicuspids over a 3-year period.
authors.affiliation: Oral and Dental Research Institute, Faculty of Dentistry, University of Stellenbosch, Tygerberg, South Africa.
authors.forename: Martin
authors.initials: M
authors.lastname: Wucher
authors.forename: Sias R
authors.initials: SR
authors.lastname: Grobler
authors.forename: Petrus J C
authors.initials: PJ
authors.lastname: Senekal
mesh_terms: D000096:Acetone; D000328:Adult; D001641:Bicuspid; D016009:Chi-Square Distribution; D020770:Compomers; D003188:Composite Resins; D018772:Dental Marginal Adaptation; D019232:Dental Restoration Failure; D019554:Dental Restoration Wear; D003793:Dental Restoration, Permanent / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008689:Methacrylates; D008875:Middle Aged; D008963:Molar; D011109:Polymethacrylic Acids; D019279:Resin Cements; D017640:Silicates
chemical_list: D020770:Compomers; D003188:Composite Resins; C088486:Dyract; D008689:Methacrylates; D011109:Polymethacrylic Acids; D019279:Resin Cements; D017640:Silicates; C467914:TPH spectrum; C444444:prime and bond 2.1; D000096:Acetone