title: Two-body wear resistance and degree of conversion of laboratory-processed composite materials.
abstract: OBJECTIVE
  The purpose of this investigation was to evaluate the relative 2-body abrasive wear and degree of conversion of 4 laboratory-processed composites (Targis, Concept, belleGlass, and Artglass) and 2 direct placement composites (Herculite and Heliomolar) after 7 days of storage.
  
  
  METHODS
  Human enamel was used as a positive control for 2-body abrasive wear, and 10 cylindric specimens (3.5-mm diameter, 8-mm height) of each material were prepared and stored in distilled water at 37 +/- 2 degrees C for wear testing. Relative 2-body abrasive wear rates were determined using a 30-micron diamond disk and a 2-body pin-on-disk apparatus. Subsequently, 3 polymerized specimens that had been stored in sealed polyethylene vials for 7 days were prepared for degree of conversion testing. The degree of conversion was determined on an infrared spectrometer using standard baseline techniques and various internal standards.
  
  
  RESULTS
  Statistical analysis using analysis of variance and the Tukey-Kramer multiple range test indicated significant differences between several of the materials tested for both 2-body abrasive wear and degree of conversion.
  
  
  CONCLUSIONS
  Concept exhibited significantly less 2-body abrasive wear compared to the direct and indirect composites (P < 0.01). Concept and belleGlass exhibited a mean degree of conversion that was significantly higher than any of the other composites tested (P < 0.01).
authors.affiliation: Section of Restorative Dentistry, Prosthodontics and Endodontics, Ohio State University College of Dentistry, Columbus, USA. knobloch.3@osu.edu
authors.forename: L A
authors.initials: LA
authors.lastname: Knobloch
authors.forename: R E
authors.initials: RE
authors.lastname: Kerby
authors.forename: R
authors.initials: R
authors.lastname: Seghi
authors.forename: M
authors.initials: M
authors.lastname: van Putten
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D019554:Dental Restoration Wear; D017276:Friction; D005899:Glass Ionomer Cements / Q000737:chemistry; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012823:Silicate Cement / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; C069352:Concept resin; D005899:Glass Ionomer Cements; C513708:Heliomolar; D008689:Methacrylates; D011140:Polyurethanes; D019279:Resin Cements; C110370:belleGlass; C111282:dental polyglass; C065770:Herculite XR; D012823:Silicate Cement