title: Effect of glass inserts on resin composite wear.
abstract: OBJECTIVE
  To determine the in vitro wear resistance and microstructural stability of composites in which the beta quartz insert was used.
  
  
  METHODS
  Three different sized inserts were used in conjunction with P-50 and Herculite XR posterior resin composites. The study was designated to create varying gap dimensions between the insert and wall of the preparation (0.75, 1.25 and 1.50 mm). In addition, one half of the inserts contacted the dentin floor of the cavity whereas the other half rested on 1.0 mm of composite. The controls consisted of resin composite only. Using an in vitro wear testing device, all specimens were subjected to 400,000 cycles of masticatory loading. Upon completion of testing, profilometric tracings and SEM were used to determine relative wear, patterns of wear and microstructural changes. Differences, in wear values were analyzed by two-way ANOVA.
  
  
  RESULTS
  The wear values for P-50 and Herculite XR controls were 24.8 and 31.3 micrometers, respectively. No significant differences were detected (P<0.05) in amount of wear between the control specimens and the insert specimens, regardless of size. The same results were obtained regardless of whether the insert rested on dentin or resin composite. SEM evaluations however, revealed excellent interfacial continuity after wear testing. While the inserts did not influence the wear resistance, they may provide an excellent means for maintaining functional occlusion.
authors.affiliation: Department of Operative Dentistry, Osaka University Faculty of Dentistry, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kawai
authors.forename: K F
authors.initials: KF
authors.lastname: Leinfelder
mesh_terms: D000704:Analysis of Variance; D001641:Bicuspid; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002516:Ceramics; D003188:Composite Resins / Q000737:chemistry*; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent / Q000295:instrumentation* / Q000379:methods; D005898:Glass; D006801:Humans; D008409:Mastication; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008963:Molar; D011791:Quartz; D019279:Resin Cements; D013499:Surface Properties
chemical_list: C088834:Beta-Quartz glass-ceramic; D003188:Composite Resins; D019279:Resin Cements; C065770:Herculite XR; C065771:P50 composite resin; D011791:Quartz; D017438:Bisphenol A-Glycidyl Methacrylate