title: Fracture resistance and microtensile bond strength of maxillary premolars restored with two resin composite inlay systems.
abstract: OBJECTIVE
  To compare the in vitro fracture resistance and the microtensile bond strength (muTBS) of premolar teeth restored with two light-cured resin composite inlay systems.
  
  
  METHODS
  50 sound human maxillary premolars were divided randomly into five equal groups. Four groups received mesial-occlusal-distal (MOD) inlay preparations. Restorative treatments comprised: Group 1 (Renew direct resin composite), Group 2 (Renew direct resin composite inlay), Group 3 (Tescera indirect resin composite inlay), Group 4 (non-restored), Group 5 (intact). All teeth were loaded axially until fracture. The same resin-based materials as used in Groups 1-3 were bonded to the superficial coronal dentin of 15 teeth. Beams approximately 1.0 mm x 1.0 mm were prepared and tested in microtensile mode. Results were compared using one-way ANOVA and Tukey's multiple comparison tests.
  
  
  RESULTS
  Mean fracture strengths (KN): Group 1, 2.06 (0.76); Group 2, 2.30 (0.49); Group 3, 2.62 (0.68); Group 4, 1.24 (0.44); Group 5, 2.40 (0.71). Group 4 was significantly weaker that the other four groups, P < 0.01. Mean muTBSs (MPa): Group 1, 33.38 (6.24); Group 2, 20.38 (6.24); Group 3, 20.87 (4.62). Group 1 was significantly stronger than the other two groups, P < 0.01.
authors.affiliation: Institute of Stomatology, Nanjing Medical University, Nanjing, PR China.
authors.forename: Ya-Shou
authors.initials: YS
authors.lastname: Sun
authors.forename: Ya-Ming
authors.initials: YM
authors.lastname: Chen
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Smales
authors.forename: Kevin H K
authors.initials: KH
authors.lastname: Yip
mesh_terms: D000134:Acid Etching, Dental; D000537:Aluminum Oxide / Q000737:chemistry; D001641:Bicuspid / Q000503:physiopathology*; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000379:methods; D045662:Dental Etching; D019232:Dental Restoration Failure; D003804:Dentin / Q000503:physiopathology; D006801:Humans; D007284:Inlays; D008422:Materials Testing; D008437:Maxilla; D008689:Methacrylates / Q000737:chemistry; D013314:Stress, Mechanical; D013718:Tensile Strength; D014082:Tooth Fractures / Q000503:physiopathology*
chemical_list: D003188:Composite Resins; D008689:Methacrylates; C485364:Renew composite; C481143:TESCERA; D000537:Aluminum Oxide