title: The influence of occlusal finish line configuration on microleakage of indirect composite inlays.
abstract: OBJECTIVE
  The aim of this in vitro study was to evaluate the influence of occlusal finish line configuration on microleakage of indirect composite inlays.
  
  
  METHODS
  Forty-five recently extracted premolars were randomly assigned into three groups with different types of occlusal finish line preparations: bevel, chamfer, and butt joint. All restorations were made in Artglass (Heraeus Kulzer) and luted according to the manufacturer's recommendations. The teeth were sealed and then thermocycled 500 times between 5 degrees C and 55 degrees C. After that they were immersed in a 2% methylene blue (pH 7.2) solution for 24 hours. Each tooth was bisectioned in the buccal/lingual direction and then examined microscopically at each section to evaluate the microleakage score. The data were analyzed with chi-square and Fisher's Exact tests.
  
  
  RESULTS
  There were no significant differences between the buccal margins of maxillary premolars with occlusal bevel or butt joint; the chamfer had the worst performance. In the buccal margin of mandibular premolars, the bevel and chamfer showed significantly smaller amounts of leakage than the butt joint. No significant differences were observed between the three types of occlusal cavosurface preparations in the lingual margin of maxillary and mandibular premolars.
  
  
  CONCLUSIONS
  The finish line configuration, the position of the teeth in the arch, and the margin (buccal vs lingual) influenced microleakage. Whenever microleakage was observed in this study, it was always observed at the tooth-cement interface.
authors.affiliation: Department of Restorative Dentistry, Federal University of Minas Gerais, Belo Horizonte, Brazil. cunhapeixoto@terra.com.br
authors.forename: Rogéli Tibúrcio Ribeiro
authors.initials: RT
authors.lastname: Peixoto
authors.forename: Luiz Thadeu de Abreu
authors.initials: LT
authors.lastname: Poletto
authors.forename: Marcos Dias
authors.initials: MD
authors.lastname: Lanza
authors.forename: Vicente Tadeu Lopes
authors.initials: VT
authors.lastname: Buono
mesh_terms: D000134:Acid Etching, Dental; D001641:Bicuspid; D016009:Chi-Square Distribution; D004396:Coloring Agents; D003188:Composite Resins / Q000737:chemistry*; D003737:Dental Cavity Preparation / Q000145:classification; D003743:Dental Enamel / Q000648:ultrastructure*; D003763:Dental Leakage / Q000145:classification*; D018772:Dental Marginal Adaptation; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D007101:Immersion; D007284:Inlays; D008751:Methylene Blue; D019279:Resin Cements / Q000737:chemistry; D012823:Silicate Cement / Q000737:chemistry; D013223:Statistics as Topic; D013499:Surface Properties; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D004396:Coloring Agents; D003188:Composite Resins; D005899:Glass Ionomer Cements; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C111282:dental polyglass; D014867:Water; D012823:Silicate Cement; D008751:Methylene Blue