title: Thermal variations in the pulp chamber associated with composite insertion techniques and light-curing methods.
abstract: OBJECTIVE
  The aim of this study was to investigate the effect of different incremental insertion techniques, photoactivation, and restorative phases on thermal variations occurring during the polymerization of Filtek Z250 composite resin.
  
  
  METHODS
  The experiment was conducted using 90 bovine incisor teeth. The teeth were randomly assigned to three groups according to the technique used for photoactivation with a halogen light (continuous, soft-start, or intermittent). The groups were further separated into three subgroups according to method of increment placement (bulk, oblique, or horizontal/vertical) for a total of nine groups (n=10). Restorations were placed in a controlled environment (37 masculineC and 50+/-10% RU) and the temperature recorded using a digital thermometer coupled to a Type-K thermocouple inserted in the pulp chamber through the root canal in contact with the dentin. Data were analyzed using an analysis of variance (ANOVA) and the Tukey's test.
  
  
  RESULTS
  Higher temperature values were found for continuous light photoactivation in combination with the placement of horizontal/vertical composite increments and photoactivation of the adhesive using a continuous light exposure.
  
  
  CONCLUSIONS
  The light source is the most important factor producing temperature changes during photoactivation of resin composite.
  
  
  CONCLUSIONS
  Temperature increases in the pulp chamber due to light curing should be considered to avoid harming the delicate pulp tissue when large restorations or inlays/onlays require several consecutive light curing exposures for a complete cure.
authors.affiliation: Department of Restorative Dentistry, Piracicaba School of Dentistry, State University of Campinas (UNICAMP), Piracicaba, SP, Brazil. rickdanil@fop.unicamp.br
authors.forename: Ricardo Danil
authors.initials: RD
authors.lastname: Guiraldo
authors.forename: Simonides
authors.initials: S
authors.lastname: Consani
authors.forename: Mario Alexandre Coelho
authors.initials: MA
authors.lastname: Sinhoreti
authors.forename: Lourenco
authors.initials: L
authors.lastname: Correr-Sobrinho
authors.forename: Luis Felipe Jochims
authors.initials: LF
authors.lastname: Schneider
mesh_terms: D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000528:radiation effects; D001831:Body Temperature; D002417:Cattle; D003188:Composite Resins / Q000528:radiation effects; D055117:Curing Lights, Dental; D003782:Dental Pulp / Q000502:physiology*; D003793:Dental Restoration, Permanent / Q000379:methods*; D006219:Halogens; D055115:Light-Curing of Dental Adhesives / Q000379:methods*; D011897:Random Allocation; D019279:Resin Cements / Q000528:radiation effects
chemical_list: D003188:Composite Resins; C444701:Filtek Z250; D006219:Halogens; D019279:Resin Cements; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate