title: Temperature change and hardness with different resin composites and photo-activation methods.
abstract: This study verifies whether there is any temperature change during photoactivation of two resin composites (Filtek Z250 and Filtek Flow) with three different light curing methods (conventional halogen light curing unit, light emitting diodes curing unit and xenon plasma arc curing unit) and the relationship of temperature change with resin composite hardness. A type-K thermocouple registered the temperature rise peak in an elastomer mold during photoactivation. After photoactivation, the specimens were submitted to Knoop hardness test performed by an indenter (HMV-2000) under a load of 50g for 15 seconds. Both the temperature change data and results of the Knoop hardness test were submitted to ANOVA and Tukey's test at the 5% significance level. No statistical differences in temperature rise were recorded for the different composites following processing by light curing unit (p>0.05). The conventional halogen source produced statistically higher temperatures (p<0.05) than the other units. The plasma arc source promoted statistically lower (p<0.05) Knoop hardness values and temperature changes than the other light curing units.
authors.affiliation: Dental Materials, School of Dentistry of Piracicaba, State University of Campinas, Piracicaba, Brazil. schneider@fop.unicamp.br
authors.forename: Luis Felipe Jochims
authors.initials: LF
authors.lastname: Schneider
authors.forename: Simonides
authors.initials: S
authors.lastname: Consani
authors.forename: Mário Alexandre Coelho
authors.initials: MA
authors.lastname: Sinhoreti
authors.forename: Lourenço Correr
authors.initials: LC
authors.lastname: Sobrinho
authors.forename: Fábio Machado
authors.initials: FM
authors.lastname: Milan
mesh_terms: D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D006244:Hardness; D006801:Humans; D008027:Light; D008029:Lighting / Q000295:instrumentation / Q000379:methods*; D008422:Materials Testing; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013821:Thermometers
chemical_list: D003188:Composite Resins; C467913:Filtek Flow; C444701:Filtek Z250