title: Pulp Chamber Heating: An In Vitro Study Evaluating Different Light Sources and Resin Composite Layers.
abstract: The aim of the present in vitro study was to evaluate the temperature variation inside the pulp chamber during light-activation of the adhesive and resin composite layers with different light sources. Cavities measuring 8x10 mm were prepared on the buccal surface of bovine incisors, leaving a remaining dentin thickness of 1 mm. Specimens were placed in a 37±1 °C water bath to standardize the temperature. The temperature in the pulp chamber was measured every 10 s during 40 s of light activation of the adhesive system (SBMP-3M/ESPE) and in the three consecutive 1-mm-thick layers of resin composite (Z250-3M/ESPE). Three light source devices were evaluated: Elipar 2500 (QTH), LD Max (LED low irradiance) and VALO (LED high irradiance). The results were submitted to one-way ANOVA with repeated measures and Tukey's test, both with p<0.001. The exothermic reaction warming was observed in the Z250 increments, but not in the SBMP. The high irradiance LED showed a higher temperature average (42.7±1.56 °C), followed by the quartz-tungsten-halogen light (40.6±0.67 °C) and the lower irradiance LED (37.8±0.12 °C). Higher temperature increases were observed with the adhesive and the first resin composite increment light-activation, regardless of the employed light source. From the second increment of Z250, the restorative material acted as a dispersive structure of heat, reducing temperature increases. Regardless the light source and restorative step, the temperature increased with the irradiation time. It may be concluded that the light source, irradiation time and resin composite thickness interfered in the temperature variation inside the pulp chamber.
authors.affiliation: Department of Operative Dentistry, Endodotics and Dental Materials, Bauru Dental School, USP - Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: Lígia Maria Lima
authors.initials: LM
authors.lastname: Andreatta
authors.affiliation: Department of Operative Dentistry, Endodotics and Dental Materials, Bauru Dental School, USP - Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: Adilson Yoshio
authors.initials: AY
authors.lastname: Furuse
authors.affiliation: Department of Clinical Sciences (Restorative), Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.
authors.forename: Anuradha
authors.initials: A
authors.lastname: Prakki
authors.affiliation: Department of Operative Dentistry, Endodotics and Dental Materials, Bauru Dental School, USP - Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: Juliana Fraga Soares
authors.initials: JF
authors.lastname: Bombonatti
authors.affiliation: Department of Operative Dentistry, Endodotics and Dental Materials, Bauru Dental School, USP - Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: Rafael Francisco Lia
authors.initials: RF
authors.lastname: Mondelli
mesh_terms: D000818:Animals; D002417:Cattle; D003188:Composite Resins; D003786:Dental Pulp Cavity; D066298:In Vitro Techniques; D008027:Light; D013696:Temperature
chemical_list: D003188:Composite Resins