Temperature rises beneath resin composite restorations during curing.
OBJECTIVE
To compare the thermal conductivity of two different composite materials, with five light-cure units, in a series of different material thicknesses and light source distances.


METHODS
Two commonly used resin composite restorative materials and three light emitting diodes (LED), one halogen, and one plasma arc lights were selected. The thermal conductivity of the composite materials with different light curing units (LCU) was measured and compared. A K-type thermocouple and digital thermometer were used to assess the thermal conductivity. Materials depths of 1 mm, 2 mm and 4 mm and curing distances of 0 mm, 3 mm and 6 mm were compared. Four-way ANOVA was used to analyze the Ln transformation of the maximal temperature and a Tukey test for multiple comparisons.


RESULTS
Significant differences in temperature rise were observed between the two restorative materials. The thermal emission of the LED lights was higher than the other LCU's measured. An inverse ratio was found between material thickness and the measured thermal conductivity and the distance of the light tip from the restorative material.
Department of Oral Rehabilitation, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Ramat-Aviv 69948, Israel. matalons@post.tau.ac.il
Shlomo
S
Matalon
Hagay
H
Slutzky
Nadav
N
Wassersprung
Iris
I
Goldberg-Slutzky
Ariel
A
Ben-Amar
D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D055117:Curing Lights, Dental / Q000145:classification*; D003764:Dental Materials / Q000737:chemistry* / Q000528:radiation effects; D003793:Dental Restoration, Permanent / Q000295:instrumentation*; D006801:Humans; D008422:Materials Testing; D044367:Phase Transition; D058105:Polymerization; D013499:Surface Properties; D013696:Temperature; D013814:Thermal Conductivity; D013821:Thermometers; D013997:Time Factors; D044366:Transition Temperature
D003188:Composite Resins; D003764:Dental Materials; C474035:Filtek Supreme; C470230:Gradia