The temperature rise beneath a light-cured cement lining during light curing

Abstract

Isothermal differential thermal analysis has been used to measure the temperature rise at the lower surface of linings of a light-cured cement. It increases linearly with exposure time, and decreases linearly with lining thickness. Separating the end of the light guide from the surface of the lining results in a small reduction in temperature. The temperature rise accompanying setting (from the material alone) is not significant clinically, but the heat emitted from the light-curing unit presents a greater hazard. Whereas the heat produced by the source used in this study is acceptable, that generated by other sources can be greater and unacceptable. The difference in thermal diffusivity between the chemically cured and light-cured varieties of the cement tested (both when set) is not sufficient to produce a measurable difference for the temperature rise when an overlay of composite is light cured. The temperature rise depends more upon the depth of composite with the consequent adjustment to the curing time than upon the choice of composite product.