Influence of Ambient Light on Operation Time of Light-cured Resin Composite

Abstract

It is well known that ambient light such as room light or dental unit light hastens the polymerization of resin composite. When a cavity is complicated or large, the polymerization rate during the operating time is of particular concern. This phenomenon occurs because these light sources include the wavelengths that cure photo-polymerized resin composite. Of these two ambient light sources, dental unit light seems to have a larger influence because of its strong intensity. This study examined the influence of dental unit light on the polymerization rate of light-cured composites. The optical characteristics of dental light used in our department were measured, and the operating time for three kinds of resin composite was measured under the light of a typical unit used in our dental office. The results were as follows: 1. The illumination of dental light was 2 to 3 times the ISO standard. 2. Dental light included the wavelength band related to resin polymerization. 3. The operating time of rein composites used was remarkably shortened under dental light.