Analysis of the effect of thickness and irradiance on polymerization delay and initial rate in light-cured resin filling materials

Polymerization onset delay is a fundamental expectation when inhibitors are present in light-curing polymer systems. This has a bearing on the completeness of the cure obtained under some exposure circumstances. Photo-polymerization theory needs to be revisited to accommodate products such as those tested here that show a non-classical reaction rate exponent. Numerical models of DC development with exposure time must necessarily account for the onset delay of polymerization, while also accommodating the effects of variation in attenuation coefficient during curing and over depth. Data must be collected at a high rate when using high-irradiance and thin test piece conditions.