Patent ID: 7175436

Claim:
A radiometer for providing an indication of the exposure time needed to cause a light curable dental resin composite material to polymerize in response to the application of light from any type of dental light-curing source during the preparation of a dental restoration, said radiometer comprising: a sample holder of a size designed to hold a sample equivalent of said dental light curable resin composite material such that the thickness of the sample of light curable material in the sample holder will correspond to the depth of the resin composite material in said dental restoration; a solid state light sensor located in said radiometer in direct proximity to said sample of light curable material for generating an output in response to the exposure of said sample of light curable material to light from a dental light-curing source; a microprocessor programmed to respond to the output from said light sensor in accordance with an algorithm defining a mathematical model representative of the change in light transmission through said dental light curable composite material as a function of the extent to which said dental light curable composite material is being polymerized in response to such light and for generating an output signal when the polymerization of the sample has progressed with respect to time to a degree corresponding to a change in light transmission through the sample of less than a defined percent between 0.5% and 20%; and a time display that is responsive to the output signal generated from said microprocessor for displaying duration in time representing the amount of time needed to polymerize the dental light curable material in the dental restoration to its maximal extent.