MONITORING DEMINERALIZATION AND REMINERALIZATION OF ENAMEL IN-VITRO USING AN INFRARED REFLECTANCE METER

The aim of this study was to design and investigate the use of an inex pensive method of monitoring the progress of demineralisation and subs equent remineralisation in artificial carious lesions. A small infrare d (IR) reflectance meter was built which illuminated a 4 mm x 4 mm are a on the buccal surface of a tooth and measured the reflected IR inten sity. Repeated measurements were taken over a period of 25 days, durin g which the enamel surface was exposed to demineralising and subsequen tly remineralising solutions. Thirty-six teeth were studied under a va riety of de- and remineralising conditions. It was observed that the I R specular reflectance of the tooth surfaces decreased with time durin g lesion formation and increased with time during remineralisation. It is suggested that the decrease in IR specular reflectance during demi neralisation and the increase during remineralisation are a result of continuous changes in the crystals at the enamel surface during these processes.