REGRESSION OF WHITE SPOT ENAMEL LESIONS - A NEW OPTICAL METHOD FOR QUANTITATIVE LONGITUDINAL EVALUATION IN-VIVO

This article describes a new nondestructive optical method for evaluat ion of lesion regression in vivo. White spot caries lesions were induc ed with orthodontic bands in two vital premolars of seven patients. Th e teeth were banded for 4 weeks with special orthodontic bands that al lowed plaque accumulation on the buccal surface. The teeth were left i n the dentition for 2 or 4 weeks after debanding. Regular oral hygiene with a nonfluoridated toothpaste was applied during the entire experi mental period. The optical scattering coefficient of the banded area w as measured before banding and in 1-week intervals thereafter. The sca ttering coefficient returned to the sound value in an exponential mann er, the half-value-time for left teeth being 1.1 week, for right teeth 1.8 weeks, these values being significantly inequal (p = 0.035). At t he start of the regression period, the scattering coefficient of left teeth lesions was 2.5 as high as of right teeth lesions, values being inequal with p = 0.09. It is concluded that regression of initial lesi ons in the presence of saliva is a relatively rapid process. The new o ptical method may be of clinical importance for quantitative evaluatio n of enamel lesion regression developed during fixed appliance therapy .