Use Of Electric Caries Monitor In Early Detection And Prevention Of Root Caries: In Vitro And In Vivo Studies

Objectives: To assess the effect of ECM in monitoring demineralization and remineralization of root caries by comparing it with other histological methods; and in clinical trial use ECM to monitor reversal of root caries to compare the anti-caries effect of fluoride and non-fluoride dentifrice. Study 1. Materials and methods: Root surface specimens were randomly allocated into 4 groups: 5000ppm fluoride group, 1450ppm fluoride dentifrice group, 1100ppm fluoride dentifrice group and non-fluoride dentifrice control group. Root surfaces were demineralized and remineralized in pH cycling model. ECM (Lode Diagnostics BV, Groningen, the Netherlands) was used to measure electrical resistance on root surfaces. Calculate the area of root surface window area using a computerised image-analysis system. Analyse total calcium concentration in acid buffer using atomic absorption spectrometer. Use confocal laser scanning microscopy (CLSM) to quantify the mineral content before and after remineralization. Poralized light microscopy (PLM) was used to observe the morphological changes of the tissue slides after demineralization and remineralization. Results: Variation of Log10ECM after demineralization in 5000ppm group is significantly lower than those in other groups (P<0.05) . Calcium demineralisation rate in 5000ppm group issignificantly lower than those in other groups (PO.05 ) .Variation of LogioECM after remineralization in 5000ppm group is 1.76, which is significantly higher than other groups (P<0.05 )-, the corresponding figures in 1450ppm and HOOppm group are 1.07 and 1.02, there is no significant difference between them CP>0.05) . Results from CLSM support those of ECM. PLM observation showed in fluoride groups a banding or deposit of mineral appeared within the lesions of these specimens.Study 2. Materials and methods: Following baseline root caries examination, qualifying adult subjects from Chengdu area were randomized into two groups: 1450ppm fluoride dentifrice and non-fluoride dentifrice group. Examinations of root caries lesions were repeated after three months and six months. These examinations include ECM measurement, plaque index, cativation, gingival distance, lesion area and hardness. Results: 178 subjects completed six-month examination. After six months, the root caries lesions in 1450 ppm dentifrice group exhibited significant decreases in plaque. ECM measurement indicated significant mineralization of the root caries lesions by the 1450 ppm fluoride dentifrice, which was significantly greater than that in the non-fluoride control. 35.2% of the subjects who used the 1450 ppm fluoride dentifrice exhibited at least one root caries lesion which became hard, which was significantly greater than the corresponding 17.8% in non-fluoride group. Conclusions: ECM can be used in vitro to monitor mineral changes in root caeies. 1450ppm fluoride dentifrice is more effective in reversal of root caries than non-fluoride one. 5000ppm fluoride dentifrice has better effect in prohibit root demineralization and enhance remineralization.