| Objectives: The objectives of this research are:1. To assess the effect of Quantitative Light-induced Fluorescence (QLF) in monitoring demineralization and remineralization of early caries on smooth surfaces by comparing it with other methods such as scanning electron microscope and confocal laser scanning microscope through bacteria models in vitro;2. To investigate the remineralized time of the early caries lesioris after using toothpaste through QLF system;3. Through comparing the different reversal of early caries induced by sodium fluoride, sodium monofluorophosphate and non-fluoride dentifrice in six months clinical trial to evaluate the capability of QLF for monitoring the reminearlization of lesions lengthways.There are three studies in this article.Study 1. Detection and prevention of early caries on smooth surfaces using QLF in vitroMaterials and methods: Enamel surface specimens were randomly allocated into 3 groups: 1450ppm sodium fluoride dentifrice group, 1450ppm sodium monofluorophosphate dentifrice group and non-fluoride dentifrice control group. Ten specimens were in each group. Sound enamel surfaces were demineralized and specimens with lesion were remineralized in bacteria model in vitro. QLF was used to analyze the area of lesions(Area), the loss of fluorescence(△F) and△Q (Area×△F) on enamel surfaces after demineralization and remineralization. Scanning electron microscope (SEM) was used to observe the morphological changes of the tissue slides and confocal laser scanning microscopy (CLSM) was used to quantify the mineral content after demineralization and remineralization.Results: 1. Early caries lesions were formed on the windows on smooth surfaces in different degree in bacteria model in vitro of three groups. Area,△F and△Q in non-fluoride dentifrice group were significantly higher than other two fluoride groups after demineralization(P＜0.05). No statistical difference was found between two fluoride groups(P＞0.05). Area,△F and△Q of the specimens with lesion changed a little after intervention in chemostat. There were no significant difference amongst the three groups(P＞0.05). 2. SEM observation showed obvious rough surface in non-fluoride dentifrice group after demineralization and obvious deposit of mineral in two fluoride dentifrice groups after remineralization. 3.Results from CLSM supported that area of the fluorescent lesion, total fluorescence and average fluorescent of the lesion in non-fluoride dentifrice group were higher than other two groups after demineralization(P＜0.05). There were no significantly statistical different amongst the three groups(P＞0.05) after remineralization. 4. The results of QLF and CLSM showed fine correlation after demineralization and remineralization(r＞0.70). QLF could reflect the changes of mineral content of caries lesions. Study 2. Detection of remineralized time of early caries on smooth surfaces using QLF in vivoMaterials and methods: Following baseline early caries examination, 24 school students (age from 11 to 14 years old) were qualified from Chengdu area. The subjects were randomized into two groups: 1450ppm sodium monofluorophosphate dentifrice group and non-fluoride dentifrice group. Oral health education and tooth-brushing training were instructed analogously to all subjects. QLF images of early caries lesions on smooth surfaces of the maxillary anterior teeth were taken at baseline and every week for eight times. The images were analyzed by the trained examiner with the area of lesion,△F and△Q.Results: Twenty-four subjects with 101 lesions completed this eight-week examination. During these eight weeks, the lesions on smooth surfaces got better in both two groups. The difference between the two groups had no statistical significance (P＞0.05). The judgment on the effects of two intervention studies could not be made in a short period (eight Weeks) using QLF system. Longer research time (more than 8 weeks) is needed When design a clinical trial using QLF as diagnostic methods. The remineralization of early lesion on smooth surface was found after three-week toothpaste application using QLF.Study 3. Detection and prevention of early caries on smooth surfaces using QLF in vivoMaterials and methods: Following baseline early caries examination, 305 school students (age from 11 to 14 years old) were qualified from Chengdu area. The schools in which the subjects studied were randomized into three groups: 1450ppm sodium fluoride dentifrice group, 1450ppm sodium monofluorophosphate dentifrice group and non-fluoride dentifrice group. Oral health education and tooth-brushing training were instructed analogously to all subjects. QLFimages of early lesions on smooth surfaces of the maxillary anterior teeth were taken at baseline, three and six months after the initiation of experiment. These images were analyzed by the trained examiner with the area of lesion,△F and△Q.Results: Two hundreds and ninety-six subjects completed this six-month examination. After three months, the lesions on smooth surfaces got better in all three groups. The area of the lesions became smaller. The mean of△F got lower and LG△Q decreased. The difference amongst three groups had no statistical significance (P＞0.05). After six months, the lesions on smooth surfaces also got better in all three groups than at baseline, 7 lesions of subjects disappeared in QLF images. Area of lesion,△F and AQ of the lesions in sodium fluoride and sodium monofluorophosphate dentifrice groups exhibited significant decreases than that of no-fluoride dentifrice group(P＜0.05). But no significantly difference was found between two fluoride dentifrice groups (P＞0.05).Conclusions: The mineral changes in early caries lesions, can be assayed by QLF in vitro. However, the result of which was uniform to that of CLSM. Through the QLF analyses in the six-month clinical trial, the similar effect was found that sodium fluoride and sodium monofluorophosphate dentifrice (F 1450ppm) in reversal of early caries other than non-fluoride one. As a diagnostic method which could quantify the miner content, QLF system had the capability of monitoring the variations of lesions lengthways. It also could assess the effects of different intervention studies. The current study assesses a new abbreviated caries clinical trial (aCCT) which involved fewer than 400 subjects and lasted six months. By employing a sensitive diagnostic system and the use of supervised brushing, this new aCCT design had reduced the number of subjects and duration of caries clinical trials. It should be worth using in this kind of studies in the future.
|
PDF Full Text Request