| Objectives:To get the new date about caries of 3 years old preschool children using ICDAS ?and DIAGNOdent. To monitor the caries process along with fluoride varnish application in 3 years old preschool children using ICDAS ? and DIAGNOdent and estimate the value of the two methods in evaluating the function of caries prevention technique or material. To analyze the correlation between DIAGNOdent and ICDAS ?, and discuss the validity of DIAGNOdent in detecting caries on primary teeth.Methods:Three years old preschool children conformed to the inclusion criteria and exclusion criteria were recruited from a kindergarten in Xi'an Xincheng community using cluster sampling method. Occlusal surface (O), 1/3 of the gingival side of buccal surface (GB),2/3 of the occlusal side of buccal surface (OB) of teeth 54,64, 74,84 and 1/3 of the gingival side of labial surface (GL) and 2/3 of the incisor of labial surface (IL) of teeth 51 and 71 were detected using ICDAS II and DIAGNOdent methods. D1-6, D1-3 and D4-6 were three kinds of criteria for ICDAS II and health (Do), mild demineralization (D1) and severe demineralization (D2) for DIAGNOdent. Descriptive analysis was used to show the caries prevalence of different sites. Chi-square test was used to compare caries rate of different sites.Three years old preschool children conformed to the inclusion criteria and exclusion criteria were recruited from a kindergarten in Xi'an Xincheng community using cluster sampling method. Then the subjects were randomly divided into two groups. One group used Duraphat fluoride varnish (group DP) and another group used Fluor Protector (group FP). Follow-up detections were made at baseline, 3 months, 6 months and 12 months using two kinds of detection methods above. Friedman test and Wilcoxon test were used to compare differences in one group. The Mann - Whitney U test was used to compare differences between groups. Chi-square test was used to compare caries rate of different interval times.Date obtained from four visit times was used. Spearman rank correlation analysis was used to detect the correlation between the two methods. ROC curve was used to detect the accuracy of DIAGNOdent for detecting caries.Results:1. Caries of different sites detected with ICDAS ?A total of 164 children were included. The proportions of code 1, code 2, code 3,code 4, code 5 and code 6 were 75.2%, 13.3%, 5.7%, 3.0%, 0.8%, 1.8% and 0.2%. The proportions of code 1, code 2 and code 3 were higher than those of code 4, code 5 and code 6. This suggested that enamel caries was major in 3 years old children.The caries rates of different sites were compared. The caries rates of site O, site GB,site OB, site GL and site IL were 44.5%, 27.4%, 14%, 17% and 9.8%. The caries rate of site O was higher than that of other sites (P<0.05). The caries rate of site GB was higher than that of site GL. The caries rate of site OB was higher than that of site IL. And the caries rate of buccal cervical was higher than that of incisal. This suggested that occlusal and buccal cervical surfaces were the predilection sites in 3 years old children.The ratios of enamel caries and dentin caries were compared. On site O, the ratios of enamel caries and dentin caries were 36.0% and 8.5% respectively, and the former was higher than the latter significantly(P<0.05). The ratio of enamel caries was higher than that of dentin caries on other four sites significantly (P<0.05). This could identify that the enamel caries was major in 3years old children, and ICDAS ? has the ability to detect early caries.The caries rates of one site using D1-6 and D4-6 two standards were compared. On all sites, the caries rate detected using D1-6 standard was higher than that when using D4-6 statistically (P<0.05). This suggested that ICDAS ? could detect caries more perfectly than WHO method.2. Caries of different sites detected with DIAGNOdentA total of 164 children were included. The caries rates of site O, site GB, site OB,site GL and site IL were 36.0%, 21.8%, 16.6%, 11.9% and 11.9%. The caries rate of site O was higher than that of other sites (P<0.05). The caries rate of site GB was higher than that of site GL. The caries rate of site OB was higher than that of site IL. The results were similar to ICDAS ? and suggested that occlusal surface was the predilection site in 3 years old children and the caries rate of primary molar was higher than that of incisor.On site O, the ratios of Di and D2 were 17.1% and 18.9%. This suggested that the ratio of strong demineralization was higher than beginning demineralization, but there was no statistical difference between them (P>0.05). But on other smooth surfaces, the ratio of beginning demineralization was higher than strong demineralization. This suggested that the caries on occlusal surface progressed into strong demineralization more easily.3. Monitoring of caries under fluoride varnish application using ICDAS ? and DIAGNOdentA total of 120 children were included, and 101 children finished all four visits. The mean of ICDAS ? codes at different times were compared. In addition to the site OB,there were no significant differences of ICDAS ? codes between the two groups at 12 mon (P>0.05). This suggested that the functions of the two kinds of fluoride vanish were similar. On site O, the means of ICDAS ? codes increased at 3 mon and decreased at 6 mon. But the means increased significantly at 12 mon (P<0.05) in both two groups. This suggested that only fluoride varnish cannot arrest the caries progress in pit and fissure and other measures also are needed. On smooth surfaces, the means of ICDAS ? codes decreased at 3 mon, 6 mon and 12 mon in both two groups and this phenomenon was more obvious in group DP. This suggested that remineralization on smooth surfaces could be received by means of using fluoride varnish twice one year. But on site IL, the means of ICDAS ? codes increased apparently at 12 mon. The caries on proximal surface may be responsible for the caries increase on incisor sites.The changes of caries rates at different times were compared using different ICDAS? criteria. When D1-6 criterion was used, the caries rates of site O at 3mon and 12mon were higher than that at baseline,but there were no statistical differences between them(P>0.05). The caries rates of smooth surfaces at all interval times were lower than that at baseline statistically (P<0.05) in group DP. In group FP, the caries rates of site O at 3mon and 12mon were higher than that at baseline, but there was no statistical difference between them (P>0.05). The caries rates of smooth surfaces at all interval times were lower than that at baseline. This suggested that caries on occlusal surface could be inhibited under the effect of fluoride varnish and caries on smooth surfaces could be remineralized. When D4-6 criterion was used, the caries rates of site 0 at three interval times were higher than that at baseline. And the caries rates of other smooth surfaces did not changed obviously in both two groups. When D1-3 criterion was used, the variation trends of caries rates were similar with D1-6 criterion. This suggested that the prevention effect of fluoride varnish is mainly on enamel caries. D1-6 criterion could reflect the changes of caries rate more objectively than D4-6 criterion.The changes of different ICDAS ? codes were also analyzed. On site O, the ratio of code 1 reduced and code 2 increased. The changes of other codes ratio were not significant. This suggested that the caries on occlusal surfaces progressed even under fluoride varnish application. On site GB, the ratios of code 1 and 2 decreased and code 0 increased significantly in group DP (P<0.05). This reflected the remineralizaion process on this site. In group FP, the ratio of code 1 decreased significantly at 12mon and code 0 increased. This also reflected the remineralization process. On other three sites, the ratios of code 1 and 2 decreased and code 0 increased. This suggested that the demineralization effect of fluoride varnish on smooth surfaces were perfect.The mean of DIAGNOdent at different interval times were compared. There were no significant differences between the two groups on all sites at 12 mon (P>0.05). This suggested that the functions of the two kinds of fluoride vanish were similar in one year.On site O, the mean of DIAGNOdent values rose continuously at 3 mon, 6 mon and 12 mon in group DP. In group FP, the mean of DIAGNOdent values rose at 3 mon and decreased at 6 mon significantly (P<0.05). Then the mean increased at 12 mon and were higher than that of baseline. This suggested that the effect of using fluoride varnish only was poor on fissure surface. On smooth surfaces, the mean of DIAGNOdent values dropped at 3 mon and 6 mon and increased at 12 mon in group DP. The mean of 12 mon was lower than that of baseline. In group FP, the mean of DIAGNOdent values rose at 3 mon and decreased at 6 mon significantly (P<0.05). Then the mean increased at 12 mon and were higher than that of baseline. The date suggested that the local application of fluoride varnish can arrest the progress of caries and promote the remineralization on smooth surfaces.The changes of different caries degrees were analyzed. On site O, the ratio of Do decreased gradually and ratio of D2 increased significantly. The ratio of D1 did not changed apparently in group DP. In group FP, the ratio of Do decreased and ratio of D2 increased at 3 mon and 12 mon. This suggested that the caries on occlusal surfaces progressed even under the effect of fluoride varnish. On other four sites, the ratio of Do increased and D1 and D2 decreased but these changes were nor apparently. This also suggested that the caries on smooth surfaces could be remineralized to some extent. At the same time, the date revealed that DIAGNOdent could not distinguish the cavity extent of caries.4. Correlation analysis between ICDAS ? and DIAGNOdentOn occlusal surface,when the results of ICDAS ? were 0,1,2, 3, 4, 5 and 6, the corresponding DIAGNOdent medians (interquartile ranges) were 6 (4-9), 10 (6 to 18), 16(9-26), 34 (18-64), 50 (28-99), 99 (85-99) and 85 (99-99) respectively. On smooth surface,when the results of ICDAS ? were 0, 1,2, 3, 4, 5, and 6, the corresponding DIAGNOdent medians (interquartile ranges) were 3 (2-5), 5 (3-9), 7 (4-12), 41.5 (8.75 71.5), 57 (32-71),99 (71-99) and 71 (99-99).On occlusal surface, the sites diagnosed with D0 using DIAGNOdent accounted for 85.3 percent of the sites diagnosed with code 0 using ICDAS ?. The sites of demineralization detected with DIAGNOdent accounted for 43.2 percent of the sites diagnosed with code 1 using ICDAS ?. Among the sites diagnosed with code 2, there were 39.8 percent were diagnosed with D0 using DIAGNOdent. When the ICDAS ?diagnostic code was 3, the proportion of D2 using DIAGNOdent was 61.4% and when the ICDAS ? cedes were 4-6, the proportion was 91.2%. The correlation coefficient between ICDAS ? and DIAGNOdent was 0.763 using Spearman rank correlation analysis. ROC curve was made to detect the ability of DIAGNOdent in diagnosing demineralization and dentin caries using ICDAS ? as the standard. On occlusal surface, the area under the ROC curve was 0.770 and the diagnostic value was moderate when the demineralization surface was detected. When the caries developed into dentin, the area under the ROC curve was 0.957 and the diagnostic value was higher. The cut-offs of demineralization surface and dentine caries were 9 and 23 respectively.On smooth surface, the sites diagnosed with D0 using DIAGNOdent accounted for 91.5 percent of the sites diagnosed with code 0 using ICDAS ?. The sites of demineralization detected with DIAGNOdent accounted for only 29.0 percent of the sites diagnosed with code 1 using ICDAS ?. When the ICDAS ? code was 2, the proportion of demineralization using DIAGNOdent was 46.8%. When the ICDAS ? diagnostic code was 3, the proportion of D2 using DIAGNOdent was 70% and when the ICDAS ? cedes were 4-6, the proportion was 94%. The correlation coefficient of the two methods was 0.815 on smooth surface. On smooth surface, the area under the ROC curve was 0.725 when demineralized caries was detected and 0.983 when dentin caries was detected. The cut-offs for demineralization surface and dentine caries were 5 and 19 respectively.Conclusions:1. ICDAS ? has the ability to detect demineralization surface and early enamel caries and then targeted preventive measures could be made according to the ICDAS results. Rates of occlusal and buccal cervical caries are higher than that of other sites. And early enamel caries is the major type in 3 years old children. So preventive measures are dominating in 3 years old children and occlusal surface is priority.2. DIAGNOdent also has the ability to detect early caries and provide reference for clinical practice. Occlusal caries rate is higher than that of other sites in 3 years old children and occlusal surface is easier to severe demineralization.3. Applying fluoride varnish twice a year has apparently preventive effect on primary teeth. It could inhibit the progress of occlusal caries and promote the remineralization process on smooth surfaces. The effect of fluoride varnish is mainly for enamel caries. ICDAS ? and DIAGNOdent could evaluate the effect of fluoride varnish in a short period. The changes of caries are discovered in only 3 mon while it will take 2 years when using WHO method. This can be an evidence for the two methods in testifying the effects of new technology and material.4. There is a certain correlation between DIAGNOdent and ICDAS ? indexes and the correlation coefficient on smooth surfaces is higher than that of occlusal surfaces. But the validity of DIAGNOdent in detecting early caries needs further research. When ICDAS ? index is used as a reference standard, the cut-offs of DIAGNOdent in detecting early caries and caries in dentin are both lower than cut-offs provided by direction. So DIAGNOdent method can only be used as an auxiliary in clinical and research works.The accuracy and cut-offs of DIAGNOdent in detecting caries need further research. |
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