Comparative Studies Of Fluoride-releasing Dental Materials And CPP-ACP In Enamel Remineralization

Objective:This study was conducted to compare the remineralizational efffectsbetwween fluoride-releasing dental materials and CPP-ACP, usingScanning Electron Microscopy(SEM) and Surface Micro Hardness(SMH). It is expected to provide the experiment results to clinicalpractice.Methods:Sixty premolars extracted before orthodontic treatment were prepared.Standard edgewise brackets with a slot size of0.018×0.025inches werebound on the clinical centres of the labial surfaces of the premolars, andthe other places were formed by nail vanish. A4mm×4mm window areawere formed in the demineralized buffer for2weeks. The sixty premolarswere randomly divided into five groups: Group A, no treatment; GroupB,CliproTX varnish; Group C, Clipro tooth creme; Group D, CPP-ACP;Group E, CPP-ACP+Clipro tooth creme. The remineralization of C,D,E Groups were arranged with a frequency of2times a day,5minutes everytime. Afterward, the samples were soaked into artificial saliva at37℃after the materials were washed off with distilled water. The dutation ofthe remineralization was8weeks, and at the end of the2nd,4th,6th and8th weeks, fifteen premolars were taken out. All the samples weredectected by SEM and SMH. The data were statistically analyzed usingSPSS13.0software.Results:1. SEM obvervation results: The hollows of the enamel surface could beseen in every group especially the control group which had the obvioushollows and the destroyed fibres. From the end of the2nd week, it couldbe seen that mineral substances deposited from B Group to E Group andthe demineralization holes changed smaller. There were moreremineralization mineral substances deposited in E Group than othergroups. B Group,C Group and D Group didn’t have much differencesbetween each other. At the end of the8th week, there were less obviousdemineralization holes in enamal surface of E Group, and enamel surfacefibres arranged regularly. A Group which was chalky presented alveolarchange and had obvious demineralization holes. The other groups hadremineralization and several minerals in the form of a small pelletdeposited. 2. SMH results: There were statistically significent differences(P<0.05) inenamel surface hardness between A Group and D, E Groups at the end of2nd week; At the end of the4th and6th weeks, a statistically significentdifferences in enamel surface hardness were found between A Group andthe other four groups. Between the E Group and the C Group significentdifferences in enamel surface hardness were registered. But at the end ofthe6th week, it could be found that between the B Group and C Groupthere were statistically significent differences (P<0.05) in enamel surfacehardness; There were significent differences between A Group and theother four groups and it was also clearly seen that there were statisticallysignificent differences(P<0.05) between E Group and B,C,D Groups atthe end of8th week.Conclusion:Fluoride-releasing dental materials and CPP-ACP can improve enamelremineralization and in vitro the effects are obvious.The effects ofCPP-ACP formed earlier than fluoride-releasing dental materials.Combining application of fluoride-releasing materials and CPP-ACP canstrengthen the effects.