The Clinical And Experimental Research On Effects Of Two Different Concertrations Fluor Protectors To Prevent Caries

Background:Dental caries is a kind of chronic destruction on dental hard tissue which is related to multiple factors including bacteriam etc. Fluoride can prevent dental caries and it has been applied since the 20th century.Many techniques of dental caries prevention with fluoride recommended by WHO and oral authorities of many countries have been worldwide applied now and have made enormous social effect and great economic return.Although their effect on preventing dental caries is confirmed,we found many problems applying fluoride products.High concentrations fluoride would lead to acute and chronic fluoride poisoning or dental fluorosis;Dental caries of primary teeth is one of the common oral diseases in children and there are many problems about local fluoride application,such as worse binding ability to tooth surface,transient remaining time in oral cavity and inconvinent to use in large scale.Fluor protector is one technique of local fluorides and application and two different concentrations(0.1% and 0.5%) are commonly used.Many researches on the effect of fluoride protector on preventing dental caries were carried out in our country and abroad.Most of them were focused on clinical and laboratory tests of permanent teeth. No researches about the effect of fluor protector on preventing dental caries of primary teeth are reported, researches about the safety of fluor protector on primary teeth,also are not reported.So it is necessary to investigate the fluor protector effect on preventing dental caries systematically.Objective:The objections of this study are to invertigate the effect of fluoride protector on enamel solubility and remineralization,and to compare the caries prevention effects of the fluor protectors with two different concentrations.The safety of fluor protector application in children is also studied to provide reliable theory about fluoride appliction in large scale population.Methods:1. Study on effect of two different concentrations fluor protectors on resist-acid function of primary tooth enamel.20 non-carious primary tooth enamels were randomly divided into four groups with 5 samples in each groups.0.5% fluor protectors and 0.1%fluor protectors were applied to the experiment groups,while 0.5% Sodium fluoride and deionizer water were applied to the control groups.Then they had been dematerialized for 48 hours,the amounts of phosphorus and calcium dissolved in the acid solution were determined by atomic absorption spectrophotometer and ultraviolet sperctrophotometer respectively.Then we will compare the resist-acid function of two different concentrations fluor protectors.2. Clinical research of two different concentrations fluor protectors preventing dental caries of primary teeth.200 children were randomly chose from one of nurseries of Chongqing,and were randomly divided into four groups as 0.5% fluor protectors,0.1% fluor protectors,0.5% Sodium fluoride and deionizer.Fluoride were applied every half an year and the research has lasted for two year.The research was designed by two-blinded methods, and was carried out with WHO dental caries standard.All the data has been collected to explore the dental caries preventing effect of two different concentrations fluor protectors.3. Urine fluorine monitoring.20 children were randomly chose and randomly divided into three groups with 10 children in 0.5% fluor protectors group and 5 children in other two groups:0.5% fluor protectors were applied as experiment group,while 0.5% Sodium fluoride and deionizer water were applied to the control groups.Their urine were collected before fluor protector had been applied and 24 hours and 48 hours after it.The urine fluorine concentrations were determined by fluorine electrode to explore the safety of applying fluor protectors.Results:1.Two different concentrations fluor protectors were effective on resist-acid function of primary teeth enamel.There is no significant difference between two experiment groups.2.0.5% fluor protector group were effective on dental caries of primary teeth.And there is significant difference between the group and the other groups.3.There is no significant difference between all the groups,and there is no significant difference between any group of different time section. Conclusion:Two different concentrations fluoride protectors could decrease enamel solubility and promote enamel remineralization;0.5% fluor protector could be effective on prevent dental caries of primary teeth;and the urine fluorine of the fluor protectors is regular. So,two different concentrations fluor protectors were effective in preventing dental caries of primary teeth,and 0.5% concentration is the better one,and the fluor protectors were safe.