An Comparative Study On Prevention Effect Of Enamel Remineralization Between Infiltrating Resin And Fluoride Agent

Objective:The purpose of this study was to compare the demineralization depth after demineralization,and evaluate the ability of preventing and treating the demineralization of teeth with penetrating resin and fluoride protective agent by observing the surface morphology and roughness of demineralized enamel treated with penetrating resin and fluoride protective agent,therefore to provide theoretical basis for the effectiveness of penetrating resin in early caries treatment and provide evidences for its clinical use in the future.Methods: Experiment 1:The fresh first premolar extracted from the maxillofacial surgery clinic of Tianjin Medical University Dental Hospital was collected to remove the residual calculus and soft tissue on the tooth surface.The 4mm×4mm×2mm enamel block was taken from the buccal side of the crown with a slow disk-shaped emery sheet and cooled by water spray.The buccal enamel was used as the experimental area,and the surfaces and teeth were polished with 600#、1000#、1200#、2000# carborundum water sandpaper.The polishing cup is made of rubber to make it a smooth surface,which is convenient for observation by atomic force microscope.Put it into the ultrasonic cleaning machine to clean and remove the debris generated by surface grinding.The samples were randomly divided into 4 groups,10 in each group.The test area was coated with anti acid nail polish separately.The experimental area was treated as follows: The control group(group A): no further treatment;Demineralization group(group B): demineralization in artificial carious demineralization solution;Infiltrating resin group(group C): after being demineralized in the artificial carious demineralization fluid,then treated with infiltrating resin according to the operation instructions;The fluorine protection agent group(group D): placed in the artificial caries demineralization.After demineralization in the liquid,fluorine protectant shall be used for treatment according to the operation instructions.After drying,the color of enamel surface was observed by naked eyes,and the surface morphology and roughness of experimental area were observed by AFM.Experiment 2:The fresh first premolars extracted from the maxillofacial surgery clinic of Tianjin Medical University Dental Hospital were collected to remove the residual calculus and soft tissue on the tooth surface.The buccal surface was polished with 600#、1000#、1200#、2000# carborundum water sandpaper,and the teeth were polished with rubber polishing cup,and then cleaned in an ultrasonic cleaner to remove the debris produced by the surface grinding.The 3mm×3mm fenestration area was drawn in the center of the cheek as an experimental area.The anti acid nail polish was smeared outside the fenestration area.The experimental teeth were demineralized in the artificial caries demineralization fluid for 21 days,and the enamel demineralization model was prepared.The samples after demineralization were randomly divided into 4 groups,10 in each group.The experimental areas were treated as follows: The first demineralization group(group A): coating two layers of nail polish;The two demineralization group(group B): without any treatment;Infiltrating resin group(group C): using infiltrating resin for treatment according to the operation instructions;Fluorine protection agent group(group D): according to the operation instructions,fluorine protectant was used for treatment.The experimental teeth were placed in the artificial caries demineralization solution again for 21 days to make grinding plates,stained with ethanol containing fluorescein sodium,and observed under the laser confocal microscope to measure the demineralization depth.The data were analyzed by SPSS 20.0 software package.One-way ANOVA was used to analyze the significances of microleakage among four groups,P value is <0.05,was considered as significance statistically.Results:1.The values of Ra and Rq in infiltrating resin group and the fluorine protection agent group were significantly higher than those of normal enamel group,and the difference was statistically significant(P<0.05).There was no significant difference between the two groups in Ra and Rq values(P>0.05).2.The depth of the second demineralization in the infiltrating resin group was much smaller than that in the fluorine protection agent group after treatment of demineralized enamel by infiltrating resin and fluorine protection agent respectively,and the difference was statistically significant(P<0.05).Conclusions:1.The tooth surface roughness after the treatment of infiltrating resin and fluorine protection agent is similar,which is obviously larger than that of normal enamel,and is better than that of demineralized group.It is recommended that the surface of the tooth be polished after the treatment of infiltrating resin to reduce the roughness of the tooth surface and prevent remineralization.Considering that polishing may affect the effect of fluorine protection agent,the feasibility of the operation needs further study.2.Both the infiltrating resin and the fluorine protection agent have the ability to prevent tooth remineralization,and the effect of infiltrating resin is obviously better than that of fluorine protection agent,which indicates that the ability of infiltrating resin to prevent tooth secondary demineralization is better than that of fluorine protection agent.