酸蚀后不同时间应用两种牙膏对牙釉质再矿化和抗酸蚀的效果

Effects of two toothpastes used at different time on enamel remineralization and acid resistance

背景:多数学者建议食用酸性食物30 min以后刷牙,以减少牙齿磨损,但不同时间应用牙膏制剂再矿化的效果差异研究较少。目的:比较在酸蚀后即刻和酸蚀后唾液浸泡30 min应用生物活性玻璃牙膏或含氟牙膏,对酸蚀牙釉质再矿化和再矿化后抗酸蚀的影响。方法:取50个牛牙釉质样本,经碳酸饮料酸蚀后随机分为5组进行再矿化实验,空白对照组置于天然唾液中30 min;即刻含氟组和即刻生物活性玻璃组分别立即涂抹含氟牙膏浆和生物活性玻璃牙膏浆,然后置于天然唾液中30 min;30 min后含氟牙膏组和30 min后生物活性玻璃组置于天然唾液中30 min后,再分别涂抹含氟牙膏浆和生物活性玻璃牙膏浆;再矿化实验后,将各组样本再次经碳酸饮料酸蚀。再矿化实验与再酸蚀实验后,检测各组样本表面显微硬度,并进行扫描电镜观察。结果与结论:(1)再矿化实验后,各组表面显微硬度值均高于空白对照组(P <0.05),生物活性玻璃组表面显微硬度值高于含氟组(P <0.05),30 min后含氟牙膏组表面显微硬度值高于即刻含氟组(P <0.05);(2)再酸蚀实验后,各组表面显微硬度值降低幅度均低于空白对照组(P <0.05),生物活性玻璃组表面显微硬度值降低幅度低于含氟组(P <0.05);(3)再矿化及再酸蚀实验后,空白对照组釉柱间质破坏最严重,间质表面较釉柱明显降低;生物活性玻璃组表面最为平坦,釉柱与釉柱间质破坏最小,表面可见有大量球形颗粒附着;(4)结果表明,生物活性玻璃可有效增强酸蚀牙釉质再矿化及抗酸蚀效果,酸蚀后即刻应用含氟牙膏减少其再矿化;酸蚀后即刻和酸蚀后唾液浸泡30 min应用生物活性玻璃牙膏对釉质再矿化和抗酸蚀的效果无差异。

BACKGROUND:Tooth brushing to reduce tooth wear is mostly recommended at 30 minutes after eating acidic food.However,little is reported on the effect of toothpastes used at different time on enamel remineralization.OBJECTIVE:To evaluate the effect of bioactive glass toothpaste or fluoride toothpaste on enamel remineralization and acid resistance after remineralization when used instantly after being eroded or 30 minutes after being eroded.METHODS:Fifty bovine enamel samples were randomly divided into five groups after the acid etching of carbonated beverage.The blank control group was placed in the natural saliva for 30 minutes.Instant fluoride group and instant bioactive glass group were immediately smeared with fluoride toothpaste and bioactive glass toothpaste,respectively,and then the samples in these two groups were placed in the natural saliva for 30 minutes.Groups of fluoride toothpaste or bioactive glass used at 30 minutes after acid etching were placed in the natural saliva for 30 minutes,and then the fluoride toothpaste or the bioactive glass toothpaste paste was applied respectively.After remineralization,all the samples were re-etched by carbonated beverages.After remineralization and re-etching,the surface microhardness of each sample was detected and observed by scanning electron microscope.RESULTS AND CONCLUSION:(1)After remineralization,the surface microhardness of each group was higher than that in the blank control group(P<0.05).The surface microhardness of the bioactive glass groups was higher than that in the fluoride groups(P<0.05).The surface microhardness of the group with fluoride toothpaste used at 30 minutes after acid etching was higher than that in the instant fluorine group(P<0.05).(2)After re-etching,the decrease in the surface microhardness was lower in the treatment groups than the blank control group(P<0.05),and the decrease in the surface microhardness in the bioactive glass groups was lower than that in the fluoride groups(P<0.05).(3)After remineralization and re-etching,most serious damage to the interprismatic substance was found in the blank control group,and the surface of the interprismatic substance was obviously lower than that of the enamel prisms.The flattest surface of the interprismatic substance in the bioactive glass groups was observed,and there was a minimal damage to the interprismatic substance and the enamel prisms.Moreover,a large number of spherical particles were attached to the surface of the interprismatic substance in the bioactive glass groups.To conclude,these results show that the bioactive glass can effectively enhance the remineralization and anti-corrosion ability of the etched enamel.The use of fluoride toothpaste instantly after acid etching can reduce the enamel remineralization.Moreover,there is no difference in enamel remineralization and acid resistance using bioactive glass instantly or 30 minutes after immersion in the natural saliva.