摘要目的 研究单次饮用可口可乐对口内牙釉质的早期损害,为临床指导碳酸饮料的最低饮用量和饮用频率提供理论依据.方法 收集10颗下颌第三磨牙制备80个牙釉质样本块,随机区组化分成8组,每组10个釉质块.选取10名唾液分泌正常的健康志愿者,配戴含有样本牙块的腭托2h后,指导其在20 s内1次饮完100 ml可口可乐,测量酸蚀后第1、2、4、6、8、10、20及30 min时的表面显微硬度(surface microhardness,SMH).数据处理采用Kruskal-Wallis检验和Wilcoxon检验.结果 酸蚀后1、2、4、6、8、10、20及30 min组的显微硬度与酸蚀前相比均显著下降(P＜0.01),SMH变化百分比依次为(12.2±3.9)％、(16.8±5.5)％、(16.7±5.6)％、(16.2±6.2)％、(16.6±9.0)％、(15.6±3.7)％、(13.8±4.8)％和(11.4±3.2)％,2～8 min组和1 min组、30 min组之间差异有统计学意义(p值分别为0.029、0.008).结论 单次饮用100 ml可口可乐即可导致牙釉质SMH显著降低,启动牙釉质酸蚀.饮用后2～8 min内釉质表面的脱矿程度最严重,自然状态下30 min时牙釉质SMH无法完全恢复正常.

abstractsObjective Assessed the effect of single dose attack of Coca-Cola on early erosion and surface microhardness of permanent human enamel,in order to provide diet instructions on minimum amount and frequency of carbonated beverage consumption.Methods Eighty enamel slabs were prepared out of 10 extracted human mandibular third molars,and distributed into 8 groups with randomized block design(n=10).Ten generally healthy volunteers with normal saliva secretion wore acrylic palatal appliances containing 2 enamel slabs,with formation of a salivary pellicle 2 h ahead.The volunteers were instructed to drink 100 ml fresh Coca-Cola within 20 s.And then the alterations of the enamel slabs were measured using a Vicker's microhardness tester at 1,2,4,6,8,10,20 and 30 min after the consumption of Coca-Cola.For each volunteer,the experiment was carried out in four days,2 samples were examined each time.Data were analyzed using Kruskal-Wallis and Wilcoxon tests(α =0.05).Results Significant decreases in surface microhardness(SMH) were observed in each time point(P＜0.01).The percentages of surface microhardness changes on each exposure time were (12.2±3.9)％,(16.8±5.5)％,(16.7±5.6)％,(16.2±6.2)％,(16.6±9.0)％,(15.6±3.7)％,(13.8±4.8)％ and (11.4±3.2)％,respectively.Significant differences were observed between G1 min and G2-8 min(P=0.029),G2-8 min and G30 min(P=0.008).Conclusions Single intake of 100 ml Coca-Cola could lead to significant decrease of enamel microhardness and initiate erosion of enamel surface.Enamel surface microhardness decreased to the lowest points at 2-8 min,and began to recover after 10 min.The enamel surface microhardness could not fully recovered to the baseline level in 30 min if no intervention was performed.