【作者】 张勇；

【导师】 刘淑杰；

【作者基本信息】 中国医科大学 ， 口腔临床医学， 2002， 硕士

【摘要】 前言 Dean等人在早期的研究中，发现了氟与龋病之间的关系，肯定了氟化物的防龋作用。近年来，国内外对氟化物涂膜研究认为，氟化物涂膜的作用在于增强牙釉质的抗龋能力，氟化物涂膜涂在牙齿表面上，自然干燥后形成一层含氟薄膜，其中氟化物释放出来，对牙釉质表面起到保护作用，氟化物涂膜的使用为局部氟化物防龋又开辟了一条新途径。 本研究在国内首次进行在活体内局部氟化物涂膜后唾液氟浓度变化的研究，同时结合氟化物涂膜后牙釉质表层钙溶出量的检测，评价氟化物涂膜对牙釉质抗酸溶解性作用的效果，为实际临床应用提供科学依据。 实验材料 1．2％氟化钠涂膜和2％氟化钠溶液的配制 1．1 2％氟化钠涂膜：取8gNaF加入400ml天然树脂无水乙醇溶液中，配制成2％NaF涂膜。 1．2 2％氟化钠溶液：取8gNaF加入400ml去离子水中，配制成2％NaF溶液。 2．主要试剂 要求使用去离子水，优级纯试剂。 2．1 镧液 2．2 TISAB液 3．主要仪器 3．二 低温高速离心机：Sorvall suPer ’121，美国 DUPONT公司 3．2 氟离子选择性电极：中国长沙半导体材料厂 3．3 pH计：PHSJ C型精密酸度计，上海雷磁仪器厂 3．4 原子吸收分光光度计：AA－670，日本岛津株式会社 实验方法 1．实验对象 随机选取某中学15－17岁无龋学生20名（男10名，女10名）作为实验对象。分成实验和对照两组，每组各10人，均为男生5人，女生5人。实验组接受氟化钠涂膜处理，对照组接受氟化钠溶液处理。 2．唾液中氟浓度的测定 采集所有受试者唾液样品。于上午9点，令受试者低头让唾液自行流人 sml的试管内。将样品立即低温离心问，一4℃）30Inin，取lml上清液于一20T保存备用。按照上述方法分别采集实验组和对照组接受氟处理后1小时J小时在小时＊ 小时、24小时和36小时的唾液样品。将样品恢复至室温，加人0．10ml TI－SAB，采用标准曲线法以氟离子选择性电极测定氟浓度。 3．牙釉质表面钙溶出量的测定 采集所有受试者牙釉质表层钙溶出量样品。经三次涂氟后，分另在1上J个月采集所有受试者牙釉质表层钙溶出量样品。采用日本产AA－670原子吸收分光光度计测定钙溶出量。 4．数据处理 采用SPSS附分析软件用t检验进行显著性分析。 ·2· 实：验结果 1．实验组用氟后唾液中氛浓度与用氟前基线值比较，二小时。3小时，显著高于用氟前u＜0．01人而且用氟后1小时实验组显著高于对照组瞩＜o对门，用氟后3小时实验组高于对照组汗＜0．05）。 2．实俄用氟后牙釉质钙溶出量与用氟前基线值相比较，二个月在个月J个月，显著低于用氟前（P＜o．01人对照组用氟后3个月与用氟前相比较，无显著性差异（P＞o．05人涂氟后二个月，实验组低于对照组（P＜o．05卜2个月J个月，实验组显著低于对照组u＜o0Q。 本 论 1．氟化物涂膜和其他局部使用氟化物方法，如含氟剂漱口、氟化牙膏刷牙、含氟凝胶等相比，它能明显地延长氟化物和牙釉质表面两者的接触时间和接触浓度。Castioni等人通过对许多研究结果分析推论出：应用含有高浓度的专业氟制剂后唾液中氟水平要高于应用低浓度的氟制剂。Twetlnan等观测局部使用三种涂膜后唾液氟浓度变化情况，发现使用涂膜后升高的氛浓度持续不超过6小时，且升高的唾液氟浓度与涂膜中的含氟量相关。 本研究使用二％氟化钠涂膜后，唾液氟浓度快速升高，但是升高的氟浓度持续不超过 6 ，J’时。同 Twetman等人的报道相一致。而使用氟化钠溶液后，升高的氟浓度持续较短，不超过3小时。实验、对照两组比较，说明使用氟化钠涂膜与氟化钠溶液相比，氟化物涂膜具有快速凝固和缓慢释放氟的特性，使其在唾液中持久释放氟的浓度较高，有利于氟离子与牙釉质接触和反应。 ·3· 2．局部用氟后，在牙釉质中除了形成氟磷灰石外，还产生大量氟化钙。当口腔局部环境pH值下降时沉积于釉质表面的氟化钙物质缓慢释放出氟元素，有助于抑制牙釉质磷灰石晶体的溶解，提高抗酸脱钙能力，并能起到促进再矿化作用。氟化钙不会立即溶解消失，可持续数周、数月。大量研究表明，氟的主要通过局部作用，要获得较好的防龋效果就必须在牙齿周围的液体中有低浓度的氟持续存在。本研究采用活体牙釉质进行研究，检测钙溶出量的结果，能客观反映氟化钠涂膜对牙釉质的抗酸溶解性作用。实验组使用氟化钠涂膜后l在＊个月牙釉质表层钙溶出量随时间的增加而增高，但均明显低于用氟前K＜o．01人而对照组使用氟化钠溶液后1在J个月牙釉质表层钙溶出量虽然低于用氟前，但是3个月时钙溶出量显著增高，接近用氟前的基线值（P＞0．05人我们认为使用涂膜后沉积于釉质表面的氟化钙物质缓慢释放出氟更多还原

【Abstract】 PrefaceIn the early studies, Dean and his colleagues found the relation of fluoride and dental caries, and were sure of the caries - preventive effects of fluoride. Recently, much researchers consider that fluoride varnish can enhance the anticaries effect of dental enamel. Fluoride varnish films on the surface of dental enamel after topical application of fluoride varnish. F - ions release from the film, and then protect dental enamel. Now, topical application of fluoride varnish inaugurate new approach for the prevention of dental caries.In the present study, we i nvestigate the fluoride concentrations in whole saliva after topical application of fluoride varnish in vivo before all other researchers in China. At same time, with the analysis of the dissoved Ca from enamel after topical application of fluoride varnish , we assess effect on anti - acid solubility of fluoride varnish with dental enamel, in order to provide science foundation for clinical practice.Material1. 2% NaF varnish and 2% NaF solution2. Primary reagent2.1 Lan liquid2.2 TISAB liquid3. Primary instrument3.1 Centrifuge :Sorvall super T21, DUPONT Inc. ,USA 3. 2 Fluoride - sensitive electrode: Changsha semiconductor Inc. , China3.3 pH;PHS-3 C, Shanghai leici instrument Inc. , CHIN A3.4 Atomic absorption spectrometry: AA - 670, Shimadzu, JapanMethods1. Subjects20 caries - free students (10 Boys and 10 girls ) ranged in age from 15 to 17 years were selected and divided into NaF varnish and NaF solution groups.2. Analysis of fluoride concentration in salivaThe samples of unstimulated whole saliva were collected at baseline before a single topical application of NaF varnish or NaF solution and 1, 3, 6, 12, 24, 36h after a single topical application of NaF varnish or NaF solution. The concentration of fluoride in saliva samples was determined with a fluoride - sensitive electrode.3. Analysis of dissoved Ca from enamelThe samples of dissoved Ca from enamel were collected at before a single topical application of NaF varnish or NaF solution and 1,2,3 month after a single topical application of NaF varnish or NaF solution. The dissoved Ca from enamel was analysed with atomic absorption sectrophotometry( A A -670 Japan).4. Statistical methodsThe data were processed using the t test by SPSS7.Results1. Compared with baseline value and the values of salivary fluoride concentrations after topical application of fluoride varnish, the values after Ih, 3h were significantly higher than baseline( P <0. 01). Compared between fluoride varnish group and fluoride solution group, the values of fluoride varnish g;roup were significantly higher than fluoride solution group after lh(P<0.01); the values of fluoride varnish group were higher than fluoride solution group after 3h(P<0.05).2. Compared with baseline value and the values of dissoved Ca from enamel after topical application of fluoride varnish, the values after 1, 2, 3 months were significantly lower than baseline( P <0.01). Compared with baseline value and the values of dissoved Ca from enamel after topical application of fluoride solution, there were no significant differences between the values after 3 months and baseline ( P > 0.05 ). Compared between fluoride varnish group and fluoride solution group, the values of fluoride varnish group were lower than fluoride solution group after 1 month(P<0.05) ; were lower than fluoride solution group after 2, 3 months( P <0.01).Discussion1. According to the majority of studies, comparing with other topical fluoride products such as dentifrices or mouthrinses, fluoride varnish can prolong the time of its contact and reaction with enamel. Castioni et al. analysed the data of the concentrations of fluoride found in saliva after a single topical application have been investigated in many studies, and reasoned out that professionally applied products, containing high fluoride concentrations, lead to higher salivary levels as compared to self - applied p更多还原