五倍子水提取物处理早期人工釉质龋后表面结构的扫描电镜观察

目的观察五倍子水提取物处理早期人工釉质龋后的表面形态。方法采用化学人工龋制备法,将釉质块随机分成六组,分别用1、10、30mg/mL五倍子溶液,380mL/L氟化氨银,20mL/L氟化钠以及去离子水处理,进行体外pH循环,扫描电镜观察釉质表面结构。结果经五倍子与氟化氨银处理后的釉质表面形成致密均匀、形状不规则的指状结构,长约0.08~0.6μm;氟化钠处理后釉质表面形成大小不一,散在的小球状结构,直径约0.02~2μm;去离子水处理的釉质表面成蜂巢状结构。结论1、10、30mg/mL五倍子溶液处理后釉质表面结构与氟化氨银组相似;1mg/mL可能是五倍子水提取物的有效浓度,但不一定是最低有效浓度;从表面形态上看,五倍子所生成的结构可能与抑制脱矿、促进再矿化有关。     

不同浓度五倍子水提取物抑制釉质脱矿效果的研究

目的:探讨五倍子水提取物抑制釉质脱矿的最佳浓度.方法:以Sigma公司五倍子鞣酸作为标准品,用比色法对五倍子水提取物中的鞣酸含量进行定量测定.分别用4、8、16、30、60、120 ms/mL的五倍子水提取物液对釉质表面进行处理,采用人工脱矿液脱矿.显微放射照相技术分析,比较其脱矿量和脱矿深度.自动电位滴定仪测定各组脱矿液中的Ca2+浓度.结果:五倍子水提取物中的鞣酸含量为81.3%;当浓度达到30 mg/mL以上时,五倍子抑制釉质脱矿效果显著,且各实验组之间各项差异很小,不具有统计学意义.结论:当五倍子水提物中的鞣酸含量为80%左右时,其抑制釉质脱矿的最佳浓度为30 ms/mL.     

五倍子对釉质抗酸蚀作用的实验研究

目的：观察中药五倍子对釉质抗酸蚀作用的效果。方法：采用500g/L五倍子水浸剂为实验组，去离子水为阴性对照，20g／L氟化钠为阳性对照，对60个正常离体牙釉质表面进行处理，制备人工龋模型，用硬组织切片机制备100μm原切片，通过显微放射照射系统观察测量五倍子对釉质的抗酸蚀作用效果。结果：500g／L五倍子水浸剂组较去离子水对照组脱矿少（P〈0．05），与20g／L氟化钠对照组相比无显著差异（P〉0．05）。结论：500g／L五倍子水浸剂可明显增强釉质抗酸蚀能力，其效果与20g／L氟化钠相当。     

五倍子提取液促进实验性根面龋再矿化的研究

目的：研究五倍子提取液促进实验性根面龋再矿化的作用。方法：采用化学法制备根面龋模型，用500g／L五倍子提取液，380g／L氟化氨银液，20g／L氟化钠液和去离子水处理后放人再矿化液中7d，用扫描电镜和显微放射成像术分别观测其表面形态、龋损深度和脱矿量。结果：再矿化前，扫描电镜观察五倍子与氟化氨银处理后牙骨质龋表面形成不规则短钝状突起；氟化钠液组形成大小不一的散在大球状突起，可见一些腔隙存在；去离子水组大量分布夏伯氏纤维。再矿化后，五倍子液和氟化氨银液组表面结构更加致密，均匀，呈小斑块，条索状；氟化钠液组表面也出现条索状结构，但仍有孔隙或腔隙存在；去离子水组表面出现蜂窝状结构。显微放射成像术分析各药物处理组均能明显促进实验性根面龋的再矿化，与去离子水相比相差显著（P〈0．05），其中氟化氨银液组效果最好，五倍子液和氟化钠液相当。结论：五倍子具有抑制实验性根面龋进展，促进其再矿化的作用。     

天然药物五倍子与氟化钠对釉质脱矿的影响比较研究

目的：比较天然药物五倍子和化学制剂氟化钠对釉质脱矿的影响，为天然防龋药物的开发提供理论依据。方法：利用连续培养系统建立牙齿龋病模型，经五倍子和氯化钠处理后，利用偏光显微镜和扫描电镜观察比较二者对牛牙釉质龋形成的影响。结果：偏光显微镜和扫描电镜观察发现：五倍子和氟化钠都能抑制釉质早期龋的形成，表现为釉质表面的破坏程度较轻，釉质表层连续完整，并在表层脱矿区观察到有再矿化区域的存在。但本实验浓度下五倍子的功效弱于氟化钠。结论：在龋病模型中，本实验浓度的五倍子能够有效抑制釉质早期龋的形成，提示五倍子是一种具有防龋效果的天然药物。     

微量元素矿化液促进釉质龋再矿化层形成机理的研究

目的：观察不同成份的再矿化液对人工釉质龋表层下脱矿的再矿化作用和再矿化层的形成机理。方法：选择牛牙３６颗于乳酸凝胶中形成人工釉质龋、两周后将以上脱矿釉质块随机分成４组样本,其中３组为实验组,１例为对照组。实验组釉质块分别置无氟、含氟及含有氟、钙、磷、锡等微量元素的再矿化液中;对照组用去离子水代替再矿化液。借助Ｘ光电子能谱、扫描电镜、偏光显微镜等,观察不同的矿化液处理人工釉质龋后脱矿釉质表面沉积物的     

预防与保健

北京市西城区学生家长口腔健康知膜识、观念及行为调查；高龄人群口腔卫生保健情况调查；氟保护漆治疗老年人根龋的疗效观察；牙科治疗中不合作儿童的气质研究；2种光固化窝沟封闭剂的防龋效果评价；五倍子水提取物对正常釉质及去有机质釉质脱矿影响的实验研究；不同饮料对离体乳牙釉质的脱矿作用。[编者按]     

五倍子提取液对实验性根面龋再脱矿作用的影响

目的：探讨中药五倍子提取液对实验性根面龋的抑制作用。方法：以50％五倍子提取液为实验药物,38％氟化双氨银[Ag（NH3）2F],2％氟化钠（NaF）为阳性对照,去离子水为阴性对照。测量实验性根面龋再脱矿中脱矿量与时间的关系及总矿物质损失量。结果：38％Ag（NH3）2F抑制脱矿作用最强,其余依次为50％五倍子提取液、2％氟化钠、去离子水。50％五倍子提取液与38％Ag（NH3）2F、2％氟化钠无显著性差异（P〉0．05）,各药物处理组与去离子水比较均有显著性差异（P〈0．01）。结论：50％五倍子提取液对Ca^2＋溶出量及总矿物质损失量具有显著的抑制作用,对Ca^2＋溶出量的抑制作用优于2％NaF。     

特异性鸡蛋黄抗体对人工釉质龋形成的影响

目的：研究特异性鸡蛋黄抗体（IgY）对人工釉质龋形成的影响。方法：采用人工菌斑模型研究IgY对早期釉质龋形成的影响。56块釉质块经唾液包被后置6种与菌斑形成有关的混合细菌液中培养。实验组釉质块每两天置IgY液中浸泡处理,在实验第7、14、21、28、35天分别取出对照、实验组釉质块,磨片后偏光显微镜下观察,并采用显微X线照相系统投照,TMR软件分析早期釉质脱矿量、龋损的深度。结果：对照组较实验组更早出现釉质龋,实验组釉质脱矿量为1275．2 vol％um,显著低于对照组2836．5vol％ um。结论：特异性IgY在体外能有效减缓早期釉质龋的发生。     

天然药物隔山消促进釉质再矿化的研究

目的:观察隔山消水提取物处理早期人工龋后的表面形态。方法:采用化学方法建立牙齿龋病模型,分别经五倍子和隔山消处理后,利用扫描电镜观察二者对牛牙釉质龋再矿化的影响。结果:经隔山消处理后的釉质块表面有较紧密均匀的结晶区,五倍子有规则均匀的矿物沉淀,去离子水处理的釉质表面呈蜂窝状结构。结论:在龋病发生过程中隔山消可能对龋病的进展具有抑制作用,五倍子的再矿化作用强于隔山消。     

五倍子提取液对牙本质龋损时胶原蛋白分解的影响

目的：评价五倍子提取液在牙本质龋损中对胶原分解的影响。方法；乳酸胶体系统致牙本质龋，20ml/L氟化钠，五倍子提取液，380ml/L氟化双氨银，去离子水4组试剂分别处理，再次脱矿及I型胶原酶牙本质基质，氯胺－T法对各组胶原分解量进行分析。结果：五倍子组和380ml／L氟化双氨银组对I型胶原酶分解胶原均有显著抑制作用（P＜0．01），且五倍子组明显优于380ml/L氟化双氨银组的抑制胶原分解作用（P＜0．01），结论：五倍子能抑制胶原分解，对脱矿的进一步进行产生影响，从而使牙本质龋的进展受到抑制。     

氟化微量元素制剂对牙釉质显微硬度变化影响的实验研究

目的：比较氟化微量元素制剂对酸蚀下牙釉质显微硬度降低的抑制作用,为找到低毒高效的防龋制剂提供依据。方法：牙釉质样本分别经含相同氟浓度的5种氟化微量元素制剂（氟化锌、氟化镧、氟化亚锡、氟化锶、氟钼酸铵）及氟化钠处理后酸蚀,MH-5型显微硬度计测量牙釉质酸蚀前后显微硬度,观察牙釉质显微硬度的变化。结果：氟化钠、氟化锌、氟化锶、氟化亚锡、氟化镧、氟钼酸铵均有抑制酸蚀下釉质显微硬度降低的作用,其中氟化亚锡对酸蚀下牙釉质显微硬度降低的抑制作用明显强于氟化钠（P〈0．05）。结论：含锡氟化物可显著提高牙釉质的抗酸能力,在抑龋防龋方面,氟化微量元素拥有广泛的应用前景。     

五倍子抑龋作用的实验研究

目的 :观察中药五倍子对釉质龋形成、发展的影响。方法 :采用多种致龋菌体外培养形成类似于口内的多菌种致龋菌斑 ,与釉质块共同孵育 ,形成釉质龋。测量龋损深度及脱矿液内的Ca、P含量 ,用扫描电镜观察釉质龋表面形态。结果 :五倍子对龋发生过程中的脱Ca具有抑制作用 ,与去离子水组比较具有显著性差异 (P <0 .0 1) ,但作用小于 2 0ml/LNaF(P <0 .0 5 )。对龋损深度的影响与去离子水组有显著性差异 ,与2 0ml/LNaF组无显著性差异。结论 :在龋发生过程中五倍子可能对龋病的进展具有抑制作用。     

Effects of low-energy CO2 laser irradiation and the organic matrix on inhibition of enamel demineralization

In the past two decades, accumulated evidence has clearly demonstrated the inhibitory effects of laser irradiation on enamel demineralization, but the exact mechanisms of these effects remain unclear. The purpose of this study was to investigate the effects of low-energy CO2 laser irradiation on demineralization of both normal human enamel and human enamel with its organic matrix removed. Twenty-four human molars were collected, cleaned, and cut into two halves. One half of each tooth was randomly selected and its lipid and protein content extracted. The other half of each tooth was used as the matched control. Each tooth half had two window areas. All the left windows were treated with a low-energy laser irradiation, whereas the right windows served as the non-laser controls. After caries-like lesion formation in a pH-cycling environment, microradiographs of tooth sections were taken for quantification of demineralization. The mean mineral losses (with standard deviation) of the enamel control, the lased enamel, the non-organic enamel control, and the lased non-organic enamel subgroups were 3955 (1191), 52(49), 4565(1311), and 1191 (940), respectively. A factorial ANOVA showed significant effects of laser irradiation (p = 0.0001), organic matrix (p = 0.0125), and the laser-organic matrix interaction (p = 0.0377). The laser irradiation resulted in a greater than 98% reduction in mineral loss, but the laser effect dropped to about 70% when the organic matrix in the enamel was removed. The results suggest that clinically applicable CO2 laser irradiation may cause an almost complete inhibition of enamel demineralization.     

氟化微量元素制剂对牙釉质脱钙影响的实验研究

目的：比较氟化微量元素制剂对酸蚀下牙釉质脱钙的抑制作用,为找到低毒高效的防龋制剂提供依据。方法：牙釉质样本分别经含相同氟浓度的5种氟化微量元素制剂（氟化锌、氟化镧、氟化亚锡、氟化锶、氟钼酸铵）及氟化钠处理后酸蚀,甲基麝香草酚蓝法检测酸蚀液中钙浓度的变化。结果：氟化钠及氟化微量元素均有抑制酸蚀下釉质脱钙的作用（p〈0．05）;其中氟化亚锡作用最为明显,与氟化钠等比较有显著性差异（p〈0．01）。结论：锡可明显提高氟化物的防龋生物活性,在抑龋防龋方面,氟化微量元素有广泛的应用前景。     

Effect of 0.02% NaF solution on enamel demineralization and fluoride uptake by deciduous teeth in vitro

The application of 0.02% NaF solution on teeth with a cotton swab instead of brushing with fluoride dentifrice has been suggested for young children to reduce the risk of dental fluorosis, but its anticariogenic effect has not been evaluated. Thus, we studied the in vitro effect of 0.02% NaF solution on enamel demineralization and fluoride uptake in deciduous teeth; non-fluoride dentifrice and fluoride dentifrice (1.100 mug F/g) were used, respectively, as negative and positive controls. The treatment with fluoride dentifrice was more effective in reducing enamel demineralization (p < 0.05) and on fluoride uptake by the enamel (p < 0.05) than the non-fluoride dentifrice and the 0.02% NaF solution. Data suggest that the alternative use of 0.02% NaF solution instead of fluoride dentifrice should be reevaluated especially if dental caries are to be controlled.     

Effect of fluoridated milk on enamel and root dentin demineralization evaluated by a biofilm caries model

Although some studies suggest an anticaries effect of fluoridated bovine milk (F-milk) on enamel, evidence is still considered weak. Even more uncertain, the effect of F-milk on root caries remains largely unknown. This study evaluated the effect of F-milk on enamel and on root dentin demineralization using a validated Streptococcus mutans biofilm model, simulating a high cariogenic challenge. S. mutans (UA159) biofilms were formed on bovine enamel and root dentin saliva-coated slabs after measuring initial surface microhardness (SH). Biofilms were exposed to 10% sucrose 8×/day and treated 2×/day with either: (1) 0.9% NaCl (negative control), (2) bovine milk, (3) F-milk (5.0 ppm F as NaF) or (4) NaF 0.05% (anticaries-positive control). Medium pH was monitored twice/day, as a biofilm acidogenicity indicator. After 5 days for enamel and 4 days for dentin, biofilms were recovered to analyze: biomass, soluble proteins, viable microorganisms, and extra- and intracellular polysaccharides. Enamel and dentin demineralization were estimated by percentage of SH loss. Results were compared by ANOVA and Tukey's test. Neither acidogenicity nor biofilm composition differed among treatment groups in biofilms formed on enamel or dentin (p > 0.05). F-milk, however, significantly reduced enamel and dentin demineralization when compared with the negative control (p < 0.05). Also, F-milk was as efficient as 0.05% NaF to reduce enamel (p > 0.05), but not dentin demineralization (p < 0.05). These findings suggest that milk containing 5.0 ppm of fluoride is effective to control enamel caries and that it may be effective on root dentin caries prevention.     

Laser-matrix-fluoride effects on enamel demineralization

Laser and fluoride have been shown to inhibit enamel demineralization. However, the role of organic matrix and their interactions remains unclear. This study investigated the interaction among CO2 laser irradiation, fluoride, and the organic matrix on the demineralization of human enamel. Twenty-four molars were selected and cut into halves. One half of each tooth was depleted of its lipid and protein. The other half served as a matched control. Each tooth half had two window areas, treated with a 2.0% NaF gel. All left windows then received a laser treatment. Next, the tooth halves were subjected to a four-day pH-cycling procedure that created caries-like lesions. Tooth sections were cut from the windows, and microradiographs were used for quantification of the demineralization. The combined fluoride-laser treatment led to 98.3% and 95.1% reductions in mineral loss for enamel with and without organic matrix, respectively, when compared with sound enamel.     

Effect of xylitol:sorbitol on fluoride enamel demineralization reduction in situ

OBJECTIVES: To evaluate if sugar alcohols would reduce enamel demineralization enhancing the fluoride (F) effect. METHODS: A crossover in situ study was conducted in four phases, during which 10 volunteers were submitted to one of the treatments: (I) Distilled and deionized water, as a negative control; (II) F (226 microg F/ml as NaF; concentration used in commercial mouthrinse); (III) X:S (xylitol:sorbitol 1:3; final concentration 1.6M; 28% of sugar alcohols) and (IV) F+X:S (same final concentration that groups II and III). The volunteers wore palatal appliances containing four bovine enamel blocks of known surface microhardness (SMH), covered with a 'test plaque' of mutans streptococci, which were immersed during 1 min in one of the allocated treatment solutions simultaneously that the volunteers rinsed their mouths with the same solution. After the rinsing the appliances were put in the mouth and after 20 min a cariogenic challenge was made with 20% sucrose solution during 1 min. After further 45 min the 'test plaque' was collected for F analysis, enamel SMH was again determined and the percentage of change in relation to baseline was calculated; F uptake in enamel was also determined. RESULTS: With respect to all the analyses made, the group F+X:S did not differ from the F treatment (p>0.05) and the groups treated with F and F+X:S differed from the negative control (p<0.05). CONCLUSIONS: The results suggest that xylitol:sorbitol may not enhance the effect of fluoride present in mouth rinse on the reduction of enamel demineralization.