含氟牙膏对固定矫治中牙釉质脱矿预防效果的研究

目的：探讨含氟牙膏在正畸固定矫治中对预防牙釉质脱矿的作用。方法本实验通过常规口腔卫生宣教指导接受固定矫治器治疗的患者分别使用不同种牙膏刷牙,将患者随机分为氟化物组和对照组,氟化物组采用含氟牙膏刷牙,对照组采用不含氟牙膏刷牙,应用时间平均18个月。分别比较矫治前后两组患者及被观察牙齿牙釉质脱矿发病率和脱矿程度,判断含氟牙膏在固定矫治中对牙釉质脱矿的预防效果。结果在正畸固定矫治中,应用氟浓度为0．15%的含氟牙膏刷牙,可明显降低牙釉质脱矿的发病率,明显减少牙釉质3度脱矿的发生。结论0．15%含氟牙膏应用于固定矫治能够降低牙釉质脱矿的程度。     

QLF法研究一种含氟涂料对离体牛牙釉质的抗酸性效果

目的：采用定量光导荧光系统观察含氟涂料对牛牙釉质的抗酸性效果。方法：20个新鲜拔除的牛前牙,于每个标本唇面建立4个2mm×2mm开窗,随机分为4组,分别用含氟涂料、含氟牙膏、1%氟化钠溶液、去离子水处理,然后浸泡在脱矿液中,分别于处理的第1,2,4,8d,采用QLF法检测各组标本的荧光损失量△F（%）和病变面积△P（mm2）,计算△Q（%,mm2）,并再次处理。结果：用含氟涂料处理的牛牙釉质龋标本,再矿化面积最多、△Q降低最大,且与其他处理组有显著差异（P〈0.05）。结论：同其它方法相比,含氟涂料有利于增进离体牛牙釉质的抗酸性。     

4种防龋方法在固定矫治中预防牙釉质脱矿的研究

目的:比较4种防龋方法在正畸固定矫治中预防牙釉质脱矿的效果.方法:采用固定矫治器矫治的200名患者随机分为4组(n=50),分别用普通牙膏、含氟牙膏、氟保护漆和护牙素对牙釉质进行处理,定期随访,比较矫治完成后4组患者的牙釉质脱矿情况.结果:按牙齿数计算含氟牙膏、普通牙膏、氟保护漆和护牙素4组牙釉质的脱矿率分别为16.3％、21.9％、9.3％和8.5％ (x2=99.7,P=0.000001)氟保护漆和护牙素组脱矿率低于其他2组,该2组脱矿率之间的差异无统计学意义(x2=0.39,P=0.529851).结论:应用含氟制剂可以有效预防固定矫治中牙釉质脱矿的发生,护牙素和氟保护漆的效果更明显.     

两种局部用氟对预防正畸牙脱矿的临床研究

目的了解固定矫治器治疗后牙齿牙釉质脱矿的发生率及严重程度，评价用75％氟化钠处理牙面和使用含氟牙膏对减轻牙釉质脱矿的作用。方法选择固定矫治器治疗的患者93例随机分为3组，氟化钠糊剂组34例，含氟牙膏组28例，对照组31例，治疗前后对牙面脱矿情况进行临床观察。结果矫治前3组患者牙齿牙釉质脱矿发生率和脱矿程度差异均无统计学意义（P〉0．05）。矫治后氟化钠糊剂组牙釉质脱矿率为8．9％，含氟牙膏组为9．0％，对照组为15．6％，两种氟处理组其脱矿率明显低于对照组，差异有统计学意义（P〈0．001）。两种氟处理组发生1度脱矿的牙数高于对照组（P〈0．05），发生3度脱矿的牙数低于对照组（P〈0．05），3组发生2度脱矿的牙数差异无统计学意义（P〉0．05）。氟化钠组和含氟牙膏组EDI小于对照组（P〈0．001），而两种氟处理组间的脱矿率和EDI差异无统计学意义（P〉0．05）。结论正畸治疗中配合使用氟化物处理牙面，可预防牙釉质脱矿的发生。     

Er, Cr: YSGG激光照射后牙体硬组织抗酸性变化的研究

目的 对Er，Cr：YSGG激光照射后牙体硬组织人工龋蚀的抗酸性变化进行体外研究，为其临床应用提供有价值的理论依据。方法 牙釉质标本采用6W，牙本质标本采用4W Er，Cr：YSGG激光照射6s，0．1mol／L乳酸脱矿，原子吸收分光光度计检测脱矿液中溶解的钙离子浓度，能谱分析仪进行原子含量分析，扫描电镜观察牙体硬组织表面结构变化。结果 Er，Cr：YSGG激光照射后牙釉质和牙本质的钙离子溶出浓度均显著低于对照组，钙含量在牙釉质和牙本质均显著高于对照组，磷含量在牙釉质和牙本质标本中都增高，但仅在牙釉质组差异有统计学意义，钙／磷重量比差异均无统计学意义。激光照射后釉质表面不平呈鳞片状，无玷污层，釉质结构清晰可见；牙本质小管开放，无熔融及碳化。结论 Er，Cr：YSGG激光照射后牙体硬组织抗酸性增强，而且激光照射不对牙体硬组织造成热损伤。     

氟以及表面活性剂对牛牙釉质脱矿的影响

本研究旨在进一步了解氟化物以及表面活性剂（SAA）对牛牙釉质脱矿的影响。在体外模拟酸蚀模型，采用自制的钙离子选择性微电极测试不同处理组的钙离子浓度，并进行分析评价。结果显示：①牙釉质经氟化钠处理后其脱矿率明显低于单用酸蚀液组（P＜0．01）；②SAA和氟化钠合用与单用氟化钠组之间无显著差异（P＞0.05）。提示氟可通过增强牙齿组织的抗酸性，降低釉质表面的溶解度而抗龋；SAA的抗龋作用有待进一步研究。     

不同浓度的四氟化物降低盐酸引起的牙釉质脱矿的体外研究

目的：研究四氟化钛（TiF4）,四氟化锆（ZrF4）,四氟化铪（HfF4）在不同浓度时对牙釉质表面脱矿的预防效果。方法：将24对离体牙（48颗,每对来自一个患者）随机分成4组,每组6对。先用不同浓度的TiF4、ZrF4、HfF4溶液局部预处理,经局部脱矿实验后,测定实验中的磷酸盐溶出量,并进行方差分析。结果：用TiF4、ZrF4、HfF4预处理以后牙釉质的磷酸盐溶出量显著减少;用ZrF4、HfF4预处理效果更好。四氟化物浓度以及预处理时间的不同对最后牙釉质磷酸盐溶出量影响不大。结论：几种四氟化物的应用能够显著减少盐酸引起的牙釉质脱矿。与TiF4相比,HfF4和ZrF4对牙釉质脱矿的预防效果更好。     

三种氟素制剂对离体乳牙牙釉质抗酸性影响的比较研究

目的 比较三种常用氟素制剂对离体乳牙牙釉质抗酸性的影响。方法 40个离体乳前牙，随机分为4组。开窗，酸蚀，1、2、3组分别涂布10%（NH4）2MoO2F4溶液，38%Ag(NH3)2F溶液，APF-LaCl3溶液联用3min,第4组涂去离子水3min，将经上述处理的牙齿标本分别浸泡于8ml0.1mol/L乳酸中，开始记时，于1、3、6、12、24、48、72、144h各取出1ml液体，检测其Ca^2 浓度的A值，计算各处理组各时间点釉4质钙溶出总量，统计分析。结果 同对照组相比，3种氟素制剂处理组牙釉质脱矿总量显著降低。其中APF-LaCl3溶液联用处理组最低，10%（NH4）2MoO2F4溶液与38%Ag(NH3)2F溶液处理组牙釉质脱矿总量无差别。结论 3种氟素制剂均可有效地抑制牙釉质脱矿。其中APF-LaCl3溶液联用作用最强，10%（NH4）2M煤F4溶液与38%Ag(NH3)2F溶液抑制牙釉质脱矿作用的能力相当。     

脉冲Nd:YAG激光照射对人牙釉质光滑面抗酸性的影响

目的：研究单独应用3种不同能量的普通脉冲Nd：YAG激光照射对光滑面牙釉质抗酸性的影响。方法：扫描电镜观察100、150、200mJ激光照射后离体人牙釉质表面的结构变化；并通过人工龋实验测量脱矿液中的釉质钙溶出量，确定单独用激光照射对牙釉质抗酸性的影响；X射线能谱仪(EDX)测量激光照射前后牙釉质中钙磷相对含量的比值的变化，初步探讨激光防龋的机制。结果：不同能量的激光照射可使表面牙釉质发生不同程度的熔化、熔融；100、150、200mJ激光照射组与末用激光照射组之间的釉质钙溶出量无明显差异(P＞0．O5)；激光照射可改变表面釉质的钙磷相对含量，100mJ组与150mJ、200mJ组相比照射前后钙磷比值的变化有显著的统计学差异(P＜0．05)。结论：不同能量的激光照射可使牙釉质表面发生不同程度的改变，但是本研究未发现单独用普通脉冲Nd：YAG激光照射有增强光滑面牙袖质抗酸性的效果。     

氟以及表面活性剂对牛牙釉质脱矿的影响

本研究旨在进一步了解氟化物以及表面活性剂（ＳＡＡ）对牛牙釉质脱矿的影响。在体外模拟酸蚀模型，采用自制的钙离子选择性微电极测试不同处理组的钙离子浓度，并进行分析评价。结果显示：①牙釉质经氟化钠处理后其脱矿率明显低于单酸蚀液组（Ｐ〈０．０１）；②ＳＡＡ和氟化钠全用与单用氟化钠组之间无显著差异（Ｐ〉０．０５）。提示氟可通过增强牙齿组织的抗酸性，降低釉质表面的溶解度而抗龋；ＳＡＡ的抗龋作用有待进一步研究。     

五种氟浓度的APF泡沫对正常釉质抗龋作用的形态学观察

为了探讨降低ＡＰＦ泡沫中氟浓度的可能性,本文研究了五种氟浓度的ＡＰＦ泡沫对牛牙正常釉质的抗龋的作用。方法实验组分别用１０００ｐｐｍ、２５００ｐｐｍ、５０００ｐｐｍ,１００００ｐｐｍ和１２３００ｐｐｍ氟浓度的ＡＰＦ泡沫处理正常牛切牙釉面后,放酸胶中,做人工龋试验,比较其病变深度和脱矿程度上的差别。     

猕猴舌下——舌神经移位移植的病理学研究

目的 通过猴桃舌下－舌神经移位移植后的病理改变,证实舌神经移位移植后运动神经可以再生,舌肌可以重建其动力功能的临床应用价值。方法 采用ＨＥ常规染色,嗜银,髓鞘特殊染色及免疫酶标记、透射电镜,观察不同时期神经移位移植后舌肌的组织反应及神经重建状况,测定肌纤维中羟脯氨酸的含量。结果 神经移植３月、６月、１２占膜未见萎缩,舌肌间肌纤维萎缩以舌前份较为明显,Ｓ－１００蛋白染色显示肌束及肌纤维间可见神经纤维     

Fluoride uptake and development of artificial erosions in bleached and fluoridated enamel in vitro

The aim of the present in vitro study was to evaluate the effect of carbamide peroxide (CP) bleaching on fluoride uptake in enamel. Additionally, the susceptibility for erosion in bleached and fluoridated enamel was tested. Each four enamel specimens were prepared from 44 bovine incisors. The four samples gained from each tooth were distributed among four groups (A-D) of 44 specimens each: A: (unbleached/unfluoridated) served for determination of baseline fluoride concentration; B: (unbleached/fluoridated) four times in 2000 ppm NaF solution (2 min); C: (bleached/unfluoridated) four times in 10% CP (8 h); D: (bleached/fluoridated) four times in 10% CP and fluoridation. In 22 specimens of each group both KOH-soluble and structurally bound fluoride were determined in the outermost 30 micro m of the enamel. In the remaining specimens erosions were induced by immersing the samples in 5 mL of 1% citric acid (20 min) and microhardness was evaluated before and after demineralization. Statistical analysis showed that KOH-soluble fluoride uptake was similar for group B and D specimens. Structurally bound fluoride uptake after fluoride application in unbleached samples was significantly higher than in bleached ones. Bleaching only resulted in a highly significant fluoride loss. In all samples erosion caused a significant microhardness loss. The study showed that pre-treatment of enamel with CP followed by fluoridation does not improve erosive resistance. Moreover the study reveals that CP treatment decreases concentration of structurally bound fluoride in enamel which could not be outweighed by fluoridation with 2000 ppm NaF. It is concluded that it is not feasible to improve fluoride uptake in enamel with a pre-treatment with 10% CP.     

Effects of two fluoride gels on fluoride uptake and phosphorus loss during artificial caries formation

Blocks of human enamel were cycled through a demineralization--F-treatment-remineralization procedure and then analyzed for fluoride and the presence of caries-like lesions. Treatments with a sodium fluoride gel (5000 ppm F) increased the enamel fluoride concentration to 6500 ppm F, whereas a stannous fluoride gel (1000 ppm F) increased enamel fluoride to about 1200 ppm F. Although a control treatment (water) allowed caries-like lesions to form, as observed by microradiography, no lesions were found in either of the fluoride-treated groups. When the experiment was repeated with radioactive teeth, mineral loss, as determined by release of 32P, was again greatest in the water-treated control group, but some loss was observed in the fluoride treatment groups. The least loss was found in the sodium fluoride group. It was concluded that the fluoride treatments not only increased enamel resistance but also enhanced remineralization so that calcium phosphate was replaced during the subsequent remineralization phase. Because of the probability that stannous ions were deposited during the stannous fluoride treatments, some of the apparent calcium phosphate re-deposition in this group was probably stannous compounds.     

含氟牙膏对釉质脱矿影响的体外研究

目的：探讨国内常见市售含氟牙膏对完整釉质及脱矿釉质的作用。方法：测定市售的3种含氟牙膏的氟含量,并选取釉质完好的牛牙及人工龋脱矿的牛牙,用3种含氟牙膏和不含氟牙膏刷洗釉面后,乳酸处理1min,用原子吸收光谱仪测定溶出的钙量。结果：含氟牙膏组和不含氟牙膏组均能使完整奥质的溶钙量明显降低,与空白对照组相比差异有显著性;含氟牙膏组和不含氟牙膏组均能使人工龋脱矿釉质的溶钙量明显下降,并且两组间有显著性差异。结论：含氟牙膏可以增强完整釉质及人工龋脱矿釉质的抗酸溶钙能力,且效果与其氟浓度相关,氟浓度为52.63umol/L时可显著提高牙齿抗酸力。     

Fluoride varnishes and caries development in primary tooth enamel: an in vitro study

This in vitro study evaluated the effect of fluoride varnishes on caries development in primary tooth enamel using polarized light microscopic techniques. A total of forty extracted or exfoliated primary teeth with intact, caries-free smooth surfaces underwent a fluoride-free prophylaxis and soft tissue were assigned to one of the following groups: 1) duraphat (5 percent sodium fluoride, vanish, Colgate, n=10); 2) Duraflor (5 percent sodium fluoride, Pharmascience, n = 10); 3 Cavity Shield (5 percent sodium fluoride varnish, Omni, n=10); and 4) Control (n=10). An acid-resistant coating was applied to the specimens leaving an exposed window of sound enamel (5mm x 1mm). The fluoride varnishes were applied to the primary teeth according to the manufacturer's recommendation. Following thermocycling (500 cycles, 5-50 degrees C) of the fluoride varnish-treated and control teeth, a fluoride-free pumice toothbrushing was performed to remove visible and macroscopically (dissecting microscope at 16x) detectable fluoride varnish. An acid resistant coating was reapplied where necessary, leaving the fluoride varnish treated sound enamel window exposed. Following in vitro caries formation (2.2mM Ca, 2.2mM PO4 50mM acetic acid, 0.5ppm fluoride, pH 3.90), longitudinal sections (5 per specimen) were obtained and evaluated by polarized light microscopy for mean lesion depth. Comparisons were made among treatment and control groups.     

Remineralization and acid resistance of enamel lesions after chewing gum containing fluoride extracted from green tea

Background: The aim of this study was to evaluate enamel remineralization and the acquisition of acid resistance by using sugar‐free chewing gum containing fluoride extracted from green tea. Methods: Forty‐five volunteers participated in a crossover, double‐blind study and wore intraoral appliances with human demineralized enamel. Subjects chewed fluoride chewing gum (FCG: 50 μg fluoride) or placebo gum. Remineralization and acid resistance were evaluated using the mineral change value (ΔZ, in vol%·μm). Fluoride concentrations in saliva and remineralized enamel were analysed. Results: The peak salivary fluoride concentration was 3.93 ± 1.28 ppm (mean ± SD). The elevated salivary fluoride concentration resulted in a higher fluoride concentration of 656 ± 95 ppm in the remineralized region versus 159 ± 26 ppm for placebo gum (p < 0.001). After remineralization, the ΔZ of the FCG group was higher than that of the placebo gum group. After an acid challenge, ΔZ of the FCG group was lower than the placebo gum group. Both ΔZ were statistically significant. Conclusions: FCG produced a superior level of remineralization and acid resistance, as compared to the placebo gum. The in situ results suggest that regular use of FCG is useful for preventing dental caries.     

Effect of fluoride on caries progression and dentin apposition in rats fed on a cariogenic or non-cariogenic diet

The effect of fluoride in drinking water on the progression of dentinal caries and dentin apposition was studied in Wistar rats. The initiation of enamel caries lesions was first induced for 2 wk with S. sobrinus and a 43% sucrose diet after weaning. Thereafter the animals were fed on either a cariogenic or a non-cariogenic diet and distilled water supplemented with 0, 1, 7 or 19 ppm fluoride. The areas of dentinal caries and dentin apposition were quantified after tetracycline staining. Fluoride reduced dentinal caries progression after the initiation of lesions in the presence of a cariogenic diet at a concentration of 19 ppm F, and without sucrose at 1 ppm F. The effect of fluoride in reducing dentin apposition with a cariogenic diet was dose-dependent, whereas fluoride in non-cariogenic groups had practically no effect on dentin formation. These results suggest that fluoride together with a high concentration of sucrose in the diet might have an odontoblast-mediated effect on the regulation of the progression of dentinal caries.     

Incorporation into human enamel of fluoride slowly released from a sealant in vivo

Fluoride incorporation into human enamel from an experimental sealant resin in vivo was investigated. The sealant consisted of a newly synthesized methacryloyl fluoride-methyl methacrylate (MF-MMA) copolymer resin, which contains acidic fluoride covalently bonded to carbonyl groups and releases fluoride ions slowly by hydrolysis in an aqueous environment. This experimental sealant was applied to the enamel of permanent pre-molars and the control sealant without MF-MMA copolymer to that of the contralateral teeth. Fluoride concentration was determined by an enamel biopsy procedure with acid-etching four weeks after the sealant application. As much as 3500 ppm fluoride was found to be deposited at 10 microns depth in the enamel under the MF-MMA copolymer sealant. The increase in fluoride concentration was significant even at 60 microns. Of the fluoride incorporated into the enamel, from 70 to 80% was present as a tightly bound form. This resin sealant is expected to protect the enamel from caries attack even after detachment of the sealant.     

氟化物与镧、钼协同应用抑制牙釉质脱矿过程的研究

目的 :明确氟化物与镧、钼协同应用的防龋效果 ,为其应用研究提供实验依据。方法 :体外建立人工龋模型 ,氟离子、镧离子、钼离子分别应用及协同应用预处理后形成的人工龋 ,经扫描电镜和显微硬度测量研究表明 ,氟与钼、镧协同应用预处理形成的牙釉质人工龋 ,其脱矿深度较用同样浓度单独含镧、钼或氟预处理液处理者浅 ,釉质脱矿最轻 ,形成的人工龋深度最浅。釉质表面形成的覆盖物最厚、致密 ,呈块状和片状结晶 ,晶粒大、与下方釉质结合紧密。显微硬度高 ,它在抗酸实验中显示了较强的抗酸性。协同应用的防龋机理亦被探讨。结论 :氟、钼、镧协同应用防龋效果最好