成膜基质对氟化物涂膜提高釉质抗脱矿性能的影响

目的:评价成膜基质材料对氟化物涂膜提高釉质体外抗脱矿性能的影响。方法:在制备的5组牛牙釉质试样表面分别涂布以5种成膜基质(渗透型丙烯酸树脂、珂巴树脂、聚合松香、聚乙烯醇缩丁醛、甲基丙烯酸共聚树脂)配制的5种氟涂膜材料,另有一组不做处理,为对照组。在保湿12 h后,除去涂膜,然后对所有试样进行脱矿-再矿化循环处理7 d,之后纵向剖切试样,测定纵剖面显微硬度(HK),并用扫描电镜观察釉质处理面。结果:在釉质表面下90μm深度范围内的相同深度,所有涂膜组釉质的显微硬度均明显高于对照组(P<0.05);在釉质表面下50μm深度范围内的相同深度,渗透型丙烯酸树脂组的釉质硬度大于其它4组(P<0.05);各组釉质表面在扫描电镜下呈现不同特点的脱矿形式。结论:成膜基质材料对氟化物涂膜提高釉质体外抗脱矿性能有明显影响,含渗透型丙烯酸树脂的氟涂膜对抗釉质脱矿效果更佳。     

镧、钙、氟对釉质脱矿影响的比较

目的：用化学致龋法对比镧、钙、氟对釉质脱矿的影响。方法：１５０个离体前磨牙分成６组,用酸性凝胶化学致龋,偏光显微镜观察龋形态及深度。结果：各实验组龋深度均浅于对照组,镧处理组龋深度浅于钙、氟及镧氟、氟镧先后处理组。结论：推测镧可从改善釉质结构及增加釉质外环境中钙饱和度两方面增强釉质的抗酸能力。     

正畸粘接用玻璃离子粘固剂防治托槽周围釉质脱矿的体外pH循环实验

目的　通过体外pH循环实验研究树脂改良型玻璃离子粘固剂 (resin modifiedglassionomercement)对托槽周围釉质脱矿的抑制作用。方法　选择 5对离体前磨牙 ,实验组用树脂改良型玻璃离子粘固剂粘接托槽 ,对照组用复合树脂粘接剂粘接托槽。全部样本每天进行pH循环实验 ,共60d。用偏振光显微镜观察托槽周围釉质脱矿病损并测量病损体部的深度、面积以及病损边缘与粘接材料边缘的距离。结果　对照组托槽周围釉质脱矿病损的深度和面积均大于实验组 ,配对t检验表明 2组间差异有非常显著性 (P <0 0 0 1 )。实验组病损均远离玻璃离子粘固剂边缘 ,而对照组病损均深入复合树脂粘接剂边缘的下方。结论　树脂改良型玻璃离子粘固剂是一种可以减少正畸治疗中釉质脱矿的粘接材料     

精氨酸牙膏对釉质早期龋再矿化作用的研究

目的 研究精氨酸牙膏对人牙釉质早期龋的再矿化效果。方法 制备人牙釉质龋标本,随机分为 3组：空白组（去离子水处理）,对照组（普通市售含氟牙膏处理,含质量分数 0.14%单氟磷酸钠）,实验组（精氨酸牙膏处理,含质量分数 0.14%单氟磷酸钠和 8%精氨酸）。经体外 pH循环 10 d,测量 pH循环前后各组样本的表面显微硬度,计算其差值;并通过偏光显微镜观察各组样本再矿化前后的形态学改变。pH循环结束后,脱矿处理 2h,测量其表面显微硬度,计算与 pH循环前的差值,评估再矿化处理对釉质抗酸能力的影响。采用酸蚀法测定各组的氟摄入量。结果 与对照组和空白组比较,实验组釉质表面的显微硬度、抗酸能力,以及氟摄入量均明显升高。偏光显微镜下观察,实验组病损深度明显变浅,且有表层下再矿化条带,而空白组与对照组病损无明显变化。结论 精氨酸牙膏能有效促进人牙釉质龋表层及表层下再矿化,在早期龋的防治领域具有较大的临床应用前景。     

两种氟防龋涂膜材料的释氟性及抗脱矿能力的研究

目的 比较两种氟防龋涂膜材料的释氟性及其提高釉质的抗脱矿能力。方法 将两种市售的FQ氟涂膜和多乐氟涂膜分别涂覆于20 mm×20 mm的方形聚酯塑料载片表面，每个聚酯塑料载片浸于20mL去离子水中，分别于浸水后3 h、6 h、12 h及24 h测定氟离子浓度，计算释氟率；扫描电镜观察氟涂膜表面形貌。制备5 mm×5 mm×3 mm的牛切牙釉质块，自凝树脂包埋后表面打磨抛光，测定初始表面显微硬度(SMH0)，在釉质块表面涂覆氟涂膜，浸水12 h，然后去除氟涂膜，对釉质块进行pH循环脱矿，7天后测定釉质块表面显微硬度(SMH1)，计算脱矿后釉质表面显微硬度下降率，设立阳性对照和阴性对照。结果 FQ氟涂膜和多乐氟3 h、6 h、12 h、24 h释氟率分别为(2.73±0.27)%、(3.19±0.05)%、(3.58±0.19)%、(3.63±0.08)%和(0.16±0.02)%、(0.34±0.03)%、(0.43±0.03)%、(0.48±0.03)%；经过pH循环脱矿后，应用过氟涂膜的釉质表面显微硬度下降率显著低于未用氟涂膜的釉质（85.95±3.50）%,FQ氟涂膜和多乐氟的硬度...     

缓释氟粘贴片对釉质病变深层脱矿的再矿化及沉积物的分析

目的研究缓释氟粘贴片对釉质病变深层脱矿的再矿化作用及沉积物成分分析.方法12个牛牙釉质块,根据其48小时人工龋的表面硬度值均衡分为两组,在体外滴定系统中分别用0.25mgF和0.5mgF的氟粘贴片处理,4小时/片,共22片.11片和22片处理后,分别测定每组一个标本的剖面硬度值和其余标本的表面硬度值;用偏光显微镜和显微X线观察组织学变化;用扫描电镜观察标本表面和剖面的沉积物,用能谱进行元素分析.结果使用氟片越多,标本的表面硬度值越高(P＜0.001);但等片数处理后,两剂量组标本的表面硬度值(P＞0.05)及剖面硬度值间无显著差异.偏光和显微X线检查发现22片0.25mgF氟粘贴片处理后釉质病变区矿物增加最多、效果最好.沉积物多为圆形或近圆形颗粒,少数呈圆柱状,主要成分为钙和磷,釉表面比釉深层氟含量稍高.结论在本实验条件下,氟粘贴片对釉质病变深层脱矿有再矿化作用,22片0.25mgF氟粘贴片处理后效果较好.釉质表面及内部沉积物为钙磷酸盐类,表面可能有CaF2.     

加氟的人工唾液对乳牙釉质矿化的影响

关于氟化物对釉质的局部作用多研究氟素对齿质的直接作用。目前,儿童牙科临床使用氟化物主要是牙面涂擦法,而很少研究唾液和氟素的作用来控制龋蚀。作者采用微射线照相术、偏光显微镜法、元素分析法、电子显微镜法,以及钙、磷、氟的沉积量的定量等方法,对氟素浓度的釉质矿化影响进行了观察:1.通过酸处理,使乳牙釉质脱矿,酸处理后再浸泡在人工唾液中。在脱矿部的釉质内部和表面产生不同的     

氟化物涂膜对正畸固定矫治中牙釉质脱矿影响的SEM研究

目的：采用扫描电镜（SEM）观察氟化物涂膜对抑制离体牙牙釉质脱矿及促进再矿化的功效。方法：选择因正畸需要拔除的前磨牙15颗,经37％磷酸处理,制备人工釉质脱矿标本,并用氟化物涂膜进行表面处理。采用SEM对标本脱矿前（对照组）,脱矿后（脱矿组）以及氟化物涂膜治疗后（治疗组）的表面形貌进行观察分析。结果：对照组与脱矿组之间、脱矿组与治疗组之间形态学存在显著差异,而对照组与治疗组之间形态学差异相对较小。结论：氟化物涂膜可有效改善釉质脱矿后的牙齿脱矿形貌。     

饮料导致釉质组织和形态学改变的观察

目的 :观察不同种类饮料对釉质组织和形态学的改变。方法 :采用体视显微镜、偏光显微镜和扫描电镜观察不同种类饮料浸泡釉质后 ,釉质表面超微结构和组织学的改变 ,饮料的处理是 3 7℃ ,每天 10次 ,每次 5min。设去离子水为对照组。结果 :体视显微镜观察表明 ,除矿泉水外 ,其余饮料导致釉质表面不同程度组织缺失 ,有色饮料能导致釉质表面颜色的改变且随处理时间的延长而加深。偏光显微镜观察表明磨片浸喹啉后脱矿区呈负性双折射 ,而浸水时则呈正性双折射。扫描电镜也观察到釉柱出现不同程度的脱矿 ,可乐和橙汁的脱矿作用较钙奶强。矿泉水和去离子水处理的釉质未见脱矿征象。结论 :实验饮料除矿泉水外均能导致釉质脱矿     

流速、pH 值及血浆氟化物浓度对人腮腺唾液氟浓度影响

体外研究显示釉质周围氟浓度微小变化,都影响釉质脱矿与再矿化。唾液氟是菌斑及釉质氟来源之一。本研究目的之一是在摄取1mg 氟化物后血浆氟浓度和腮隙液流速的改变对氟通过腮腺排泄的影响;其二是摄取5mg 氟化物后腮腺流速和 pH 对腮腺液与血浆氟浓度比值的影响。实验收取口服氟化物后一定时间间隙时不同唾液流速下唾液与血标本,测其氟浓度。发现:血浆氟化物     

Caries inhibiting effect of ammonium fluoride varnish in vitro

The reaction of incorporation of fluoride into tooth enamel from NH4F varnish, and Duaphat were measured using SEMq2 in vitro. Level of enamel uptake of fluoride was highest in teeth treated with NH4F varnish. Average depth of fluoride penetrated into enamel was more than 80 microns from the two varnishes. Prolonged coating duration from 24 hours to 1 week did not increase uptake and penetration of fluoride from both varnishes. The NH4F varnish was found to be superior to Duraphat in terms of inhibiting artificial caries lesion formation (P less than 0.001).     

Studies of fluoride varnishes in Finland.

Despite the artificial fluoridation of drinking water in Kuopio, part of the children have high caries incidence. We therefore started our studies on fluoride varnishes in 1977 in an attempt to find a feasible means of applying fluoride topically in children at high risk of caries. In our first trial, the sodium fluoride varnish Duraphat was found to be effective in preventing caries, but the effectiveness of the silane fluoride varnish Fluor Protector could not be unequivocally established, despite the fact that Fluor Protector deposited markedly more fluoride in enamel than Duraphat. In a second study in children in a low-fluoride area, use of Duraphat was found to be more effective than fortnightly fluoride rinses or Fluor Protector. Increasing the frequency of application from two to four times a year did not increase the effectiveness of Duraphat even in highly caries-prone children in a 2-year trial. On the basis of peak values of fluoride in parotid saliva after application, use of either fluoride varnishes was considered safe. Although the fluoride content of the enamel remained elevated for at least two years after discontinuation of treatment with both varnishes, the caries preventive effect did not continue after the applications were stopped. This shows that increasing the fluoride content of enamel is not the main mechanism by which fluoride varnishes prevent caries, and that the applications need to be continued as long as caries is a problem.     

Effects of a sodium fluoride solution and a varnish with different fluoride concentrations on enamel remineralization in vitro

Abstract – To study the efficacy of sodium fluoride varnishes and a NaF solution in remineralization of enamel, 120 slabs of non-carious human enamel enamel were presoftened for 6 h and randomly divided into six groups. The slabs were stored in synthetic saliva for 9 days, except for a daily 30-min immersion in 0.1 M lactic acid-NaOH buffer. During the 9-day period, one group of the slabs received no treatment, and the rest were treated once or three times with 2.3% or 1.1% sodium fluoride varnish Duraphat, or nine times with a 0.1% NaF solution. Finally, the slabs were demineralized for 1 h, and the amount of dissolved Ca and F was determined. Microhardness of enamel was determined initially, after presoftening, after the 9- day period, and after the 1-h demineralization. All fluoride treatments prevented enamel softening almost completely during the 9 days, but the control slabs softened markedly. Fluoride varnishes were more effective than NaF solution. Three applications of 2.3% Duraphat were slightly more effective than any of the other varnish treatments, but one treatment with 2.3% varnish was not more effective than treatments with 1.1% varnish. Enamel treated three times with 1.1% varnish showed the greatest acid resistance during the 1-h demineralization. The results suggest that the efficacy of the varnish was not proportional to the fluoride concentration but rather to the number of applications. Fluoride uptake by enamel was greatest with the most concentrated varnish. Enamel solubility was not, however, directly proportional to the fluoride content of enamel.     

Effects of a sodium fluoride solution and a varnish with different fluoride concentrations on enamel remineralization in vitro

To study the efficacy of sodium fluoride varnishes and a NaF solution in remineralization of enamel, 120 slabs of non-carious human enamel enamel were presoftened for 6 h and randomly divided into six groups. The slabs were stored in synthetic saliva for 9 days, except for a daily 30-min immersion in 0.1 M lactic acid-NaOH buffer. During the 9-day period, one group of the slabs received no treatment, and the rest were treated once or three times with 2.3% or 1.1% sodium fluoride varnish Duraphat, or nine times with a 0.1% NaF solution. Finally, the slabs were demineralized for 1 h, and the amount of dissolved Ca and F was determined. Microhardness of enamel was determined initially, after presoftening, after the 9-day period, and after the 1-h demineralization. All fluoride treatments prevented enamel softening almost completely during the 9 days, but the control slabs softened markedly. Fluoride varnishes were more effective than NaF solution. Three applications of 2.3% Duraphat were slightly more effective than any of the other varnish treatments, but one treatment with 2.3% varnish was not more effective than treatments with 1.1% varnish. Enamel treated three times with 1.1% varnish showed the greatest acid resistance during the 1-h demineralization. The results suggest that the efficacy of the varnish was not proportional to the fluoride concentration but rather to the number of applications. Fluoride uptake by enamel was greatest with the most concentrated varnish. Enamel solubility was not, however, directly proportional to the fluoride content of enamel.     

Effect of Nd:YAG laser combined with fluoride on the prevention of primary tooth enamel demineralization

Most studies dealing with the caries preventive action of Nd:YAG laser have been done in permanent teeth and studies on primary teeth are still lacking. The aim of this study was to evaluate in vitro the effect of Nd:YAG laser combined or not with fluoride sources on the acid resistance of primary tooth enamel after artificial caries induction by assessing longitudinal microhardness and demineralization depth. Sixty enamel blocks obtained from the buccal/lingual surface of exfoliated human primary molars were coated with nail polish/wax, leaving only a 9 mm2 area exposed on the outer enamel surface, and randomly assigned to 6 groups (n=10) according to the type of treatment: C-control (no treatment); APF: 1.23% acidulated phosphate fluoride gel; FV: 5% fluoride varnish; L: Nd:YAG laser 0.5 W/10 Hz in contact mode; APFL: fluoride gel + laser; FVL: fluoride varnish + laser. After treatment, the specimens were subjected to a des-remineralization cycle for induction of artificial caries lesions. Longitudinal microhardness data (%LMC) were analyzed by the Kruskal-Wallis test and demineralization depth data were analyzed by oneway ANOVA and Fisher's LSD test (á=0.05). APFL and APF groups presented the lowest percentage of microhardness change (p<0.05). Demineralization depth was smaller in all treated groups compared with the untreated control. In conclusion, Nd:YAG laser combined or not with fluoride gel/varnish was not more effective than fluoride alone to prevent enamel demineralization within the experimental period.     

Differences in loosely bound fluoride formation and anticaries effect of resin‐based fluoride varnishes

International Journal of Paediatric Dentistry 2013; 23: 166–172 Objective. Our in vitro study evaluated calcium fluoride formation in enamel and the anticaries effect of seven resin‐based varnishes under cariogenic challenge. Methods. Enamel blocks were subjected to pH cycling. The experimental groups received fluoride varnish application, the positive control received topical fluoride gel treatment, and the negative control did not receive any treatment. The pH cycling surface hardness (SH₁) and integrated loss of subsurface hardness (ΔKHN) were then determined. We measured the amount of fluoride released into the demineralizing and remineralizing (DE–RE) solutions used in pH cycling. The fluoride concentration in the enamel was determined 24 h after application of the products as loosely bound fluoride and firmly bound fluoride. Results. Higher deposits of loosely bound fluoride were observed for Duofluorid, followed by Biophat. For Duraphat, Bifluorid, Duraflur, and Duofluorid, no difference was observed in the SH₁ and ΔKHN values, with the lowest mineral loss compared to the other groups. The Bifluorid and Duofluorid groups released high fluoride amounts into the DE–RE, and statistically significant difference was noted between them. Conclusions. The anticaries effect showed no correlation with higher deposited fluoride amounts, resin type, or fluoride source.     

Effect of a 4% titanium tetrafluoride (TiF4) varnish on demineralisation and remineralisation of bovine enamel in vitro

OBJECTIVES: This in vitro study assessed the effect of a 4% TiF4 varnish on demineralisation and remineralisation of sound enamel and artificial carious enamel lesions, respectively. METHODS: Bovine sound and carious enamel (n=110) were randomly allocated to each type of varnish: Duraphat-D (NaF, 2.26%F, pH 4.5, Colgate-Brazil, n=30), Duofluorid-F (NaF, 2.71%F, pH 8.0, FGM-Brazil, n=30), TiF4-T (2.45%F, pH 1.0, FGM-Brazil, n=30) and no-fluoride-P (FGM-Brazil, pH 5.0, n=20). For the formation of artificial enamel caries, half of the blocks were immersed in 32 mL buffer acetate solution (16 h), whereas the other half was maintained sound. The varnishes were applied onto the enamel surfaces. Thus, the samples were subjected to pH cycles (37 degrees C) for 7 days. The response variables tested were surface and cross-sectional hardness. Data were tested using Kruskal-Wallis test (p<0.05). RESULTS: All F varnishes significantly reduced demineralisation and increased remineralisation in comparison to placebo. The TiF4 did not significantly reduce the surface enamel softening when compared with the other F varnishes, but it decreased the loss of subsurface hardness to the same extent. In enamel blocks with previous artificial carious lesions, the TiF4 significantly improved the rehardening compared to the other varnishes up to 30 microm depth. CONCLUSIONS: The TiF4 varnish was able to decrease the demineralisation and increase the remineralisation of previously sound and carious enamel, respectively. It was equally effective compared to NaF varnishes on reducing the demineralisation at subsurface, but it was more effective on improving the remineralisation at surface and subsurface.     

Effect of a fluoride varnish on demineralization adjacent to orthodontic brackets.

Home fluoride regimens have long been used to reduce the amount of demineralization adjacent to orthodontic appliances. In the absence of patient compliance, another method of applying the fluoride must be used. The purpose of this study was to evaluate, in vitro, the ability of a fluoride varnish, Duraflor, to directly inhibit demineralization of enamel surrounding orthodontic brackets. Brackets were bonded to 36 extracted human canines and premolars with a traditional composite resin and randomly assigned to three equal groups of twelve. Group 1 served as the control with no topical application after bonding. Group 2 was treated with a single application of a nonfluoridated placebo varnish. Group 3 was treated with a single application of Duraflor. All groups were cycled in an artificial caries challenge for 1 hour two times daily for 37 days and were brushed with a medium bristled toothbrush to simulate mechanical wear of the varnish. Demineralization of enamel was evaluated in longitudinal buccolingual tooth sections using polarized light microscopy. Both average depth and area of demineralization were measured with a sonic digitizer. ANOVA (P 相似文献