成膜基质对氟化物涂膜抑制釉质早期龋的效果

目的:比较含不同成膜基质的氟化物涂膜抑制釉质早期龋的效果。方法:将制备的90个釉质试样块随机分成6组,分别应用以5种成膜基质(珂巴树脂、渗透型丙烯酸树脂、甲基丙烯酸乙酯共聚树脂、聚合松香、聚乙烯醇缩丁醛)配制的氟涂膜材料和Duraphat氟涂膜进行处理。采用荧光显微镜和显微硬度计测定各组釉质试样块在pH循环前后的荧光值和硬度值的变化;并通过偏光显微镜观察其脱矿深度。结果:pH循环后各组釉质试样块的荧光值和硬度值均较pH循环前明显降低,其中渗透型丙烯酸组与其他组相比,荧光损失率和硬度值变化率最小,与其他各组相比差异均有统计学意义(P<0.05);偏光显微镜观察显示:各组釉质表面均无实质性缺损,渗透型丙烯酸组釉质脱矿深度最浅。结论:氟化物涂膜具有明显的抑制釉质脱矿的作用,含渗透型丙烯酸树脂的氟涂膜效果最好。     

矿化液、低浓度氟化物溶液和氟泡沫再矿化作用比较

目的本研究对矿化液、低浓度氟化物溶液和氟泡沫再矿化作用进行了比较,从而寻找出一种再矿化效果较好的制剂.方法采用实验室研究,分别用三种制剂处理表面脱矿釉质.应用显微硬度仪检测处理前后的釉质表面硬度值,通过对比前后硬度差异反映脱矿釉质的再矿化的情况.结果矿化液处理后的釉质表面硬度明显增加,有显著性统计学意义.低浓度氟化物溶液和氟泡沫处理后釉质的表面硬度无明显改变.结论在体外,矿化液的再矿化效果优于低浓度氟化物溶液和氟泡沫.它可用于治疗正畸过程中早期釉质脱矿.     

渗透性树脂作用于脱矿釉质的扫描电镜观察

目的:用扫描电镜观察渗透性树脂作用于脱矿釉质表面的微观形态。方法:将离体牙12颗分为6颗健康釉质组,6颗脱矿釉质组。建立人工脱矿模型。对脱矿釉质表面进行光固化渗透树脂治疗,然后按照电镜标本制作要求,脱水喷碳,扫描电镜观察渗透性树脂使用套装中的盐酸凝胶对釉质表面处理前后及渗透性树脂作用于脱矿釉质表面的微观结构。结果:盐酸凝胶在健康牙釉质表面脱矿深度只有10 μm左右,不会对健康釉质造成伤害;盐酸凝胶可以彻底清除脱矿釉质表面的钙化层,使渗透性树脂充分渗透入脱矿釉质体部,但在树脂突之间及釉质体部偶尔可见裂隙存在。结论:渗透性树脂可以在脱矿釉质表面形成规则的网状结构,良好的封闭了脱矿釉质表面。     

氟纳米羟基磷灰石对早期釉质龋再矿化影响的研究

目的:研究氟纳米羟基磷灰石对早期釉质龋再矿化的影响,比较它与纳米羟基磷灰石、氟化钠和人工唾液的再矿化效果。方法:选取新鲜拔出的牛切牙40颗,制成人工龋模型,露出唇侧面,其余部分涂布双层指甲油。置于盛有脱矿液的容器中37℃脱矿3d,使用显微硬度仪测量脱矿后釉质的显微硬度。扫描电镜下观察脱矿后的釉质表面的平滑状态。然后随机分为4组。用软毛刷将相应试剂涂刷在釉质表面,3次/d,3～4min/次。人工唾液组直接将釉质块浸泡其中。10d后进行显微硬度和扫描电镜观察。实验前后统计采用配对t检验。结果:氟纳米羟基磷灰石组的显微硬度较脱矿后和对照组硬度值增加,有统计学意义(P<0.05),扫描电镜观察釉质表面变平滑。结论:氟纳米羟基磷灰石对早期釉质龋的再矿化效果较好。     

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。     

氟保护漆对正畸牙釉质脱矿影响的研究

目的探讨含氟保护漆对正畸牙齿托槽周围釉质脱矿的影响。方法选用临床需拔牙正畸患者(至少拔除2颗前磨牙者),同一患者的前磨牙随机分为2组,观察组在其托槽周围牙面涂布含氟保护漆,对照组不加任何处理。85～95 d后,临床观察实验牙有无脱矿,同时,拔除受试牙,显微硬度计测定釉质脱矿的程度,偏光显微镜观察釉质脱矿病损的分布并测量龋损深度,扫描电镜观察表面形貌改变。结果实验组脱矿率为11.1%,对照组脱矿率为44.4%(P<0.05);观察组显微硬度高于对照组(P<0.05)。对照组样本出现明显的釉质脱矿,龋损的平均深度为(80.35±5.42)μm,而实验组中龋损的平均深度仅为(40.24±2.76)μm,两者有统计学差异(P<0.05)。扫描电镜下对照组出现了典型的脱矿结构,表面呈现孔隙凹坑的不规则外形,而处理组表面较为完整。结论氟保护漆能有效地防治正畸治疗中釉质的脱矿。     

渗透树脂治疗乳牙釉质早期龋的体外研究

目的：探讨渗透树脂治疗人工脱矿乳牙釉质早期龋对其釉质显微硬度的影响。方法：选取5～7岁儿童因滞留拔除的无龋下颌乳中切牙21颗,制备人工脱矿釉质模型后,随机将其分为空白对照组、脱矿组、渗透树脂治疗组,每组7个样本,采用显微硬度测试仪测量各组牙釉质显微硬度,观察釉质显微硬度的变化。结果：空白对照组、渗透树脂治疗组牙釉质表面显微硬度明显高于脱矿组,差异具有统计学意义（P＜0．01）;渗透树脂治疗组显微硬度低于空白对照组,差异具有统计学意义（P＜0．01）。结论：乳牙釉质脱矿后牙釉质表面显微硬度降低,渗透树脂治疗釉质脱矿可提高牙釉质表面的显微硬度。     

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...     

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     

牙釉质表面经中性氟化钠处理后的扫描电镜观察和硬度改变

用扫描电镜和显微硬度计研究经中性氟化钠处理后釉质的表现和显微硬度,结果表明釉质表面有CaF_2颗粒沉积,其形成与氟浓度,处理时间,氟化纳剂型及釉质表面状况有关。氟化纳使经乳酸脱矿的釉质的硬度明显上升,再次脱矿后,其硬度虽有下降却无统计学意义。说明F~-不仅使Ca~(2+)、PO_4~(3-)等沉积于釉质表面使其再矿化,且能降低其溶解速度,在抑制釉质再脱矿方面发挥作用。     

IN VITRO ASSESSMENT OF AN EXPERIMENTAL COAT APPLIED OVER FLUORIDE VARNISHES

Objective:

The time of contact between the product and enamel surface is important in ensuring the efficacy of fluoride varnishes. Thus, some alternatives could avoid fluoride loss to saliva and improve the anticariogenic action of the product. This study evaluated the effect of an experimental coat on the anticariogenic action of fluoride varnishes.

Material and Methods:

Enamel bovine blocks were selected by evaluating surface microhardness and randomized into five groups (n=24): placebo, Duraphat™, Duraphat™ with coat, Duofluorid™ and Duofluorid™ with coat. Twelve blocks from each group were used to analyze calcium fluoride (CaF₂) formed on enamel after treatment. The other 12 blocks were subjected to pH cycling for 7 days. The varnishes were kept on enamel for 6 h. Next, the percentage change of surface microhardness (%SMHC) and mineral loss (ΔZ) were calculated. CaF₂ retained and fluoride present in the pH-cycled solutions were also measured.

Results:

The use of the coat did not decrease %SMHC and ΔZ, but all fluoride varnishes had better results when compared to the placebo (ANOVA and Kruskal-Wallis, respectively). The values from CaF₂ formed were higher compared to the values of CaF₂ retained (non-paired t test, p<0.05). There was a trend to decrease the amount of F in the solutions at the end of pH cycling (Kruskal-Wallis, p<0.05).

Conclusions:

Although the experimental coat increased the formation of CaF₂ on the enamel surface, it did not significantly improve the anticariogenic action of fluoride varnishes.     

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.     

Fluoride varnishes containing sodium trimetaphosphate reduce enamel demineralization in vitro

Objective: This study evaluated the effects of fluoride varnishes containing sodium trimetaphosphate (TMP) on bovine enamel demineralization in vitro.

Material and methods: Enamel bovine discs were randomly assigned into six groups (n?=?20/group): placebo, 2.5% NaF, 2.5% NaF/5% TMP, 5% NaF, 5% NaF/5% TMP, and a commercial formulation (Duraphat, 5% NaF). Varnishes were applied on all enamel discs and kept for 6?h. Loosely and firmly bound fluoride formed on/in enamel after treatment were analyzed in 10 discs from each group. The other 10 discs were subjected to a pH-cycling regimen for 7 days, and analyzed for surface (SH) and cross-sectional hardness (ΔKHN), as well as for loosely and firmly bound fluoride in/on enamel. Data were analyzed by analysis of variance (ANOVA) followed by Student–Newman–Keuls’ test (p?Results: The lowest SH change and ΔKHN were observed for the 5%NaF/5%TMP varnish, which was significantly different from all the other groups. Both fluoridated varnishes containing TMP promoted significantly lower SH change and ΔKHN when compared with their counterparts without TMP. Loosely and firmly bound fluoride was significantly lower in groups treated with varnishes containing TMP.

Conclusion: TMP and fluoride added to varnishes have a synergistic effect against enamel demineralization in vitro.     

中子活化法测定氟保护漆体内释放的临床研究

目的利用中子活化分析法测定氟保护漆应用前、后牙釉质中氟含量的变化。方法选择15例患者,以临床同一患者将要拔除的2颗下颌乳中切牙为研究对象,1颗拔除作为对照,另1颗涂布口腔专用氟保护漆24h后再拔除,测定2颗牙牙釉质中氟的含量,进行统计学分析。结果试验组氟化物的含量为(142.78±42.25)μg/g,对照组为(119.62±38.62)μg/g。试验组中氟的含量大于对照组,差异有统计学意义(P<0.05)。结论氟保护漆的应用能有效增加牙齿硬组织中氟的含量。     

Deposition of fluoride on enamel surfaces released from varnishes is limited to vicinity of fluoridation site

The aim of the in-situ study was to determine fluoride uptake in non-fluoridated, demineralized enamel after application of fluoride varnishes on enamel samples located at various distances from the non-fluoridated samples. All enamel samples used were demineralized with acidic hydroxyethylcellulose before the experiment. Intra-oral appliances were worn by ten volunteers in three series: (1, Mirafluorid, 0.15% F; 2, Duraphat, 2.3% F and 3, unfluoridated controls) of 6 days each. Each two enamel samples were prepared from 30 bovine incisors. One sample was used for the determination of baseline fluoride content (BFC); the other was treated according to the respective series and fixed in the intra-oral appliance for 6 days. Additionally, from 120 incisors, each four enamel samples were prepared (one for BFC). Three samples (a–c) were placed into each appliance at different sites: (a) directly neighboured to the fluoridated specimen (=next), (b) at 1-cm distance (=1 cm) and (c) in the opposite buccal aspect of the appliance (=opposite). At these sites, new unfluoridated samples were placed at days 1, 3 and 5, which were left in place for 1 day. The volunteers brushed their teeth and the samples with fluoridated toothpaste twice per day. Both the KOH-soluble and structurally bound fluoride were determined in all samples to determine fluoride uptake and were statistically analyzed. One day, after fluoridation with Duraphat, KOH-soluble fluoride uptake in specimen a (=next) was significantly higher compared to the corresponding samples of both the control and Mirafluorid series, which in turn were not significantly different from each other. At all other sites and time points, fluoride uptake in the enamel samples were not different from controls for both fluoride varnishes. Within the first day after application, intra-oral-fluoride release from the tested fluoride varnish Duraphat leads to KOH-soluble fluoride uptake only in enamel samples located in close vicinity to the fluoridation site.     

Evaluation of fluoride release from commercially available fluoride varnishes.

BACKGROUND: The authors conducted a study to evaluate the fluoride released from two fluoride varnishes: Duraphat (Colgate-Palmolive Co., New York) and Duraflor (Pharmascience Inc., Montreal). Fluoride-release information for these commercially available dental products has not been available to clinicians treating children at risk of developing dental caries. METHODS: The authors painted enamel slabs from primary molar teeth with 30 milligrams of two varnishes: nine samples received Duraphat, nine received Duraflor and five samples served as controls. The samples were immersed in buffered calcium phosphate solution (pH, 6.0) to simulate the oral environment, and the amount of fluoride released was measured weekly for six months. RESULTS: From week 4 to the end of the study, Duraphat released significantly more fluoride than Duraflor. Duraflor continued releasing fluoride until week 19, while Duraphat released fluoride until week 28. The authors found greater variability in the release of fluoride from the Duraflor samples than from the Duraphat samples. Two-thirds of the fluoride was released from both products by the end of the study. CONCLUSIONS: Both varnishes released fluoride for five to six months. However, the two products exhibited differences in their release kinetics. CLINICAL IMPLICATIONS: These findings show that either of the fluoride varnishes may maintain a high level of fluoride in plaque fluid around primary teeth over a long period, but that the availability of fluoride may vary among tubes of the same product and between the two products themselves.     

In vitro fluoride uptake, distribution and retention by human enamel after 1- and 24-hour application of various topical fluoride agents

The in vitro fluoride acquisition by human enamel after a 1-hour and 24-hour application of APF, Duraphat (a resin varnish) or Fluor Protector (a polyurethane varnish) and subjection to various procedures was determined. Fluoride acquisition was the greatest in teeth treated with Fluor Protector and the least in APF-treated teeth. Fluoride uptake and distribution were increased by prolonging the contact time between the varnishes and enamel, and fluoride retention was decreased after subsequent exposure to synthetic saliva.