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。     

氟化泡沫防止正畸固定矫治患者釉质脱矿的实验研究

目的观察氟化泡沫在酸性环境下抑制牙釉质脱矿的作用。方法样本制备后,实验组样本用氟化泡沫处理,对照组藻酸盐印模封闭处理。显微硬度计分别测定人工龋蚀前后样本釉质表面显微硬度,甲基麝香草酚蓝法测定样本酸蚀钙溶出量。结果实验组钙溶出量和釉质显微硬度变化与对照组比较有统计学差异(P<0.01)。结论氟化泡沫能抑制酸性环境下的牙釉质脱矿,能防止正畸固定矫治患者釉质脱矿。     

局部用奥威尔凝胶对酸性饮料导致年轻恒牙脱矿和再矿化的影响

目的比较局部使用奥威尔凝胶或氟保护漆对年轻恒牙抵抗饮料酸蚀及酸蚀后脱矿釉质再矿化的影响。方法观测年轻恒牙的釉质经饮料浸泡后再经奥威尔凝胶或氟保护漆局部处理,或奥威尔凝胶及氟保护漆处理后再经饮料浸泡的表面显微硬度（SMH）变化;应用扫描电子显微镜（SEM）观察各组釉质的表面形态。结果饮料浸泡后再经奥威尔凝胶或氟保护漆局部处理的年轻恒牙,其釉质的SMH明显增加（P<0.05）,奥威尔凝胶组的SMH高于氟保护漆组（P<0.05）。奥威尔凝胶或氟保护漆处理釉质表面后再经饮料浸泡,奥威尔凝胶组的SMH高于氟保护漆组（P<0.05）。SEM下可见各组釉质表面经饮料及奥威尔凝胶或氟保护漆处理后呈现不同程度的釉质溶解和再矿化。结论年轻恒牙釉质表面应用奥威尔凝胶可以增强釉质对饮料酸蚀的抵抗作用,促进脱矿釉质的再矿化。     

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。     

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。     

镧、钙、氟对釉质脱矿的影响——显微硬度测定

目的：比较镧,钙,氟对人牙釉质酸蚀脱矿影响,为镧的应用研究提供实验依据,方法：酸性凝胶化学致龋,测定釉质脱矿区剖面显微硬度,逐步单因素方差分析其显微硬度值,结果：釉质表层下25－125um范围内,镧处理组,氟处理组的硬度值高于对照组,25－75um范围内,洎 的硬度值高于钙处理组,50－150um范围内,钙处理组的硬度值高于对照组,氟处理组的硬度值高于镧处理组,结论：脱矿凝胶中加入1g/L的Ca2 ,La3 ,F-均阻止釉质硬度的下降,氟的作用最强,钙的作用最弱,镧的处理界于氟和钙之间。     

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     

局部运用氟制剂抑制牙本质脱矿的体外研究

目的本实验评估体外脱矿环境中几种氟制剂对牙本质的脱钙作用。方法20个标本随机分成5组:0.1%氟保护漆组,0.5%氟保护漆组,0.6%氟化泡沫组,1.23%氟化泡沫组,空白对照组。用钙体外临床诊断试剂盒检测龋蚀液中Ca2 浓度值,计算出每组在各时间点牙本质钙溶出的总量。并将标本制成磨片,在体视显微镜下观察龋损情况。结果氟制剂组抑制钙溶出效果明显优于空白对照组,氟保护漆组优于氟化泡沫组,氟保护漆组之间无显著性差异,氟化泡沫组之间无显著性差异。结论各种氟制剂均有防止牙本质脱钙作用,0.1%氟保护漆抑制牙本质脱钙作用最显著。     

镧、钙、氟对釉质脱矿的影响——显微硬度测定

目的 :比较镧、钙、氟对人牙釉质酸蚀脱矿影响 ,为镧的应用研究提供实验依据。方法 :酸性凝胶化学致龋 ,测定釉质脱矿区剖面显微硬度 ,逐点单因素方差分析其显微硬度值。结果 :釉质表层下 2 5～ 15 0 μm范围内 ,镧处理组、氟处理组的硬度值高于对照组 ;2 5～ 75 μm范围内 ,镧处理组的硬度值高于钙处理组 ;5 0～ 15 0 μm范围内 ,钙处理组的硬度值高于对照组 ,氟处理组的硬度值高于镧处理组。结论 :脱矿凝胶中加入 1g/L的Ca2 +、La3 +、F-均阻止釉质硬度的下降 ,氟的作用最强 ,钙的作用最弱 ,镧的作用界于氟和钙之间。     

氟保护漆抑制酸性含乳饮料对乳牙釉质脱矿作用的研究

目的:观察氟保护漆对乳牙釉质在酸性含乳饮料中脱矿的抑制作用,为其在婴幼儿龋病群防中的应用提供实验依据.方法:选取无龋、无裂纹、无釉质发育缺陷的乳中切牙30个,分别制备唇侧釉质块后随机分为人工唾液对照组(A组)、直接酸性含乳饮料浸泡组(B组)、0.1％氟保护漆处理后酸性含乳饮料浸泡组(C组),每组10个标本.A组置于10 mL 37℃恒温的人工唾液中浸泡4d;B、C两组置于10 mL 37℃恒温的酸性含乳饮料中浸泡,每天浸泡3次,每次均以间断法(浸泡2 min,取出1 min,再浸泡,循环5次共10 min),连续浸泡4d.上述浸泡处理后的3组釉质标本分别用场发射扫描电镜、能谱分析仪检测釉质表面的形态变化及Ca2+、P3+含量(重量百分比)和钙/磷比值,结果用SPSS 11.5软件进行统计分析.结果:与对照组相比,酸性含乳饮料浸泡可致乳牙釉质表面脱矿,Ca2+、P3+含量明显降低(P＜0.05);氟保护漆处理后可改善釉质表面的脱矿程度,并使晶体颗粒体积增大,其表面Ca2+、p3+含量的降低程度也低于酸性含乳饮料浸泡组,差异有统计学意义(P＜0.05).结论:酸性含乳饮料对乳牙釉质表面有较强的酸蚀脱矿作用;釉质表面应用氟保护漆可在一定程度上抑制乳牙釉质在酸性含乳饮料中的脱矿,但不能完全抵御饮料的酸蚀.     

氟化微量元素制剂对变形链球菌抑制作用的实验研究

目的 :比较氟化微量元素制剂对变形链球菌的抑制作用 ,为找到低毒高效的抑龋制剂提供依据。方法 :五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 )和氟化钠分别以不同浓度加入含变形链球菌悬液的BHI培养基中 ,采用厌氧菌连续培养技术 ,观察菌落计数变化。结果 :氟化锌、氟化亚锡的抑菌强度在各浓度时均最强 (p <0 .0 5 ) ,且含较低氟浓度的氟化锌、氟化亚锡制剂比含较高氟浓度的氟化钠制剂抑菌强度更高。结论 :锡、锌等微量元素可明显提高氟化物的抑菌生物活性 ,在抑菌防龋方面 ,氟化微量元素具有广泛的应用前景     

Uptake of fluoride by sound and artificially carious enamel in vitro following application of topical sodium and amine fluorides

The aim of this investigation was to compare fluoride uptake and retention by sound and artificially carious enamel, after the topical application of a neutral sodium fluoride solution (NaF) or a commercial preparation containing aqueous amine fluorides (AF) 297 and 335 (Elmex Fluid, GABA International, Basel, Switzerland). Ten pairs of extracted premolars were used, one of each pair being treated with NaF and the other with AF. A lactic acid gel technique was used to produce artificial caries lesions on one-half of the buccal surface of the premolar crowns. Estimates at selected depths of pretreatment fluoride concentration, uptake and retention were made using a step-wise acid-etch sampling technique. AF produced much greater uptake than NaF, the difference being most marked in the deeper layers of the artificial lesions, suggesting that the amine fluorides had a strong affinity for demineralized enamel. After storage in normal saline for 1 week during which partial loss of the acquired fluoride occurred, the percentages retained ranged from 37 (NaF) to 65 percent (AF). It was concluded that AF enhanced both uptake and retention of fluoride by (artificial) early enamel caries lesions.     

氟化微量元素对变形链球菌葡萄糖基转移酶影响的比较研究

目的比较氟化微量元素制剂对变形链球菌葡萄糖基转移酶活性的抑制作用。方法含相同氟浓度的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)和氟化钠分别加入到含变形链球菌悬液的TYC培养基中,采用Ne-son-Somogyi法,观察变形链球菌葡萄糖基转移酶活性的变化。结果氟化钠、氟化锌、氟化锶、氟化亚锡、氟化镧、氟钼酸铵制剂均有抑制变形链球菌ATCC25175葡萄糖基转移酶活性的作用,其中尤以氟化亚锡抑制作用最强(P<0.05)。结论锡可提高氟化物的防龋生物活性,在抑菌防龋方面,氟化微量元素有广泛的应用前景。     

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。     

The protective effect of TiF4, SnF2 and NaF on erosion of enamel by hydrochloric acid in vitro measured by white light interferometry

The purpose of this in vitro study was to compare the protective effect of TiF4, SnF2 and NaF (all 0.5 M F) on the development of erosion-like lesions in human dental enamel. Four enamel specimens from each of 6 extracted molars were polished and embedded in epoxy resin. The enamel surfaces of 3 specimens from each tooth were treated with the different fluoride solutions for 2 min. Following fluoride treatments, the specimens were immersed in 0.01 M HCl (pH 2.0), for 2, 4 and 6 min in order to mimic a gastric reflux situation. One specimen from each tooth was used as a control and was only exposed to acid. The etching depths (in micrometres) after 6 min were: TiF4 0.8 (SD 0.8), SnF2 3.5 (SD 0.7), NaF 5.3 (SD 0.4), and 7.0 (SD 0.3) for the control specimens. Compared to the control, TiF(4) protected the enamel surface from acid attack almost completely (88%), while SnF2 reduced the etch depth after 6 min by 50% and NaF by 25%.     

Topical fluorides in caries prevention and management: a North American perspective.

A review of evidence-based literature indicates incomplete evidence for the efficacy of most measures currently used for caries prevention, with the exception of fluoride varnishes and the use of fluoride-based interventions for patients with hyposalivation. Not all fluoride agents and treatments are equal. Different fluoride compounds, different vehicles, and vastly different concentrations have been used with different frequencies and durations of application. These variables can influence the clinical outcome with respect to caries prevention and management. The efficacy of topical fluoride in caries prevention depends on a) the concentration of fluoride used, b) the frequency and duration of application, and to a certain extent, c) the specific fluoride compound used. The more concentrated the fluoride and the greater the frequency of application, the greater the caries reduction. Factors besides efficacy, such as practicality, cost, and compliance, influence the clinician's choice of preventive therapy. For noncavitated smooth surface carious lesions in a moderate caries-risk patient, the appropriate fluoride regimen would be semiannual professional topical application of a fluoride varnish containing 5 percent NaF (22,600 ppm of fluoride). In addition, the patient should use twice or thrice daily for at least one minute a fluoridated dentifrice containing NaF, MFP, or SnF2 (1,000-1,500 ppm of fluoride), and once daily for one minute a fluoride mouthrinse containing .05 percent NaF (230 ppm of fluoride). If the noncavitated carious lesion involves a pit or fissure, the application of an occlusal sealant would be the most appropriate preventive therapy. The management of the high caries-risk patient requires the use of several preventive interventions and behavioral modification, besides the use of topical fluorides. For children over six years of age and adults, both office and self-applied topical fluoride treatments are recommended. For office fluoride therapy at the initial visit, a high-concentration agent, either a 1.23 percent F APF gel (12,300 ppm of fluoride) for four minutes in a tray or a 5 percent NaF varnish (22,600 ppm of fluoride), should be applied directly to the teeth four times per year. Self-applied fluoride therapy should consist of the daily five-minute application of 1.1 percent NaF or APF gel (5,000 ppm of fluoride) in a custom-fitted tray. For those who cannot tolerate a tray delivery owing to gagging or nausea, a daily 0.05 percent NaF rinse (230 ppm of fluoride) for 1 minute is a less effective alternative. In addition, the patient should use twice or thrice daily for at least 1 minute a fluoridated dentifrice as described above for treatment of noncavitated carious lesions. In order to avoid unintentional ingestion and the risk of fluorosis in children under six years of age, fluoride rinses and gels should not be used at home. Furthermore, when using a fluoride dentifrice, such children should apply only a pea-size portion on the brush, should be instructed not to eat or swallow the paste, and should expectorate thoroughly after brushing. Toothbrushing should be done under parental supervision. To avoid etching of porcelain crowns and facings, neutral NaF is indicated in preference to APF gels for those patients who have such restorations and are applying the gel daily. The rationale for these recommendations is discussed. Important deficiencies in our knowledge that require further research on topical fluoride therapy in populations with specific needs are identified.     

A study investigating the formation of artificial sub-surface enamel caries-like lesions in deciduous and permanent teeth in the presence and absence of fluoride

OBJECTIVES: Clinical and in situ studies have shown that caries formation and progression is faster in primary than in permanent teeth. Ambient levels of fluoride are also known to influence the processes of carious lesion formation. The aims were, firstly to investigate the incidence of artificial sub-surface caries lesion formation in the enamel of deciduous and permanent teeth in vitro. Secondly, to compare quantitatively the mineral content and distribution of these lesions and assess the possible influence of fluoride upon the lesion parameters. METHODS: Twenty primary molars and 20 permanent premolars were randomly assigned to one of four experimental groups. Samples in each experimental group were immersed in a 0.05M lactic acid gel (6% w/v hydroxyethyl cellulose, pH 4.5) either in the absence or presence of fluoride for 7 days. Subsequently, lesion parameters of mineral loss (vol x % microm) and lesion depth (microm) were assessed by transverse microradiography and image analysis. RESULTS: No significant differences existed between the lesion parameters of permanent and primary teeth (P=0.20). Irrespective of tooth type, lesion parameters were significantly reduced in samples demineralised in the presence of fluoride (P< or =0.002). CONCLUSIONS: Fluoride significantly reduces the severity of sub-surface caries lesions formed in vitro and in contrary to previous studies, there were no significant differences in lesions parameters between permanent and primary teeth.