Focus on Fluorides: Update on the Use of Fluoride for the Prevention of Dental Caries

Improving the efficacy of fluoride therapies reduces dental caries and lowers fluoride exposure.BackgroundFluoride is delivered to the teeth systemically or topically to aid in the prevention of dental caries. Systemic fluoride from ingested sources is in blood serum and can be deposited only in teeth that are forming in children. Topical fluoride is from sources such as community water, processed foods, beverages, toothpastes, mouthrinses, gels, foams, and varnishes. The United States Centers for Disease Control and Prevention (CDC) and the American Dental Association (ADA) have proposed changes in their long standing recommendations for the amount of fluoride in community drinking water in response to concerns about an increasing incidence of dental fluorosis in children. Current research is focused on the development of strategies to improve fluoride efficacy. The purpose of this update is to inform the reader about new research and policies related to the use of fluoride for the prevention of dental caries.MethodsReviews of the current research and recent evidence based systematic reviews on the topics of fluoride are presented. Topics discussed include: updates on community water fluoridation research and policies; available fluoride in dentifrices; fluoride varnish compositions, use, and recommendations; and other fluoride containing dental products. This update provides insights into current research and discusses proposed policy changes for the use of fluoride for the prevention of dental caries.ConclusionsThe dental profession is adjusting their recommendations for fluoride use based on current observations of the halo effect and subsequent outcomes. The research community is focused on improving the efficacy of fluoride therapies thus reducing dental caries and lowering the amount of fluoride required for efficacy.     

Evaluation of fluoride release from experimental TiF4 and NaF varnishes in vitro

Fluoride varnishes play an important role in the prevention of dental caries, promoting the inhibition of demineralization and the increase of remineralization.

Objective

This study aimed to analyze the amount of fluoride released into water and artificial saliva from experimental TiF₄ and NaF varnishes, with different concentrations, for 12 h.

Material and Methods

Fluoride varnishes were applied on acrylic blocks and then immersed in 10 ml of deionized water and artificial saliva in polystyrene bottles. The acrylic blocks were divided in seven groups (n=10): 1.55% TiF₄ varnish (0.95% F, pH 1.0); 3.10% TiF₄ varnish (1.90% F, pH 1.0); 3.10% and 4% TiF₄ varnish (2.45% F, pH 1.0); 2.10% NaF varnish (0.95% F, pH 5.0); 4.20% NaF varnish (1.90% F, pH 5.0); 5.42% NaF varnish (2.45% F, pH 5.0) and control (no treatment, n=5). The fluoride release was analyzed after 1/2, 1, 3, 6, 9 and 12 h of exposure. The analysis was performed using an ion-specific electrode coupled to a potentiometer. Two-way ANOVA and Bonferroni''s test were applied for the statistical analysis (p<0.05).

Results

TiF₄ varnishes released larger amounts of fluoride than NaF varnishes during the first 1/2 h, regardless of their concentration; 4% TiF₄ varnish released more fluoride than NaF varnishes for the first 6 h. The peak of fluoride release occurred at 3 h. There was a better dose-response relationship among the varnishes exposed to water than to artificial saliva.

Conclusions

The 3.10% and 4% TiF₄ -based varnishes have greater ability to release fluoride into water and artificial saliva compared to NaF varnish; however, more studies must be conducted to elucidate the mechanism of action of TiF₄ varnish on tooth surface.     

Alterations to Titanium Surface Depending on the Fluorides and Abrasives in Toothpaste

Fluoride and abrasives in toothpastes may cause corrosion and deterioration of the titanium used for implants and other prostheses. The purpose of this study was to investigate how the presence or absence and types of fluoride and abrasives affected the titanium surface texture. Brushing with toothpastes was performed on pure-titanium discs using an abrasive testing machine. Unprocessed titanium discs without brushing were used as control samples. Surface roughness, color, and gloss of titanium were measured and the differences compared with the control were analyzed. Additionally, titanium surfaces and abrasives in toothpastes were observed using a scanning electron microscope to compare the surface texture of each sample. Some toothpastes (abrasive+) significantly increased the difference in surface roughness, color, and gloss, compared with ultrapure water. Toothpaste (fluoride+/abrasive+) that had many polygonal abrasive particles led to the largest color differences and exhibited notable scratches and a larger number of contaminant- or corrosion-like black spots. In contrast, brushing with toothpaste without fluoride or abrasives (fluoride−/abrasive−) caused little change to the titanium surface. These results suggest that both fluoride and abrasives in toothpaste used for brushing may be factors that affect surface texture and corrosion resistance of titanium.     

大黄提取液对牙釉质脱矿的实验研究

目的:本实验了解大黄提取液对牙釉质的表面显微硬度值(surface microhardness, SMH)的影响,观察和评估大黄提取液对釉质脱矿影响的效果.方法:用去离子水做阴性对照、2%氟化钠做阳性对照、不同浓度大黄提取液处理釉质后进行脱矿,通过显微硬度的测定采用显微硬度仪测量处理前后显微硬度组釉质表面显微硬度值(surface microhardness, SMH)的变化.结果:三种浓度大黄提取液处理的釉质SMH值的降低程度都明显低于去离子水组(P＜0.01),而与2%氟化钠组相比无显著差异(P＞0.05),三组大黄相比也无显著差异(P＞0.05).结论:三组大黄提取液都具有抑制釉质脱矿作用.     

Fluoride Treatment and In Vitro Corrosion Behavior of Mg-Nd-Y-Zn-Zr Alloys Type

Fluoride conversion coatings on Mg present many advantages, among which one can find the reduction of the corrosion rate under “in vivo” or “in vitro” conditions and the promotion of the calcium phosphate deposition. Moreover, the fluoride ions released from MgF₂ do not present cytotoxic effects and inhibit the biofilm formation, and thus these treated alloys are very suitable for cardiovascular stents and biodegradable orthopedic implants. In this paper, the biodegradation behavior of four new magnesium biodegradable alloys that have been developed in the laboratory conditions, before and after surface modifications by fluoride conversion (and sandblasting) coatings, are analyzed. We performed structural and surface analysis (XRD, SEM, contact angle) before and after applying different surface treatments. Furthermore, we studied the electrochemical behavior and biodegradation of all experimental samples after immersion test performed in NaCl solution. For a better evaluation, we also used LM and SEM for evaluation of the corroded samples after immersion test. The results showed an improved corrosion resistance for HF treated alloy in the NaCl solution. The chemical composition, uniformity, thickness and stability of the layers generated on the surface of the alloys significantly influence their corrosion behavior. Our study reveals that HF treatment is a beneficial way to improve the biofunctional properties required for the studied magnesium alloys to be used as biomaterials for manufacturing the orthopedic implants.     

含氟牙膏对幼儿尿氟含量影响的初步研究

本实验观察了含氟牙膏对３１名４－５岁幼儿氟化物摄入水平的影响。结果发现幼儿使用含氟牙膏３月后尿氟浓度和２４小时尿氟排泄量为０．９６ｐｐｍ和０．５７ｍｇ;使用不含氟牙膏２月后为０．８４ｐｐｍ和０．４７ｍｇ;统计分析有显著差异。表明使用含氟牙膏可使幼儿氟摄入量增加。     

氟化物在儿童和青少年龋病防治中的应用

氟是人体所需的微量元素之一,适量的氟可预防龋病.氟化物的防龋机制体现在降低釉质溶解度,促进釉质再矿化,抑制细菌代谢和菌斑形成,影响牙体形态等方面.氟在龋病预防中的应用主要有氟的全身应用和局部应用.前者包括饮水氟化:将饮水中的F-调整到适宜质量浓度,使其能预防龋病,又不会导致并发症;食盐氟化:以食盐为载体加入氟化物;牛奶氟化:将适量氟化物添加到牛奶中以预防龋病;氟片和氟滴剂:兼有局部和全身的双重作用,以全身作用为主.全身用氟有优点有缺点,需根据不同国家和不同地区的实际情况选择性应用.后者包括个人用氟:使用含氟牙膏、含氟漱口水、含氟牙线和茶叶水漱口等多种方式;专业用氟:氟溶液涂布、含氟涂料、含氟凝胶、含氟泡沫、含氟材料和缓释氟材料等.局部用氟在临床及家庭预防中较为普遍,防龋效果较佳.     

无创渗透树脂材料修复早期乳牙邻面龋

背景：乳牙早期邻面龋因解剖位置的原因菌斑不易去除,常规再矿化治疗疗效不佳。目的：观察无创渗透树脂技术治疗乳牙早期邻面龋的临床疗效。方法：选择乳牙邻面早期龋的患牙120颗,随机分为渗透树脂组和流动树脂组,每组60颗,分别应用渗透树脂和流动树脂进行治疗,治疗后1年随访,对患者邻面龋的牙体形态、去除釉质脱矿造成的白垩色斑和色泽稳定性、继发龋和治疗成功率方面进行临床评价。结果与结论：两组患者在充填治疗后1年的疗效检查结果中发现,渗透树脂组邻面龋的牙体形态、去除釉质脱矿造成的白垩色斑以及色泽稳定性、继发龋方面均好于流动树脂组。渗透树脂组的治疗成功率96．7％远高于流动树脂组的76.7％,差异有显著性意义（P〈0．05）。无创渗透树脂材料是目前阻断龋病发展简便高效的方法。     

KIOM-79 prevents S100b-induced TGF-β1 and fibronectin expression in mouse mesangial cells

Aim of the study

In this study, we investigated whether KIOM-79 inhibits transforming growth factor-beta 1 (TGF-β1) and fibronectin expression in mouse mesangial cells cultured under S100b, a specific ligand of the receptor for advanced glycation end products (RAGE).

Materials and methods

Cell counting kit (CCK-8) assay was employed to evaluate the viability of KIOM-79-treated mesangial cells. The effect of KIOM-79 on S100b-induced TGF-β1 and fibronectin expression was investigated using RT-PCR, ELISA, and Western blot on mesangial cells.

Results

KIOM-79 (up to 50 μg/ml) appeared to have no effect on cell viability. S100b induced an increase in the expression TGF-β1 and fibronectin. Expression of TGF-β1 and fibronectin was inhibited significantly by KIOM-79 treatment in mesangial cells. KIOM-79 also inhibited the expression of NF-kB and inactivated p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK) 1/2 in mesangial cells. KIOM-79 pretreatment inhibited increased malondialdehyde (a product of lipid peroxidation and a marker for oxidative stress) levels in S100b-induced mesangial cells.

Conclusions

These data demonstrate that KIOM-79 inhibits expression of TGF-β1 and fibronectin through inactivation of MAPK/ERK1/2 signaling, reduction in malondiadehyde levels, and inhibition of NF-kB in mesangial cells cultured under diabetic conditions. KIOM-79 could be beneficial for preventing of the development of diabetic complications such as nephropathy.     

2002～2005年连云港市降氟改水工程水氟监测

目的:了解降氟改水工程后水氟含量动态变化规律。方法:用氟离子选择电极法检测水氟含量。结果:随时间的推移,降氟改水工程的水氟含量、水氟含量超标率均呈现上升趋势。结论:连云港市的病区地貌对水氟含量有一定影响,应持续监测,找出解决方法,保证供水质量。