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。     

多乐氟预防固定正畸矫治中牙釉质脱矿的临床研究

目的探讨多乐氟在固定正畸矫治过程中对牙釉质脱矿的预防作用。方法选择固定正畸矫治的恒牙列患者60例,采用自身对照,分为试验组和对照组,试验组粘接托槽后每3个月在托槽周围牙面涂布多乐氟,对照组粘接托槽后不做处理。在粘接托槽前和矫治第6、12个月分别对两组牙齿脱矿情况进行观察并记录牙釉质脱矿指数。结果矫治前试验组与对照组牙釉质脱矿指数差异无统计学意义(t=0.078,P>0.05),而矫治6个月(t=5.169,P<0.05)和12个月(t=6.031,P<0.05)时试验组的牙釉质脱矿指数均低于对照组,差异有统计学意义。结论固定矫治过程中应用多乐氟对牙釉质脱矿有一定预防作用。     

Effect of low level fluoride on demineralization kinetics of human dental enamel

The purpose of this study was to examine the effect of fluoride levels similar to those reported for saliva from low fluoridated and high fluoridated water areas on the demineralization of human permanent enamel. An adaptation of the method described by Robinson et al. was used. Sections of sound enamel were immersed in a vial containing demineralizing solution [2.0 mM Ca(NO₃)₂, 1.2 mM KHPO₄ in 50 mM acetic acid, pH 4.8] for 1 hour. The demineralizing solution contained 0, 0.02 or 0.05 ppm fluoride, added as NaF was prepared. Twenty microliters aliquots were taken from the demineralizing solution at the time point up to 1 hour, with a sampling frequency bias towards the early time point. The phosphate content of the removed sample was determined by colorimetry. When the mineral loss curves for fluoridated and non-fluoridated demineralizing solutions were compared, there were significant differences between both groups. There was a decrease in the net mineral loss when fluoride was used. This result suggested that salivary fluoride levels of 0.02 ppm and 0.05 ppm had a protective effect against demineralization.     

氟涂料预防正畸治疗中釉质脱矿的实验研究

目的　明确氟涂料对釉质脱矿进程的抑制效果。方法　研究分两组 ,实验组釉质表面覆盖氟涂料 ,对照组釉质表面暴露。经短期人工龋后 ,用偏振光显微镜观察托槽周围釉质脱矿病损的分布并测量病损体部深度。结果　对照组全部样本均出现较明显的釉质脱矿 ,病损体部的平均深度为 4 8.8± 15 .1微米 ,实验组中只有少数样本出现孤立的脱矿病损 ,其余样本没有发生明显的脱矿。结论　氟涂料对短期釉质脱矿的抑制作用较明显 ,可以成为正畸治疗中釉质脱矿的预防手段之一。     

光学相干断层成像检测牙釉质表层脱矿与再矿化的实验研究

目的利用光学相干断层成像技术(OCT)观察不同制剂对年轻恒牙釉脱矿和再矿化效果的影响。方法 将正畸拔除的年轻恒前磨牙制成60个釉质块,随机均分为4组。每天进行如下处理:A组蒸馏水湿敷30min;B组含氟牙膏湿敷30min;C组护牙素湿敷30min;D组多乐氟湿敷30min,置于脱矿液1.5h,最后置于人工唾液中22h。每个步骤间用去离子水冲洗实验样品。实验周期重复30天。在处理前和第 7、15、30天,使用扫频光源OCT完成对样本的扫描和成像,同时使用显微硬度计测量各样本表面的显微硬度。结果 釉质脱矿深度:7天后,A组与其他各组相互比较,差异有统计学意义( P <0.05),B、C、D组组间比较差异无统计学意义( P >0.05)。30天后,C组和D组比较,差异无统计学意义( P >0.05),其余各组之间两两比较,差异均有统计学意义( P <0.05)。显微硬度测量:30天后,各处理组较处理前显微硬度值降低,A组显微硬度值最低,C组与D组显微硬度值高于B组,且差异有统计学意义( P <0.05)。C组和D组间釉质块显微硬度值差异无统计学意义( P >0.05)。结论 OCT可以较准确的显示釉质脱矿部位,在早期龋的诊断方面具有临床意义。护牙素和多乐氟均能有效的抑制牙釉质表面脱矿。     

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。     

Efficacy of a slow-release device containing fluoride,xylitol and sorbitol in preventing infant caries

A novel slow-release administration device, the ''Fall-Asleep Pacifier'' (FAP), was studied as a prophylactic measure against mutans streptococcal oral infection and dental caries in a risk group of 1-year-old children by comparing the test (T, n = 34) and control (C, n = 88) groups in a prospective cohort study. In the T group the children received their fluoride tablets (Fludent^®, containing NaF corresp. 0.25 mg F^-, xylitol 159 mg and sorbitol 153 mg) in the evenings in FAP. In the C group the children received the same dose of Fludent^® crushed in food in the evenings. The proportion of children, whose plaque samples from the upper incisors were mutans streptococcus positive at the age of 24 months, was significantly (P &lt; 0.05) greater in group C (25%) than in group T (9%). The children in the T group developed significantly (P &lt; 0.001) less (none) new dentinal carious lesions in their primary dentitions than the children in the C group between 2 and 3½ years of age. Fifty-four percent of the children to whom the FAP was offered complied with regular use of it. The beneficial effect observed in the T group compared with the C group was apparently mostly due to the administration mode via FAP, which could prolong the intra-oral bio-availability of the prophylactic preparation.     

Duraphat在固定正畸治疗中抑制釉质脱矿的临床研究

目的 评估并探讨Duraphat在正畸治疗中抑制牙釉质脱矿的有效性.方法 选择固定矫治非拔牙患者36例共计288颗牙齿,每位患者的牙齿以上中线为界分为试验组与对照组,每组144颗牙,在正畸托槽粘接后于试验组的上颌前牙及前磨牙托槽周围牙面涂布Duraphat,每隔6个月复诊时涂布1次,对照组不做特殊处理.记录矫治6个月及12个月后牙釉质脱矿情况,并对数据进行统计分析.结果 矫治6个月及12个月后试验组牙齿的釉质脱矿指数分别为(0.142±0.215)分和(0.132±0.203)分;对照组釉质脱矿指数分别为(0.262±0.284)分和(0.369±0.417)分;矫治6个月及12个月后试验组釉质脱矿指数均明显低于对照例,差异有统计学意义(P＜0.05);但试验组矫治12个月时釉质脱矿情况与6个月时相比差异无统计学意义(t=1.915,P=0.058).结论 Duraphat对固定正畸过程中患者的釉质脱矿具有有效抑制作用,但尚不能完全阻止釉质脱矿的发生发展.     

氟涂料用于固定矫治后釉质脱矿再矿化治疗的效果

目的评价氟浓度为2.26 mg/mL的氟涂料应用于正畸固定矫治后釉质脱矿再矿化治疗的临床效果。方法对正畸固定矫治结束并拆除托槽的患者进行牙釉质脱矿状况检查,选择符合纳入标准的110例受试者,随机分为2组,试验组在脱矿牙面上涂布氟涂料,对照组在脱矿牙面上涂布蒸馏水,每个月1次,持续6个月,在拆除托槽当天（基线）和拆除托槽3个月、6个月分别对唇颊面釉质脱矿区域进行临床视诊检查,使用临床视诊指数进行评分。结果基线、3个月、6个月时试验组的视诊指数分别为（2.22±0.42）分、（2.18±0.43）分、（2.15±0.41）分;对照组的视诊指数分别为（2.15±0.36）分、（2.14±0.38）分、（2.14±0.38）分。基线（t=2.470,P=0.228）、拆除托槽3个月（t=0.651,P=0.516）及6个月（t=0.149,P=0.882）试验组与对照组的差异均没有统计学意义。试验组的临床视诊指数在拆除托槽3个月、6个月与基线比较差异均有统计学意义（P＆lt;0.05）,但第3个月与第6个月的差异没有统计学意义（t=1.860,P=0.083）。结论应用2.26 mg/mL的氟涂料对固定矫治后出现的釉质脱矿进行再矿化治疗后,牙釉质脱矿程度有所降低,但再矿化效果不够显著。     

Effect of bovine lactoferrin on enamel demineralization and acid fermentation by Streptococcus mutans

The purpose of this study was to evaluate the effects of bovine lactoferrin on acid fermentation and enamel demineralization using Streptococcus mutans in a culture system and an artificial mouth model system. The antibacterial activity of bovine lactoferrin (bLF) against S. mutans was analyzed by a radial diffusion assay. In the culture system, the effect of bLF on the synthesis and adherence of water insoluble glucan (WIG) and the adherence of S. mutans to a glass surface was examined by a batch culture. In the artificial mouth model system, cell suspension of S. mutans, heart infusion broth supplemented with sucrose, and PBS or lactoferrin solution were supplied separately and constantly for 21 hours. The following parameters were determined for evaluation: the amount of artificial biofilm, the changes in pH underneath the biofilm; and the changes in enamel microhardness measured by a Vicker's hardness tester. The antibacterial activity of bLF against S. mutans was observed. The amounts of bacterial cells in the total adherent fractions were inhibited by bLF in a dose dependent manner. The amounts of WIG in a firm-adherent fraction were significantly inhibited by 0.1–1.0% bLF. The changes in microhardness on enamel slabs in the bLF group (2.4 ± 0.8) showed significantly less hardness reduction than those in the control group (22.3 ± 2.5) (P < 0.001). The artificial biofilm accumulation was not reduced by bLF. The results of this study suggest that bLF might have inhibitory effects against acid fermentation and demineralization of enamel by S. mutans.     

Influence of fluoride concentration and ethanol pre-treatment on the reduction of the acid susceptibility of enamel

Objective

To determine the association between KOH-soluble and structurally bound fluoride uptake and the erosion resistance of enamel, respectively. Additionally, the effect of enamel pre-treatment with ethanol before fluoridation was assessed.

Methods

Sixty bovine incisors (4 specimens/tooth) were randomly allocated to six groups (A-F). Samples 1 and 2 remained untreated, serving as control at baseline. Pre-treatment of the samples was performed for 5 min with 99% ethanol (groups A, B and C) or physiologic saline (groups D, E and F). Samples 3 and 4 were treated either with 0.5% (groups A and D), 1.0% (groups B and E) or 1.5% (groups C and F) fluoride solution. In samples 1 and 3, uptake of KOH-soluble and structurally bound fluoride was determined. Samples 2 and 4 were used for the determination of acid susceptibility by immersion in 1 ml HCl for 30 s. Calcium release into HCl was assessed by atomic absorption spectroscopy. Differences between the groups were calculated by unpaired t-tests (p < 0.05).

Results

Mode of pre-treatment showed no influence on fluoride acquisition. KOH-soluble and structurally fluoride uptake increased with increasing fluoride concentrations. Highest acid resistance was observed after treatment with 1% fluoride solution for both kinds of pre-treatment followed by 1.5% and 0.5% fluoride solution.

Conclusion

Dose-dependency was observed for enamel fluoride acquisition but not for acid resistance.     

Retention of KOH-soluble fluoride on enamel and dentine under erosive conditions--A comparison of in vitro and in situ results

OBJECTIVES: Aim of the study was to investigate the stability of CaF(2)-like precipitates on enamel and dentine under neutral or acidic conditions and to compare in vitro and in situ results. METHODS: Human enamel and dentine specimens were fluoridated (Elmex fluid, 5 min) and subjected to erosive demineralisation (Sprite light: 3/day each; 30 s in vitro, 2 min in situ) or stored under neutral conditions for 4 (in vitro) or 7 (in situ) days. KOH-soluble fluoride was determined using an ion selective electrode. Between the acid attacks, specimens were stored in remineralisation solution (in vitro) or retained in the oral cavity (four volunteers for enamel and dentine each). RESULTS: Initially, high amounts of KOH-soluble fluoride were gained (between 77.9+/-12.3 and 96.0+/-46.4 microg/cm2). Under neutral conditions in vitro, a significant decrease on enamel (16.2+/-5.0 microg/cm2) and dentine (18.6+/-10.5 microg/cm2) was found, which was more severe under acidic conditions (6.3+/-3.0 and 5.1+/-2.1 microg/cm2, respectively). Under in situ conditions, KOH-soluble fluoride was strikingly stable on enamel under neutral (42.3+/-12.6 microg/cm2) as well as under acidic conditions (54.1+/-17.4 microg/cm2). On dentine, the dissolution kinetics of KOH-soluble fluoride was similar to the in vitro conditions, but the loss was less severe (45.3+/-12.9 microg/cm2 under neutral and 8.8+/-6.4 microg/cm2 under acidic conditions). CONCLUSIONS: In vitro, more KOH-soluble fluoride was lost under erosive compared to neutral conditions. The intra-oral environment was considerably protective for CaF2-like precipitates especially on enamel.     

Effects of CPP-ACP with sodium fluoride on inhibition of bovine enamel demineralization: a quantitative assessment using micro-computed tomography

Objectives

The present study evaluated the effects of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and CPP-ACP with 900 ppm fluoride (CPP-ACPF) pastes on inhibition of enamel demineralization over time, using polychromatic micro-computed tomography (micro-CT).

Methods

Enamel blocks were prepared from bovine teeth. The specimens were each treated by one of the following agents, 30 min daily for 7 days: deionized water (negative control); CPP-ACP paste; CPP-ACPF paste; and NaF solutions (positive controls) (90, 900, and 9000 ppm F). After treatment, the specimens were immersed in a demineralizing solution (pH 4.5) for 24, 72, and 120 h. Mean mineral loss (ML) and lesion depth (LD) after each period were determined from mineral density profiles obtained using micro-CT.

Results

ML values in all the treatment groups were significantly smaller than those in the control group after 72 and 120 h of demineralization (p < 0.05, two-way ANOVA and t-test with Bonferroni correction). ML values in CPP-ACPF and NaF solution groups were significantly smaller compared to CPP-ACP group after 72 h (p < 0.05). LD values in the CPP-ACPF and all the NaF solutions groups were significantly smaller compared to the control group after 120 h (p < 0.05). The 9000 ppm F group showed the lowest nominal ML and LD values.

Conclusions

The application of CPP-ACP or CPP-ACPF pastes to sound enamel surfaces resulted in inhibition of enamel demineralization, and a better effect was noted for the latter paste. Quantitative assessment using polychromatic micro-CT demonstrated to be useful for detecting mineral density changes.     

Effect of added calcium phosphate on enamel remineralization by fluoride in a randomized controlled in situ trial

Dental products containing calcium phosphate and fluoride are claimed to enhance enamel remineralization over fluoride products.

Objectives

To compare remineralization of enamel subsurface lesions by dental products with added calcium phosphate in a double-blind, randomized, cross-over in situ study.

Methods

Human enamel specimens with subsurface lesions were prepared and inserted into intra-oral appliances worn by volunteers. A slurry (1 g product plus 4 ml H₂O) of each product was rinsed for 60 s, 4 times per day for 10 days. Six products were tested (i) placebo, (ii) 1000 ppm F, (iii) 5000 ppm F, (iv) Tooth Mousse (TM), (v) TM plus 900 ppm F (TMP) and (vi) Clinpro with 950 ppm F. Calcium, inorganic phosphate and fluoride levels were measured in post-rinse/saliva samples using ion chromatography. Mineral content was measured using transverse microradiography.

Results

Only TM and TMP significantly increased salivary calcium and phosphate levels. The products produced remineralization in the following order from lowest to highest: placebo < 1000 ppm F = Clinpro < 5000 ppm F < TM < TMP.

Conclusion

Clinpro was not significantly different to 1000 ppm F whereas TM and TMP were superior to 5000 ppm F with TMP producing the highest level of enamel lesion remineralization.     

氟化物在预防正畸釉质脱矿中的应用

釉质脱矿是正畸临床中经常伴有的牙体损害,一旦发生,大部分不可逆转,常会影响到牙齿的健康和美观,因此预防釉质脱矿非常重要.氟化物的应用可以抑制釉质脱矿的发生并促进釉质再矿化.氟化物防龋机制主要是降低釉质溶解度、生成氟化钙和氟磷灰石来促进釉质再矿化.本文就氟化物预防正畸釉质脱矿的可能机制和预防方法进行综述.     

多乐氟在正畸治疗中对牙釉质脱矿的影响

目的：评价多乐氟在正畸固定矫治中对釉质脱矿的预防作用。方法选择接受正畸固定矫治的患者56例,采用自身对照,粘接托槽后,将患者牙齿以中线为界,左侧牙设为试验组（包括21、22、23、24、31、32、33、34）,右侧牙设为对照组（包括11、12、13、14、41、42、43、44）,共观察896颗牙（每组448颗牙）,试验组每3个月在托槽和带环周围牙面涂布多乐氟,对照组不做处理。分别在治疗开始后第6、12个月时对受试牙进行检查,观察牙面釉质脱矿的发生率及脱矿指数。结果正畸开始前试验组和对照组的脱矿率和脱矿程度比较差异均无统计学意义（P＞0.05）;在固定矫治6个月后对照组脱矿率较试验组高,两组间差异无统计学意义（P＞0.05）,但脱矿程度对照组高于试验组;矫治12个月后,对照组的脱矿率和脱矿程度均高于试验组程度（P＜0.05）。结论多乐氟对固定正畸过程中釉质脱矿具有预防作用。     

不同浓度氟泡沫对牙釉质表面显微硬度的影响

目的：观察不同浓度氟泡沫对脱矿牙釉质表面显微硬度值的影响。方法：将牙釉质块随机分为A，B两组，脱矿30min后在两组牙釉质表面分别涂布0．9％中性氟化钠氟泡沫和1．23％酸性氟磷酸盐氟泡沫4min，并在人工唾液中浸泡30min,24h后测定牙釉质表面显微硬度值，结果：两组不同浓度氟泡沫涂布后牙釉质表面显微硬度值均有显著提高，人工唾液浸泡30min和24h，涂布1．23％酸性氟磷酸盐氟泡沫组的牙南表面显微硬度值均高于0．9％中性氟化钠氟泡沫组，统计学检验30min时有显著差异，24h无差异。结论：两种浓度的氟泡沫均可使牙釉质表面显微硬度显著提高，1．23％酸性氟磷酸盐氟泡沫影响效果优于0．9％中性氟化钠氟泡沫。     

In situ de- and remineralisation of enamel in response to sucrose chewing gum with fluoride or non-fluoride dentifrices

Objectives: Enhancement of the remineralisation of artificial enamel lesions has been observed in an intraoral model whether subjects chewed gum sweetened with a non-cariogenic sweetener such as sorbitol [1, 2, 3] or sucrose [4] after meals or snacks, and with use of a conventional (1500 ppm F) fluoride dentifrice. Since most of the clinical surveys which have shown the potential cariogenicity of sucrose chewing gum [5] were conducted before use of fluoridated dentifrices became widespread, the effect of fluoride dentifrice on de- and remineralisation of artificial lesions in enamel in response to chewing sucrose-sweetened gum has been examined with the aim of attempting to resolve this apparent discrepancy. Methods: Subjects wore an intraoral device bearing an enamel lesion and chewed one piece of sucrose gum for 20 min after each of three meals and two snacks daily for two 3-week periods, during which they used a dentifrice containing either 0 or 1500 ppm F in a double-blind, cross-over design. Measurement of the mineral content of the lesions was determined by microradiography or polarised light microscopy. Results: It was found that remineralisation tended to occur with 1500 ppm F dentifrice, but demineralisation with non-F dentifrice; the difference in enamel mineral content between the two periods was significant (P<0.05). Conclusions: The results indicate that the potential cariogenicity of sucrose-containing chewing gum may indeed be negated by the use of a conventional fluoride dentifrice.     

Effect of fluoride containing bleaching agents on enamel surface properties

OBJECTIVES: To evaluate the effects of fluoridated bleaching agents and post-bleaching fluoridation treatment on the whitening efficiency and microhardness of bovine enamel. METHODS: Twenty five freshly extracted bovine incisors were cut into halves, embedded and then divided into the following five groups: Group 1, untreated controls; Group 2, treatment with 10% carbamide peroxide (CP) bleaching agent; Group 3, treatment with 10% CP followed by a 0.9% sodium fluoride gel application, Group 4, treatment with 10% CP containing 0.11% fluoride; Group 5, treatment with an experimental bleaching agent consisting of 10% CP and 0.37% fluoride. Groups 2-5 were treated 8h per day for 14 days then immersed in saliva for 2 weeks. Enamel morphology changes were evaluated under SEM on Day 14. Changes in enamel color and microhardness were evaluated on Days 7 and 14, and compared with the baseline data. Additionally, microhardness was determined on post-bleaching Days 21 and 28. RESULTS: After 2 weeks, an erosion pattern was noted on the specimens in Groups 2 and 3. Groups 4 and 5 showed a milder demineralized pattern. All the bleached enamel specimens revealed increased whiteness and overall color value. Groups 2 and 3 showed significantly decreased enamel microhardness compared to their baseline data. The specimens treated with fluoridated bleaching agents showed relatively less reduction in enamel microhardness than those treated with nonfluoridated agents during the bleaching treatment. CONCLUSIONS: The fluoridated bleaching agents produced less demineralization of surface morphology and microhardness. The addition of fluoride did not impede the whitening effect.