刷牙对酸蚀后釉质表面磨损程度的研究

目的 比较经柠檬酸酸蚀后的釉质块在不同再矿化时间后,刷牙对其表面磨损深度的影响。方法 60个釉质块平均分为A~F共6组,分别安置在10个志愿者的腭基托上。实验第1天,志愿者口腔中佩戴腭基托24 h,其后3 d,每天进行刷牙实验2次。步骤如下：首先,用蜂蜡覆盖F组釉质块,将腭基托置于50 mL柠檬酸溶液中酸蚀2 min,然后取出腭基托,冲洗,并将F组釉质块蜂蜡去除;其他组为酸蚀后经过不同的再矿化时间后刷牙（A组：0 min;B组：20 min;C组：40 min;D组：60 min;E组：酸蚀并且再矿化,但不刷牙;F组：不酸蚀,再矿化,刷牙）。进食及清洁时取出腭基托,其余时间均需佩戴腭基托。通过表面轮廓仪测量釉质块的磨损深度,并用扫描电子显微镜（SEM）观察其表面形貌。结果 酸蚀后经过不同时间的再矿化,刷牙对釉质块表面造成的磨损深度不同,各组间的差异具有统计学意义（P<0.05）。SEM结果显示,釉质酸蚀后再矿化时间越短,刷牙后表面凹陷越大越深越多,表面形态越粗糙。结论 釉质被酸蚀后,在唾液中再矿化时间增加,立即刷牙会对釉质表面形成较大的磨损,60 min后再刷牙可以有效减少刷牙对酸蚀釉质的磨损。     

含氟牙膏对酸蚀后牙釉质的作用

本研究目的是通过扫描电子显微镜的观察来研究含氟牙膏对正畸患者酸蚀后牙釉质表面形态的影响。本实验以因正畸需要而拔除的四个第一前磨牙为研究材料，同一个体的同名牙配对研究。牙冠颊面酸蚀后分别将其浸泡入含氟牙膏浆中和去离子水中。三周后，经含氟牙膏处理的牙釉质表面可见大量沉积物出现，而且釉质表面变得平滑。经去离子水处理的牙釉质表面仍可见到清晰的酸蚀结构。进行人工龋实验后发现，用含氟牙膏处理的牙釉质抗酸性比用去离子水处理牙釉质的抗酸性要强。这说明含氟牙膏能促进酸蚀釉质的再矿化，同时增强其抗酸性。因此应建议正畸患者常规使用含氟牙膏刷牙。     

不同酸蚀条件对釉质表面的影响研究

目的　探究不同pH值的盐酸溶液和酸蚀时间对釉质表面的影响。方法　制作40个釉质片样本，每个样本表面分为未处理面和处理面。根据处理面酸蚀条件分为8组，其中酸蚀时间为30 s，pH值分别为1.6、2.4、3.2、4.0的4组记为A1、A2、A3、A4组；酸蚀时间为60 s，pH值分别为1.6、2.4、3.2、4.0的4组记为B1、B2、B3、B4组。利用显微硬度计测量样本表面显微硬度；激光共聚焦显微镜测量样本未处理面和处理面之间形成的高度差（即釉质丧失量）。对结果进行两因素析因设计资料的方差分析。结果　酸蚀后，A1～A4组样本表面显微硬度值分别下降（42.1 ± 5.8）、（23.6 ± 5.7）、（10.9 ± 6.9）和（-0.6 ± 2.6）MPa；B1～B4组样本表面显微硬度值分别下降（59.3 ± 6.6）、（35.4 ± 9.2）、（15.7 ± 5.1）和（7.7 ± 3.1）MPa。A1～A4组样本未处理面和处理面之间的高度差分别为（793.4 ± 43.0）、（319.2 ± 20.4）、（15.8 ± 2.4）和（-1.4 ± 3.3）nm；B1～B4组样本未处理面和处理面之间的高度差分别为（1366.6 ± 174.8）、（437.2 ± 41.0）、（75.1 ± 6.4）和（1.3 ± 3.2）nm。方差分析结果显示，酸蚀时间和盐酸溶液的pH值对釉质表面显微硬度值下降量及釉质丧失量均有显著影响。结论　酸蚀时间和盐酸溶液的pH值均是影响釉质表面显微硬度值下降量及釉质丧失量的因素，且酸蚀时间和盐酸溶液的pH值对釉质丧失量的影响存在交互作用。     

氟保护漆与含氟自酸蚀粘结剂预防固定正畸治疗早期釉质脱矿的临床研究

目的：对氟保护漆与含氟自酸蚀粘结剂预防固定正畸治疗早期釉质脱矿的临床效果进行对比研究,寻找一种更为有效的氟化物应用方法。方法：随机选择接受固定正畸治疗的青少年患者22名,在每个患者的1区和3区使用含氟自酸蚀粘结剂粘固托槽,在2区与4区常规酸蚀后使用化学固化型京津釉质粘结剂粘固托槽,随后涂布氟保护漆。采用DIAGNOdent激光荧光诊断仪分别对不同区域的牙面釉质脱矿程度进行定量诊断,并在患者1个月、3个月复诊时重复监测。结果：粘结完成即刻与粘结后1个月时,含氟自酸蚀粘结剂使用区（1区、3区）与涂氟保护漆区（2区、4区）之间DIAGNOdent读数均有显著性差异（P〈0.05）,前者读数低于后者。粘结后3个月时,两组间的DIAGNOdent读数无显著性差异。结论：含氟自酸蚀粘结剂降低了正畸托槽粘结时釉质的脱矿程度,在一定程度上有利于减轻正畸治疗早期釉质脱矿的进一步发生、发展。氟保护漆在促进脱矿釉质再矿化方面的作用优于含氟自酸蚀粘结剂。     

不同釉质酸蚀技术对正畸托槽粘接的影响

牙面的酸蚀是影响正畸粘接力的一个重要因素，如何正确选择和使用酸蚀方法一直是研究的热点。本文就酸蚀剂的不同种类、剂型、浓度、酸蚀时间及酸蚀技术对正畸粘接力的影响作一综述。     

不同釉质酸蚀技术对正畸托槽粘接的影响

牙面的酸蚀是影响正畸粘接力的一个重要因素,如何正确选择和使用酸蚀方法一直是研究的热点。本文就酸蚀剂的不同种类、剂型、浓度、酸蚀时间及酸蚀技术对正畸粘接力的影响作一综述。     

含氟牙膏刷牙后唾液游离氟的变化

本研究采用实验对照研究方法,通过各实验组应用含氟牙膏和空白牙膏刷牙,分别在刷牙前和刷牙后1分钟、15分钟、30分钟和60分钟留取混合唾液标本,采用离子选择电极法测定唾液游离氟,观察各组间唾液游离氟的变化差异,分析含氟牙膏刷牙后唾液游离氟的变化规律。结果表明,刷牙后唾液游离氟呈两个阶段规律性变化,无龋组刷牙后唾液游离氟的变化差异无显著性意义。     

义齿内氟化物控释装置对酸蚀釉质再矿化作用的研究

采用自身前后对照的方法研究义齿内氟化物控释装置对酸蚀釉质再矿化的作用。结果表明，应用氟化物控释装置，其释氟率为０．２ｍｇ／ｄ，１周后就可在扫描电镜下观察到典型的再矿化小点，第４周可见到较完整的再矿化，同时，釉质氟含量也显著高于对照组。     

Kr:F准分子激光处理釉质与酸蚀釉质粘结强度的比较性研究

目的 探讨Kr:F准分子激光处理釉质表面后对粘接强度的影响。方法 牙齿釉质面分别经Kr:F激光照射或酸蚀后,与窝沟封闭剂粘接,比较两组的粘接强度。结果 Kr:F激光处理组与酸蚀组粘接强度间无显著性差异(P>0.05)。结论 Kr:F准分子激光替代化学酸蚀法处理釉质表面具临床可行性和独特的优越性。     

含Sn2+/F-牙膏和漱口液对牙齿抗酸蚀性磨损的效果评价

目的:评价单纯和联合使用含Sn2+/F-牙膏和漱口液对牙齿的抗酸蚀性磨损效果.方法:收集智齿85颗,制备牙釉质和牙本质试件各36个.以3个釉质和3个本质为一组,制作一个腭基托.选取12名受试者分成4组佩戴(n=3),每日定时用1％柠檬酸浸泡4次,5 min/次.在首次和末次浸泡后口腔维护,A组:不含牙膏刷牙(对照)、B...     

A study in vitro of the combined effects of soft drinks and tooth brushing with fluoride toothpaste on the wear of dentine

The aim of this study was to measure loss of dentine produced by soft drinks alone and combined with tooth brushing with and without toothpastes. Groups of flat human dentine specimens were exposed for 10 min and then 30 min to orange juice (OJ), carbonated cola (CC) or modified blackcurrant (MB) drinks alone or after the exposures brushed with a fluoride toothpaste for 10 s. Further groups were exposed to OJ as before but brushed with water or non-fluoride toothpaste or placed in slurries of fluoride paste. Five cycles of each regimen were carried out. Tissue loss was determined by profilometry. Water immersion/brushing and brushing controls were included. OJ and CC produced similar erosion and significantly more than MB. Compared with drinks alone, dentine loss was reduced by fluoride toothpaste brushing but increased by water and non-fluoride toothpaste brushing. Fluoride toothpaste slurry had no significant effect on soft drink erosion. Very little abrasion with brushing alone was recorded over the time frame of these experiments. It is concluded that fluoride toothpaste could provide protection, albeit small, against erosion. The data again support the concept of brushing before meals.     

局部应用氟化物对酸蚀釉质作用的体外研究

目的：评价局部应用氟化物对酸蚀釉质的作用。方法：收集正畸减数拔除的年轻前磨牙40个，制备釉质样本，随机分成对照组，lg／L氟化钠液组，含氟牙膏组，联合应用组。用饮料对釉质间断性酸蚀1周，然后使用不同的氟化物处理酸蚀的釉质表面1周。采用显微硬度计检测釉质表面显微硬度值（SMH），原子力显微镜（AFM）、扫描电镜（SEM）观察牙体硬组织表面的结构。结果：饮料浸泡后釉质的SMH明显下降。与对照组相比，氟化物处理后各氟化物处理组的釉质SMH均有明显增加（P＜0．001）。AFM和SEM均可见酸蚀后的釉质表面呈典型的蜂窝状结构，SEM观察显示氟化物处理后，各组釉质表面均有一定沉积物。结论：饮料会导致体外釉质表面的脱矿，氟化物能够促进体外酸蚀釉质的再矿化。     

The protective effect of fluoride treatments against enamel erosion in vitro

Fluoride is known to reduce enamel solubility during the caries process. The aim of this investigation was to determine whether fluoride preparations affect erosion attributed to citric acid and citric acid-based soft drinks. Flat enamel specimens embedded in epoxy resin were prepared from caries free, human third molar teeth extracted from patients aged 18-35 years. Specimens were polished to have a profile within a tolerance of +/-0.3 microm measured on a profilometer. Specimens were taped to leave a 2 mm window of exposed enamel. Groups of specimens were exposed to citric acid and soft drinks with and without the addition of sodium fluoride or exposed to the same solutions after pre-treatment with fluoride products. Enamel loss was measured by profilometer after 10, 20 and 30 min of acid exposure. The different acidic solutions varied significantly in the amount of erosion produced both with and without the addition of fluoride. In addition, the different fluoride products differed significantly in the protective effect afforded. Both fluoride application methods reduced in mean terms, enamel erosion at all time points and by all acidic solutions. The majority of differences were <25% and as the study was powered to show differences as significant at or above this level few reached statistical significance. Fluoride applied to enamel either in acidic solutions or as a pre-treatment, reduces enamel erosion; however, the actual clinical benefit appears low. More studies are required, including investigations in situ.     

In vitro enamel fluoride uptake from topical fluoride agents

The F acquired by enamel from APF, Duraphat and Fluor Protector was evaluated in this in vitro study. The topical F agents were applied to the tooth surfaces for 4 min, the teeth were suspended in synthetic saliva and the topical F agents removed after 2 h or 4 h. The teeth were resuspended in synthetic saliva for 1, 3 and 6 months, respectively. Three successive enamel biopsies were done on the control and experimental tooth halves and the F and P content of the etching solutions determined. The fluoride concentrations were adjusted to standardized depths of 3.0, 6.0 and 9.0 μm, respectively. Enamel acquired significantly more F from Fluor Protector and Duraphat than from APF. The fluoride acquired by enamel from the topical F agents was inversely related to the enamel F concentration prior to topical F application.     

Toothbrush abrasion, simulated tongue friction and attrition of eroded bovine enamel in vitro

OBJECTIVES: Enamel erosion results in the formation of a softened layer that is susceptible to disruption by mechanical factors such as brushing abrasion, tongue friction and attrition. The aim of this study was to investigate the individual contribution of those mechanical insults to the enamel loss caused by dental erosion. METHODS: Forty two bovine enamel samples were randomly divided into seven groups (n=6 per group) that were submitted to 3cycles of one of the following regimes: erosion and remineralization (er/remin); toothbrush abrasion and remineralization (abr/remin); erosion, toothbrush abrasion and remineralization (er/abr/remin); attrition and remineralization (at/remin); erosion, attrition and remineralization (er/at/remin); simulated tongue friction and remineralization (tg/remin); erosion, simulated tongue friction and remineralization (er/tg/remin). Erosion took place in a demineralization solution (50mM citric acid, pH 3) for 10min under agitation. Brushing abrasion, tongue friction and attrition were simulated for 1min using a home-made wear device. Remineralization was carried out in artificial saliva for 2h. Enamel loss was quantified using optical profilometry. RESULTS: One-way ANOVA indicated a significant difference between the amounts of enamel lost due to the different wear regimes (p相似文献   

Enhanced enamel benefits from a novel fluoride toothpaste

Objectives : Through the understanding of tooth enamel science and insights into the beneficial role calcium can play in the caries process, a novel fluoride toothpaste has been developed containing micro‐calcium. This paper describes a series of in vitro studies to assess delivery of the micro‐calcium to a plaque biofilm, delivery of radiolabelled micro‐calcium to subsurface enamel lesions and the rehardening of acid softened enamel by this novel toothpaste. Two clinical studies evaluated the delivery of calcium to the mouth. Methods : Uptake of micro‐calcium to a plaque biofilm was assessed using a Calgary Biofilm Device and measuring the calcium levels delivered to the biofilm from the micro‐calcium containing toothpaste, a calcium carbonate toothpaste, a silica toothpaste or water controls. Sound and subsurface enamel lesions were treated with ⁴⁵Ca labelled micro‐calcium toothpaste in an in vitro pH cycling study and the uptake of labelled calcium determined. Acid softened enamel specimens were treated with either the micro‐calcium containing toothpaste, a calcium carbonate toothpaste or a non‐fluoride silica toothpaste in an in vitro remineralisation protocol and the changes in surface microhardness measured. Calcium delivery in vivo was determined in two double‐blind, randomised cross‐over studies. Subjects brushed their teeth for one minute with either the micro‐calcium containing toothpaste or a silica toothpaste. Immediately after brushing and at fixed time intervals up to one hour, unstimulated saliva samples were taken and the total calcium concentration determined. Results : Significantly (p<0.05) more calcium was delivered to a plaque biofilm from the micro‐calcium containing toothpaste than the controls. The radiolabelled micro‐calcium study demonstrated the uptake of calcium to subsurface enamel lesions. In the remineralisation study, acid softened enamel became significantly harder (p<0.05) following treatment with the micro‐calcium containing toothpaste than compared to the control toothpastes. It was shown in the two clinical studies that more calcium was delivered to the mouth following the use of the micro‐calcium containing toothpaste than compared to the silica toothpaste. The product differences were in excess of 50% and were of statistical significance (p<0.001). Conclusions : The studies show that the new toothpaste containing micro‐calcium delivered elevated levels of calcium to the mouth, promoted enhanced remineralisation of demineralised enamel lesions and thus can help repair early signs of tooth decay.