釉质龋的非破坏性治疗方法

釉质龋是一种非细胞反应性病变,可导致牙齿硬组织的破坏。传统治疗釉质龋的方法往往会损害到正常的牙体组织,因此目前非破坏性修复釉质龋的新方法成为了研究的热点和难点,本文就非破坏性治疗釉质龋的2种方法——再矿化和仿生矿化法的最新进展作一综述。     

矿化液对釉质表层下脱矿的再矿化实验研究

目的　评价矿化液对釉质表层下脱矿的再矿化效果。方法　通过人工龋方法获得不同程度的釉质表层下脱矿病损。然后每天用矿化液处理釉质脱矿病损 1小时 ,共 6 0天。应用显微X线仪检测釉质脱矿病损区域矿物质含量变化。结果　对于轻度的釉质脱矿病损 (2 4小时人工龋 ) ,应用矿化液后获得良好的再矿化效果。表现在病损矿物质丧失量降低和病损深度变浅 ,最低矿物质含量升高和表层厚度的增加。对于程度较重的釉质脱矿病损 (4 8小时人工龋 ) ,应用矿化液后也出现了再矿化现象。表现在矿物质丧失量的减少和最低矿物质含量的升高 ,但病损体部深度没有明显改变。结论　正畸治疗中应用矿化液也许是一种良好的治疗措施。     

釉质表层特征与早期釉质龋形成的关系

釉质表层是在早期龋时釉质表面相对完整的一层结构，其出现与表面釉质的晶体排列和化学组成有关，早期釉质龋不单是矿物质的溶解和丢失，还包括溶解的矿物质在釉质表层的选择性再矿化，釉质表层和再矿化在早期龋损过程中有重要作用。对釉质表层和早期釉的研究是指导早期龋预防和治疗的关键。本文就釉质表层结构特点，化学组成特点及近6年来众学者对早期龋的形成和预防方面的研究作一综述。     

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     

早期釉质龋表层形成的化学机理

典型的牙釉质龋损均有一脱矿程度较深层组织轻的表层,再矿化可能是该表层形成最主要的化学机理,正常釉质表层固有的结构特点和特殊理化性质也起一定作用。研究早期釉质龋损表层形成的化学机理不仅是了解龋病发生动力学的重要内容,而且为临床防龋和治疗早期龋提供理论依据。     

早期釉质龋表层形成的化学机理

典型的牙釉质龋损均有一脱矿程度较深层组织轻的表层，再矿化可能是该表层形成最主要的比学机理，正常釉质表层固有的结构特点和特殊理化性质也起一定作用。研究早期釉质龋损表层形成的化学机理不仅是了解龋病发生动力学的重要内容，而且为临床防龋和治疗早期龋提供理论依据。     

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.     

微量元素矿化液再矿化效果的体内研究

目的　选择体外实验证实具有较强的促进釉质早期龋再矿化作用的微量元素矿化液 ,评价其在体内的脱矿及再矿化效果。方法　制备含 2mm× 2mm正常和人工龋釉质块的可摘口内装置 ,将其置于受试者口内 ,采用激光共聚焦技术观察罗丹明B荧光染料渗透进入多孔釉质荧光量的多少 ,量化受试者在使用不同矿化液前后的再矿化效果 ,用ΔZa、ΔZb 及ΔZ(Zb 与ΔZa 的差值 )来表示 ,具体包括测釉质块荧光量的面积 (Areaofthefluorescentlesion ,A)、总的荧光量 (totalfluorescence ,TF)及病损的平均荧光量 (averagefluorescent,AF) 3个共聚焦参数。结果　受试者口内装置经含氟矿化液和微量元素矿化液处理后脱矿釉质块的共聚焦参数ΔZa 与处理前的ΔZb 相比差异有显著性 (P <0 0 5) ,尤以微量元素组明显。其激光共聚焦结果为 ,ΔZ :A =(- 50 4± 8 1 ) μm2 ,TF =- 2 7 8± 3 8,AF =- 91 5± 8 9,说明微量元素矿化液在体内仍能获得比单纯含氟矿化液更好的促进早期龋再矿化的效果。结论　微量元素矿化液有完善现有含氟矿化液防治早期龋的潜力 ,为临床的进一步应用奠定基础 ,为脱矿和再矿化研究提供了新方法     

3种无氟儿童牙膏对乳牙早期釉质龋再矿化作用的体外研究

目的 探究3种市售无氟儿童牙膏即生物活性玻璃儿童牙膏、双黄连儿童牙膏、木糖醇儿童牙膏对乳牙早期釉质龋的再矿化作用。方法 应用离体乳牙制备人工龋模型50例,随机分为5组：活性玻璃组、双黄连组、木糖醇组、NaF组、去离子水组。在体外进行pH循环后,测量各组乳牙的表面显微硬度,并结合偏光显微镜对乳牙的釉质龋损进行形态学观察。结果 活性玻璃组能显著提高乳牙早期釉质龋再矿化后的表面显微硬度（P<0.05）,但其提高的程度不如NaF组（P<0.05）,双黄连组、木糖醇组和去离子水组未能提高再矿化后的显微硬度（P<0.05）。偏光显微镜下,活性玻璃组与NaF组再矿化后乳牙表层釉质的脱矿深度明显变浅。结论 生物活性玻璃儿童牙膏能有效促进乳牙早期釉质龋再矿化,但其再矿化能力小于含氟牙膏,双黄连儿童牙膏和木糖醇儿童牙膏在本次实验中未能体现出再矿化能力。     

钙磷再矿化及其系统

龋病是一种釉质脱矿与再矿化作用失衡,牙体硬组织向脱矿方向持续发展的疾病。当口腔内钙和磷酸根离子饱和度下降时,釉质脱矿;反之,釉质再矿化;因此,钙和磷酸根离子是再矿化的物质基础,钙磷离子浓度越高,越有利于釉质再矿化的发生。无定形钙磷（ACP）能与氟离子结合生成无定形钙磷氟（ACPF）,ACP和ACPF能向口腔环境提供可利用的钙磷和氟离子,促进釉质的再矿化;但亦降低可利用的钙、磷酸根和氟离子浓度,降低其促再矿化能力。酪蛋白磷酸肽（CPP）与钙和磷酸根以一种微弱的化学力结合,使得CPP-ACP复合体中的钙、磷酸根离子与口腔环境中的游离钙、磷酸根离子间保持一种动态平衡。当pH值较高时,大量钙、磷离子以CPP-ACP形式存在;随着pH值降低,CPP-ACP释放出钙、磷酸根离子促进釉质再矿化。CPP-ACP有效定位于龋损表层及表层下并释放钙和磷酸根离子,具有良好的促再矿化效果。氟具有良好的再矿化防龋效果,可通过与CPP-ACP中的氢氧根离子置换生成CPP-ACPF。CPP-ACPF通过附着于牙体表面或顺CPP-ACPF浓度梯度渗透进入釉质龋坏表层下,持续释放钙、磷酸根和氟离子,促进釉质表层和表层下再矿化。     

Validation of swept source optical coherence tomography (SS-OCT) for the diagnosis of smooth surface caries in vitro

ObjectiveAn accurate evaluation of the extent of dental caries and possible progress of the lesion from enamel into dentin is very important in clinical dentistry. Dentists need an imaging technology that can noninvasively and reliably quantify the extent of caries. This study aimed to evaluate the effectiveness of non-polarized swept source optical coherence tomography (OCT) in evaluating the extent of caries on smooth enamel surfaces.MethodsOne-hundred and twenty-seven investigation sites on the enamel surfaces of 93 extracted teeth were selected randomly and examined visually. The presence and extent of caries were scored by experienced and inexperienced dentists using each observation method (0: no caries; 1: enamel demineralization without surface breakdown; 2: enamel breakdown due to caries; 3: deep caries involving the dentin). The same locations were then examined using OCT, following which the teeth were sectioned using a diamond saw and viewed directly under a confocal laser scanning microscope (CLSM). Sensitivity and specificity indices for OCT and VI were calculated and compared. The results were analysed statistically using receiver operating characteristic (ROC) curves.ResultsEnamel and dentin caries were outlined by a visible boundary on the cross-sectional OCT images. The modality showed superior results for the detection of dentinal caries; higher sensitivity and Az values could be obtained in the ROC curves, especially by experienced dentists.ConclusionsCross-sectional imaging of the natural caries lesions on smooth enamel surface by OCT enables efficient diagnosis of the lesion type, extent and dentin involvement.Clinical significanceSS-OCT can demonstrate the cross-sectional image of smooth surface enamel caries as highlighted zone in tomogram. It is crucial to determine the extent of the lesion, whether it reaches beyond DEJ or not by a non-invasive and safe technique. OCT can give clinicians information about internal tooth structure and will help clinical decision making on surgical intervention.     

ICON渗透树脂修复人工釉质龋白斑的效果研究

目的：评价ICON渗透树脂修复人工釉质龋白斑的效果。方法：选取因正畸而拔除的前磨牙28颗,制备人工釉质龋后,随机分为实验组和对照组,实验组采用ICON渗透树脂修复人工釉质龋白斑,对照组采用涂氟处理,测量并比较釉质龋白斑修复后的表面微硬度和龋白斑面积减少百分比,最后采用SPSS17．0软件进行统计分析。结果：治疗修复后实验组釉质龋的表面微硬度值显著高于对照组,差异具有统计学意义（P＜0．05）;修复后实验组龋白斑所占面积百分比低于对照组,差异具有统计学意义（P＜0．05）。结论：ICON渗透树脂能提高人工釉质龋白斑表面的微硬度,并能大大降低龋白斑的面积百分比,推荐临床使用。     

牙釉质蛋白质在龋进展中的作用

本文通过牙釉质的发育过程阐述了釉质蛋白质在龋进展中发挥作用的生物学基础；并通过近年来的研究文献从牙釉质蛋白质对早期釉质龋脱矿的影响及蛋白水解酶与釉质龋的关系两方面综述了釉质蛋白质在龋发生中的作用。     

Invasion of bacteria in enamel carious lesions

A review of recent findings concerning enamel carious lesions is presented. This lesion represents the initial phase of dental caries and is characterized by a demineralization of the subsurface enamel caused by acids of the plaque bacteria. Streptococcus mutans has been described as the etiologic agent of the dental caries and the most acidogenic plaque bacteria. Morphological studies have shown an invasion of microorganisms inside the enamel carious lesion. Unfortunately, several technical problems are associated with such studies. The identification of the invading bacteria has not yet been achieved. The future identification of bacteria inside the subsurface enamel lesions will represent an important step in the prevention of the carious progression.     

Enamel roughness and incidence of caries after interproximal enamel reduction: a systematic review

The aim of this study was to investigate the effect of interproximal enamel reduction (IER) on tooth surfaces regarding the level of enamel roughness after applying different IER methods and the caries risk of treated teeth. Seven electronic databases were systematically searched. Two independent reviewers rated the articles at every step according to predetermined eligibility criteria. Data on enamel roughness were pooled if the same IER method was used and arithmetic values were available. Data on occurrence of caries were suitable for the analysis if the same units for caries development were used. From 2396 citations initially identified, 18 articles met the inclusion criteria and were further considered (14 studying enamel roughness and four studying the risk of caries after IER). A meta‐analysis of quantitative data regarding enamel roughness was not possible due to statistical heterogeneity; instead, the enamel roughness findings are only described. The meta‐analysis of studies focusing on the incidence of caries revealed no statistical difference between treated and untreated enamel surfaces (p = NS) from 1 to 7 years after IER. Drawing reliable conclusions on enamel roughness after IER is difficult owing to the diversity of the available studies. Statistically, the occurrence of caries on surfaces previously treated with IER was the same as that on intact surfaces, indicating that IER does not increase the risk of caries on treated teeth.     

Inherited risks for susceptibility to dental caries.

Dental caries incidence is affected by host factors that may be related to the structure of dental enamel, immunologic response to cariogenic bacteria, or the composition of saliva. Genetic variation of the host factors may contribute to increased risks for dental caries. This systematic review examined the literature to address the question, "Is the risk for dental decay related to patterns of genetic inheritance?" Numerous reports have described a potential genetic contribution to the risk for dental caries. Studies on twins have provided strong evidence for the role of inheritance. Establishing a basis for a genetic contribution to dental caries will provide a foundation for future studies utilizing the human genome sequence to improve understanding of the disease process. Inherited disorders of tooth development with altered enamel structure increase the incidence of dental caries. Specific genetic linkage has not been determined for all of the syndromes of altered tooth development. Consequently, genetic screens of large populations for genes or mutations associated with increased caries susceptibility have not been done. Altered immune response to the cariogenic bacteria may also increase the incidence of caries. Association between specific patterns of HLA genetic inheritance and dental caries risk is weak and does not provide a predictable basis for predicting future decay rates. The evidence supporting an inherited susceptibility to dental caries is limited. Genetic linkage approaches on well-characterized populations with clearly defined dental caries incidence will be required to further analyze the relationship between inheritance and dental caries.     

Hexahedrally based crystals in human tooth enamel.

Mg-containing calcium phosphate crystals including pseudocuboidal, rhombohedral shapes and groupings of quadrangular blades cubically arranged were found in human tooth enamel by scanning electron microscopy and by electron probe microanalysis. In caries-free old enamel, these hexahedrally based crystals measuring 0.5-2.5 microns in length were observed in some crevices of tufts and lamellae. The crystals were rarely seen in the inner crevices of caries-free exfoliated deciduous enamel and none could be seen in sound young enamel. In brown-coloured old enamel possessing arrested caries with lamellae, some of the lamellae contained crystals measuring 0.1-1.5 mu in length adjacent to half-dissolved prisms. These crystals, identified as Mg-containing whitlockite, will grow during a long period after eruption of the tooth or during the enamel caries process.     

绿茶多酚涂膜与牙体粘附性能的实验研究

目的 观察绿茶多酚涂膜在牙面上的粘附时间，以评价绿茶多酚涂膜的防龋效果。方法 将32颗离体牙的He面涂布绿茶多酚涂膜，放在37℃恒温水浴内，选16个不同时间进行涂膜粘附情况的观察。结果 用绿茶多酚涂膜涂布的32个离体牙在192h之内涂膜未见脱落，288h之后涂膜大部分脱落。结论 绿茶多酚涂膜与牙齿表面能够稳定的粘附，滞留时间较长，有利于绿茶多酚的释放，起到防龋作用。     

Hidden occlusal caries lesion--a diagnostic challenge

In the 1980s a new type of caries lesion was added to the lexicon of Dentistry, namely, the Hidden Caries. The hidden caries is a sub-type of the occlusal pit and fissure caries type, and is defined as a dentinal caries lesion nearby the occlusal surface of the tooth, seen on a radiograph, where the occlusal enamel remains intact or is minimally perforated. The cariogenic bacteria penetrate into the enamel via a minimal hole in the enamel surface, but once reaching the softer dentine, their progression is less restricted, and meanwhile the fluoridated enamel undergoes remineralization thus covers the traces. Hidden caries lesions challenge the dental surgeon in diagnosis, treatment planning and research, in particular because of their 'hidden' nature. The potential diagnostic errors regarding hidden caries are undiagnosing, false-positive diagnosing, and misdiagnosing. The article reviews and demonstrates the differential diagnosis of a radiolucent spot on the occlusal dentin layer in posterior bitewing radiograph.