全光纤OCT量化检出早期釉质龋的研究

目的评价全光纤光学相干断层成像（全光纤OCT）检出早期牙釉质人工龋的敏感性。方法在新鲜拔除的7颗离体人恒牙釉质光滑面制备2mm×3mm实验窗．选用pH4．5的化学酸蚀液在开窗区制备0～120h早期脱矿人工龋模型．采用自行研发的口腔全光纤OCT系统检测离体人恒牙早期牙釉质人工龋,以同一牙齿样本的显微数码摄影和偏光显微镜检测作为对照．比较和检验OCT有效检出早期龋变的敏感性和可行性。结果全光纤口腔OCT装置可早期准确检测到脱矿12h以内牙釉质表面组织学水平的微观改变,早于裸眼和临床显微摄影的观察结果：开窗区釉质表面完整度随脱矿作用时间出现递减变化;而釉质脱矿深度随脱矿作用时间而出现递增性变化,不同时段脱矿深度的OCT量化数据与偏光显微镜检出结果相吻合．统计学分析结果表明2者间无显著性差异（P〉0．05）,证实OCT可早期、敏感、精确地检出组织学水平的早期牙釉质人工龋。结论全光纤口腔OCT系统可无创准确检出早期牙釉质表面和表层下人工龋变．获得的龋变深度量化测量数据与偏光显微镜下组织学水平的测量结果高度相关。系统进一步完善后有望作为一种新型光学手段用于口腔临床龋病的早期诊断、量化监控以及干预效果的有效评估。     

生物活性玻璃对早期人工釉质龋的再矿化

背景：生物活性玻璃具有良好的生物相容性,且具有抑制口腔致龋细菌和牙周相关细菌及抗牙本质过敏的作用。 目的：评价生物活性玻璃促进早期人工釉质龋再矿化的作用。 方法：将新鲜拔除的30颗牛切牙制成人工龋模型,将标本在37 ℃人工脱矿液内脱矿72 h,用扫描电镜观察脱矿后釉质表面的平滑情况,用显微硬度仪测量脱矿后釉质的显微硬度。然后随机分为3组,每组10个。采用pH循环法模拟人口腔环境,将3组标本分别浸泡在生物活性玻璃溶液、氟化钠溶液及人工唾液内,3次/d,10 min/次,循环浸泡20 d,扫描电镜检测标本脱矿及再矿化情况,用显微硬度计检查牙釉质显微硬度。 结果与结论：浸泡在生物活性玻璃溶液中的牙釉质表面较浸泡在其他两溶液中的牙釉质表面光滑平整,无空隙存在;浸泡在生物活性玻璃溶液中的牙釉质表面显微硬度高于浸泡在其他两溶液中的牙釉质表面显微硬度(P < 0.05)。说明生物活性玻璃在体外实验中能促进早期釉质龋的再矿化。     

基于光学相干断层成像量化评估平滑面早期牙釉质龋的研究进展

背景：平滑面早期牙釉质龋虽然已发生脱矿改变但无肉眼可见的龋洞形成,目前临床采用的常规检测方法难以对其准确诊断。 目的：应用光学相干断层成像技术对平滑面早期牙釉质龋的量化研究进展进行综述。 方法：由第一作者检索CNKI和EBSCO HOST数据库中1979/2011发表的关于光学相干断层成像技术定量研究平滑面早期龋的相关文献,以“光学相干断层成像,早期龋,平滑面,量化评估”和“optical coherence tomography, early caries, smooth surface,quantitative assessment”为检索词进行检索。纳入31篇进行综述。 结果与结论：新兴的光学相干断层成像技术能够检测龋变牙釉质的背向散射信号使脱矿牙釉质成像,并应用深度、反射率、衰减系数等定量指标对平滑面早期牙釉质龋进行量化评估,为牙釉质早期龋的诊断提供了新的方法。     

基于聚集诱导发光的多肽荧光探针的制备及其在早期龋齿检测中的应用

目的:制备基于聚集诱导发光的多肽荧光探针,并对其在早期龋齿检测中的应用进行探讨。方法:将8个天冬氨酸-丝氨酸-丝氨酸(DSS)与聚集诱导发光材料结合制备多肽荧光探针,体外建立人工脱矿模型,将样本浸泡于多肽荧光探针溶液中1 min,应用荧光成像系统对牙齿样本进行检测并收集图像和荧光数据。同时应用扫描电镜观察牙齿的表型,电子显微镜检测牙齿釉质表面钙磷比,偏光显微镜观察牙齿釉质区域。结果:多肽荧光探针处理区域明显可以观察到脱矿牙齿的荧光强度低于正常牙齿,且差异有统计学意义( P<0.05)。扫描电镜显示脱矿组的牙釉质表面可见较多不规则孔隙;未脱矿组的牙釉质表面较为表面平坦,可见一些不规则的片状物堆积。偏振光显微镜结果显示正常牙齿的釉质区域可以观察到明显的双折射,而脱矿牙齿的釉质区域可以观察到一道黑色区域,或是双折射效应消失,可见部分黑色暗影。 结论:制备了一种基于聚集诱导发光的多肽荧光探针,其能够精准定位牙釉质,在早期龋齿检测中具有一定的应用价值。     

含氟纳米氟磷灰石糊剂修复人工釉质缺损

背景：纳米氟磷灰石糊剂涂敷法可在人牙齿表面生长出类似牙釉质的柱状晶体。 目的：观察1 mg/L人体安全浓度的氟离子对纳米氟磷灰石糊剂修复人工釉质缺损的影响。 方法：将人工早期釉质缺损样本随机分成两组,分别在样本表面涂敷添加含氟的纳米氟磷灰石糊剂(实验组)与不加氟的纳米氟磷灰石糊剂(对照组),置于37 ℃水浴孵箱中修复。反应前后对牙齿表面行扫描电镜观察,晶体结构分析,化学成分鉴定和韦氏显微硬度测试。 结果与结论：经处理后,两组样品表面都可见有一层与牙釉质化学组成和晶体结构类似的晶体生成,但实验组牙釉质样品表面结晶度、韦氏显微硬度明显高于对照组样品(P < 0.05),且实验组牙釉质样品表面更光滑。结果表明,人体安全浓度含氟纳米氟磷灰石糊剂可明显提高人工釉质龋显微硬度、结晶度和表面光滑度。     

纳米羟基磷灰石封闭牙本质小管的效果

背景：纳米羟基磷灰石是优良的生物活性材料,对脱矿牙釉质和牙本质具有一定的保护作用,但其溶液对脱矿牙本质再矿化的作用及其机制尚不明确。目的：探讨纳米羟基磷灰石用于防治牙本质敏感症和牙本质龋的可行性。方法：收集废弃的人双尖牙标本,制备出72份牙本质薄片,分6组处理：A组脱矿后浸入10%纳米羟基磷灰石溶液中,B组脱矿后浸入6%生物活性玻璃溶液中,C组脱矿后浸入10%纳米羟基磷灰石与6%生物活性玻璃复合溶液中,D组脱矿后浸入0.05%NaF溶液中,E组脱矿后浸入人工唾液中,F组脱矿后浸入去离子水中,每组12个样本。处理14 d后,扫描电镜下观察样本工作面,利用能谱分析仪检测样本表面成分,激光共聚焦显微镜下检测牙本质罗丹明B染色情况。结果与结论：(1)扫描电镜观察：A组牙本质小管口被完全封闭,牙本质表面被一层紧密连接的颗粒物均匀覆盖;C组牙本质小管部分封闭;B、D、E组牙本质表面及牙本质小管内见少量散在颗粒物,牙本质小管口呈开放状;F组牙本质表面及牙本质小管内未见颗粒物沉积,牙本质小管口呈开放状态;(2)X射线能谱分析：A组Ca/P比为1.61,最接近健康牙本质理论值,Ca/P比高于B、E、F组...     

口腔光学相干计算机断层摄影术

光学相干计算机断层摄影术（optical coherence tomography，OCT），是近10年间迅速发展起来的一种新的生物组织成像技术。文章介绍口腔OCT原理和主要功能，阐述口腔OCT在离体口腔组织断层成像、在体口腔组织的实时断层摄影、龋损牙体组织的早期诊断、牙体修复和窝沟封闭效果的评估、监控龋病发展进程、口腔黏膜疾病的无创诊断、口腔软组织癌前病变的无创早期诊断中的实际应用，并与其他影像设备诊断进行比较，展望OCT的发展。     

新教学模式下组织学实验考核权重与内涵变革的探索

<正>组织学实验教学手段在不断的更新、改建,由过去的单一显微镜教学,到多媒体大屏幕投影辅助教学,再到眼下的数码显微互动教学[1],可以说新技术革命引领组织学实验教学进入了一个新的时代。我院形态学实验室于2012年建立了第一个显微数码互动实验室,将计算机、信息网络技术引入了组织学显微镜实验室,显微数码互动技术凸显出其明显的教学优势,丰富的数字切片资源也为组织学的实     

早期自然釉质龋光学相干断层图像定量分析

目的 通过对早期自然龋变光学相干断层成像(OCT)图像进行定量分析,寻找适于光学相干断层成像技术检测早期龋的定量参数指标.方法 选取D0期、D1期和D2期自然发生釉质龋双尖牙标本各3颗,利用光学相干断层成像分别对上述不同程度早期釉质龋人离体牙进行扫描,并以龋变区域(目标区域)平均灰度值与正常区域(背景区域)平均灰度之比...     

掺钕钇铝钙钛晶体激光结合两种再矿化制剂与早期釉质龋的再矿化

背景：近年来，多种激光被广泛应用于口腔医学相关的各种疾病，包括龋病的预防及治疗。目的：探讨掺钕铝酸钇晶体(neodymium-doped:yttrium aluminum perovskite,Nd:YAP)激光联合两种再矿化制剂对早期釉质龋再矿化的作用。方法：将60颗牙釉质块体外建立人工龋模型后，随机分为6组(n=10):A组不进行任何处理，行体外pH循环；B组进行护牙素(主要成分为酪蛋白磷酸钙复合体)再矿化处理，行体外pH循环；C组进行舒适达牙膏(主要成分为生物活性玻璃)再矿化处理，行体外pH循环；D组进行Nd:YAP激光照射，行体外pH循环；E组进行Nd:YAP激光照射，然后进行护牙素再矿化处理，行体外pH循环；F组进行Nd:YAP激光照射，然后舒适达牙膏再矿化处理，行体外pH循环；再矿化处理2次/d，实验周期20 d。G组为正常对照，未致龋，未进行再矿化处理，仅行体外p H循环。实验结束后，检测各组牙釉质表面的显微硬度、形貌与Ca/P比值。结果与结论：(1)B、C、D组牙釉质表面的硬度值高于A组(P <0.000 1),E、F组牙釉质表面的硬度值明显高于B、C、D组(P ...     

Ex vivo detection and characterization of early dental caries by optical coherence tomography and Raman spectroscopy

Early dental caries detection will facilitate implementation of nonsurgical methods for arresting caries progression and promoting tooth remineralization. We present a method that combines optical coherence tomography (OCT) and Raman spectroscopy to provide morphological information and biochemical specificity for detecting and characterizing incipient carious lesions found in extracted human teeth. OCT imaging of tooth samples demonstrated increased light backscattering intensity at sites of carious lesions as compared to the sound enamel. The observed lesion depth on an OCT image was approximately 290 microm matching those previously documented for incipient caries. Using Raman microspectroscopy and fiber-optic-based Raman spectroscopy to characterize the caries further, spectral changes were observed in PO4 (3-) vibrations arising from hydroxyapatite of mineralized tooth tissue. Examination of various ratios of PO4 (3-) nu2, nu3, nu4 vibrations against the nu1 vibration showed consistent increases in carious lesions compared to sound enamel. The changes were attributed to demineralization-induced alterations of enamel crystallite morphology and/or orientation. OCT imaging is useful for screening carious sites and determining lesion depth, with Raman spectroscopy providing biochemical confirmation of caries. The combination has potential for development into a new fiber-optic diagnostic tool enabling dentists to identify early caries lesions with greater sensitivity and specificity.     

Remineralization of in vitro dental caries assessed with polarization-sensitive optical coherence tomography

Polarization-sensitive optical coherence tomography (PS-OCT) is potentially useful for imaging the nonsurgical remineralization of dental enamel. This study uses an all-fiber-based PS-OCT system operating at 1310 nm to image demineralized and fluoride-enhanced remineralized artificial lesions. PS-OCT images of lesions before and after remineralization are compared with the relative mineral loss DeltaZ (%vol x microm), obtained from high resolution digital microradiography (DM), and chemical composition changes by infrared spectroscopy. Severe early artificial caries show a significant increase in perpendicular-axis integrated reflectivity after remineralization. After sectioning the samples, DM demonstrates that the lesions remineralized with new mineral and the lesion surface zone show significant restoration of mineral volume. PS-OCT and DM both do not show a major change in lesion depth. For less severe artificial caries, the perpendicular-axis image resolves the scattering and depolarization of an outer growth layer after remineralization. This outer layer has a mineral volume close to that of sound enamel, and spectroscopic analysis indicates that the layer is a highly crystalline phase of apatite, without carbonate substitutions that increase the solubility of sound enamel. This study determines that PS-OCT can image the effects of fluoride-enhanced remineralization of mild and severe early artificial in vitro caries.     

BODIPY光敏药物在牙齿美白上的应用研究

目的探讨氟化硼络合二吡咯甲川（BODIPY）光敏药物结合光动力治疗（PDT）在牙齿美白的应用及对牙齿表面釉质的影响。方法人离体牙分别经过氧化氢和BODIPY光敏药物光动力美白处理后,使用vita比色板和扫描电镜观察,分析不同方法对牙齿的美白效果及美白前后牙齿表层釉质在晶体和丑微结构上发生的改变。结果经过美自处理前后进行对比,过氧化氢法美白效果显著,但牙齿表面釉质出现严重脱矿现象;BODIPY光敏药物PDT法的美白效果良好,牙齿光滑,牙齿表面有再矿化现象。结论利用BODIPY光敏药物的PDT法对牙齿具有一定的美白效果,并能促进牙齿表面釉质的再矿化,有望成为牙齿美白的新方法。     

Automatic quantitative analysis of ore content of human tooth enamel based on image processing

Introducing the theory of fuzzy set, mathematical morphology and computerized mask fast scanning, we developed the TOOTH.SCA software and method to analyze the effect of fluoride (NaF) on ore content of human tooth enamel automatically and quantitatively. And we obtained some characteristic parameters, such as the depth, the type and the demineralized content of every scathing layer of dental caries. The smallest scale of mask scanning is 0.1 microm x 0.1 microm and the time required to analyze a sample is only 12 s. The applied software and method we built play an important role to the research on the mechanism of pathological changes of teeth and preventing dental caries.     

Quantitative light-induced fluorescence: a potential tool for general dental assessment

Current dental diagnostic methods can detect caries but cannot quantify the mineral status of a lesion. Quantitative light-induced fluorescence (QLF) measures the percentage of fluorescence change of demineralized enamel with respect to surrounding sound enamel, and relates it directly to the amount of mineral lost during demineralization. Development of caries-like lesions and subsequent remineralization of the lesions were monitored by QLF. The results showed that the percentage of fluorescence change (Delta Q) increased linearly with the demineralization time and decreased with increased remineralization time. Stained teeth were whitened with a bleaching agent and the change in stain intensity (Delta E) was quantified using QLF. The results showed that Delta E decreased linearly as the tooth regained its natural color. Factors that might affect the use of QLF to detect and quantify caries were also examined. It was concluded that QLF could be used to detect and longitudinally monitor the progression or remineralization of incipient caries, however lesion detection may be limited by the presence of saliva or plaque and enhanced by staining. The change in shade of discolored teeth by whitening agents could be quantitatively measured by QLF.     

Quantitative evaluation of the kinetics of human enamel simulated caries using photothermal radiometry and modulated luminescence

Photothermal radiometry and modulated luminescence (PTR-LUM) is an emerging nondestructive methodology applied toward the characterization and quantification of dental caries. We evaluate the efficacy of PTR-LUM in vitro to detect, monitor, and quantify human enamel caries. Artificial caries are created in extracted human molars (n = 15) using an acidified gel system (pH 4.5) for 10 or 40 days. PTR-LUM frequency scans (1 Hz-1 kHz) are performed before and during demineralization. Transverse microradiography (TMR) analysis, the current gold standard, follows at treatment conclusion to determine the mineral loss and depth of the artificially demineralized lesions. A theoretical model is applied to PTR experimental data to evaluate the changes in optothermophysical properties of demineralized enamel as a function of time. Higher optical scattering coefficients and poorer thermophysical properties are characteristic of the growing demineralized lesions, as verified by TMR, where the generated microporosities of the subsurface lesion confine the thermal-wave centroid. Enhanced optical scattering coefficients of demineralized lesions result in poorer luminescence yield due to scattering of both incident and converted luminescent photons. PTR-LUM sensitivity to changes in tooth mineralization coupled with opto-thermophysical property extraction illustrates the technique's potential for nondestructive quantification of enamel caries.     

利用光学相干断层图像平均灰度值定量研究牛恒牙早期人工脱矿

目的 研究经酸蚀脱矿后牛恒牙光学相干断层图像平均灰度值的变化,探讨平均灰度值作为一个参数指标定量检测牛恒牙早期脱矿的可行性.方法 以正常离体牛恒牙为样本,采用凝胶酸蚀法制备人工脱矿模型;用光学相干断层摄影术对人工脱矿模型扫描成像,利用Matlab软件计算不同酸蚀时间脱矿区牙体层110 μm范围内的平均灰度值.将测得图像灰度和归一化后图像灰度,分别进行单因素方差分析.结果 牙体表层110 μm范围内不同时间酸蚀脱矿区的平均灰度值从大到小依次为30 min酸蚀脱矿区、1O min酸蚀脱矿区、0 min酸蚀脱矿区,图像灰度归一化后做单因素方差分析,P＜0.05.结论 牙体表层110 μm范围内不同酸蚀时间脱矿区平均灰度值差异有统计学意义,并随脱矿时间增加而增大,即平均灰度值可以用于光学相干断层摄影术定量检测牙齿的早期脱矿.光学相干断层图像灰度归一化使得不同酸蚀脱矿区的平均灰度值更有可比性,减小了由于样本之间差异引起的误差,提高了平均灰度值作为参数指标定量检测牙齿早期脱矿的可靠性.