受压前颌上颌骨缝组织细胞微观结构变化的观察

目的 :在建立模拟临床双侧上颌前部裂及上颌前颌骨加压的定量研究实验动物模的基础上 ,探索受压骨缝组织的微观结构变化的规律。方法 :12只 3周龄雌性新西兰大耳白兔 ,随机均分为 3组 :空白对照组 ;实验Ⅰ组 ,前颌后推加较小力 ;实验Ⅱ组 ,前颌后推加较大力。分别在术后 3、6、9、12周处死动物 ,取受压迫的前颌上颌骨缝标本 ,切片用于光镜和电镜观察。结果 :在骨缝生长发育的过程中 ,骨缝受一定程度压力后其成骨层的成骨细胞出现损伤 ,并与受力大小成正比。结论 :发育早期骨缝受压会导致该部成骨细胞出现延滞性损伤 ,在一定范围内骨缝基本结构及生长潜力不易被广泛破坏     

Prostaglandin E2 receptor of rat submandibular salivary glands.

The binding characteristics of the PGE2 receptor were investigated in membrane preparations from these glands. Specific [3H]PGE2 binding was linear as a function of the membrane protein concentration and reached steady state by 40 min of incubation at 37 degrees C under neutral pH. Scatchard analysis of the binding data produced a curvilinear plot with a Kd of 0.18 nM and Bmax of 1.02 fmol/mg protein for the high-affinity binding sites, and a Kd of 181 nM and Bmax of 5.72 pmol/mg protein for the low-affinity binding sites. A competitive displacement study indicated that the receptor was specific for prostaglandins of the E series. The study is the first to demonstrate the presence of the PGE2 receptor in rat submandibular gland and to provide its biochemical features.     

牙色度分析在原位乳牙脱矿与再矿化检测中的应用

目的:验证数码照相牙色度分析法进行体内乳牙脱矿与再矿化研究的可行性。方法:选取58例平均年龄为4岁的儿童,以左上中切牙为实验牙,先染色、数码拍照,然后对实验牙面进行酸蚀、染色、数码拍照,最后在口腔环境内自然再矿化24h和1周后再染色、拍照,运用图像分析软件进行牙色度R、G、B值分析,比较酸蚀脱矿及再矿化前后牙色度的变化。用SPSS 19.0软件包对数据进行方差分析。结果:酸蚀脱矿后及再矿化24h后的色值(R、G、B)与基值有显著差异(P<0.05);在1周时间点上,只有B值与基值有显著差异(P<0.05);再矿化24h及1周后,牙色度值与酸蚀后相比有显著差异。结论:数码牙色度分析法可识别乳牙脱矿及再矿化前后牙色度的变化,可用于原位乳牙脱矿与再矿化研究。     

Surface alteration of human tooth enamel subjected to acidic and neutral 30% hydrogen peroxide

Objectives

To investigate the effects of acidic and neutral 30% hydrogen peroxide (HP) on human tooth enamel in terms of chemical structure, mechanical property, surface morphology and tooth colour.

Methods

Twenty-seven human dental blocks were obtained from premolars and randomly divided into three groups (n = 9): Group acidic HP (30% HP, pH ≈ 3.6), Group neutral HP (30% HP, pH ≈ 7.0) and Group DW (distilled water, pH ≈ 6.8). Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, atomic force microscopy (AFM) investigation, microhardness test and colour measurements were carried out before and after treatments. ATR-FTIR and Raman spectroscopy were analysed and then the carbonate:mineral ratio (C:M), Raman absolute intensity (RAI), Raman relative intensity (RRI), and laser-induced fluorescence intensity (FI) were obtained for evaluation.

Results

The C:M, percentage microhardness and percentage RRI of group acidic HP decreased more significantly than those of group neutral HP (P = 0.02, P = 0.001, P < 0.001, respectively) and group DW (P = 0.01, P = 0.008, P < 0.001, respectively). Whilst group neutral HP and group DW had no statistical difference in above terms (P = 0.818, P = 0.528, P = 0.158, respectively). Significant morphological alterations were observed in group acidic HP. Group acidic HP and neutral HP had no significant difference in percentage FI (P = 0.652) and ΔE (P = 0.906).

Conclusions

This study suggested that neutral 30% HP had the same efficiency in tooth bleaching and it caused less deleterious effects on enamel than acidic 30% HP.     

明朝金属全冠及其粘接剂之成分分析

目的考察我国明朝（公元１３６８～１６４４年）的口腔修复技术，并为我国口腔医学史提供一些细节资料。方法借助目测及扫描电镜能谱分析，对江苏武进博物馆编号为０７５４／００４６的二颗馆藏明朝人类牙齿冠部的金属全冠及其粘接剂作了初步成分分析。结果考古分析表明，二牙系明朝嘉靖至万历年间（公元１５００～１６００年）遗物，均为上前牙且无牙体制备痕迹，金属全冠系锤造后焊接而成。能谱分析显示二金属冠分别含金７９３３％及８５８６％，含铜２０６７％及１４１４％，粘接剂内含锌元素。结论我国明朝已能利用高硬度铜金合金及粘接材料修复牙体缺损，表明我国明朝已有较成熟的口腔修复技术。     

应用超声波非破坏性拆除固定修复体

随着人们对口腔美学要求的提高，烤瓷技术的应用越来越广，但烤瓷修复体的损坏，以及修复后基牙出现牙髓炎或根尖周炎的治疗，已成为临床医生颇感棘手的问题。按过去切割等破坏性拆除的方法，往往损坏修复体或使修复体变形，不仅增加病人的就诊次数，也增加了病人经济上的负担。本文利用超声技术对36例固定修复体作非破坏性拆除。取得较满意的效果。报道如下。材料和方法1研究对象选择1995～1996年由口腔修复科转至口腔内科病人共36人，男15人，女21人，年龄24～61岁。其中单冠13例，连冠3例，3个单位固定桥11例，3个位以上的固定桥9例。粘…     

用傅立叶变换红外光谱仪研究复合树脂的双键转化度

为了研究牙科复合树脂的聚合，采用傅立叶变换红外（Ｆｏｕｒｉｅｒｔｒａｎｓｆｏｒｍｉｎｆｒａｒｅｄ，ＦＴＩＲ）光谱仪测定８种牙科复合树脂的双键转化度并比较了压片制样法和薄膜制样法对转化度的影响。结果发现，树脂的双键转化度在４５％～７４％之间；可见光固化树脂的转化度高于化学固化树脂者。在光固化树脂中，混合填料树脂的转化度高于超微填料树脂者，粘接辅助剂的转化度最高。对光固化树脂而言，压片制样法所测得的转化度值高于用薄膜制样法；而在化学固化树脂，用二种制样方法所测得的转化度值相同。本研究结果可供临床应用复合树脂参考。     

A study of bond strength between light- and self-cured orthodontic resin.

Light-cured orthodontic composite resin has been widely advertised recently for use in bonding. However, the curability of light-cured resin when light waves are diffused through metal, ceramic, or resin brackets is doubtful and questionable. This study evaluated the effectiveness of a visible light source in curing the resin under a solid metal bracket, compared the tensile bond strength at different exposures, and analyzed the broken interface distribution between light-cured resin with various light exposure times and self-cured resin. The bond strength results revealed that the difference between light-cured resin (Transbond) with 60, 40, and 20 seconds of light exposure, respectively, and self-cured resin (Concise) was 1.05, 0.92, 0.61, and 0.71 kg/mm2, respectively. The bond strength of Transbond with 60 and 40 seconds of light exposure was greater than both the bond strength of Transbond with 20 seconds of light exposure and the strength of the self-cured resin of Concise, with statistical significance (p less than 0.01). There were also no statistical differences between Transbond with 60 and 40 seconds of light exposure or Transbond with 20 seconds of light exposure and Concise. The bond failure interfaces were located between the bracket and the resin, within the resin itself, or between the resin and the enamel. Tooth fragmentation was rarely found. There were no statistical differences (p greater than 0.05) among broken interfaces. This indicates that visible light is powerful in curing the visible light-activated composite resin under solid metal brackets.(ABSTRACT TRUNCATED AT 250 WORDS)     

Metastases to lingual lymph nodes from squamous cell carcinoma of the tongue

The diagnosis of squamous cell carcinoma (SCC) of the tongue metastasising to the lingual lymph nodes is rare. Until now lingual lymph nodes have not been mentioned in any system of lymph node classification. We report a case of SCC of the tongue with metastases to the lymph nodes in the superficial floor of the mouth, and to levels I and II lymph nodes. We provide evidence of the existence of lingual lymph nodes, and validate the practice of removing the lymph node-bearing-tissue of the floor of the mouth during neck dissection in cancers of the oral cavity.