Management of potentially malignant disorders: evidence and critique

At a workshop coordinated by the WHO Collaborating Centre of Oral Cancer and Precancer in the United Kingdom, issues related to management of patients affected by oral leukoplakia were discussed by an expert group. The consensus views of the working group are presented here. Although removal of a lesion still seems to be the predominant method of treatment by the majority of relevant health care professionals, no randomized controlled trials have been undertaken to test the hypothesis that excision either by scalpel or laser greatly influences the potential for later malignant transformation within the oral mucosa of an affected individual. Results of observational studies indicate that, although surgery may have a beneficial effect, this is not likely to reduce the risk of later recurrence nor malignant transformation at the same or another site. Medical measures that lessen the size, extent or histopathological features of dysplasia within leukoplakia likewise presently do not seem to be of particular promise, as relapse or later malignant transformation can occur, and there is a risk of adverse effects, particularly with systemic agents (which themselves may be contra-indicated in some individuals). While the risk of malignant transformation, and the development of further potentially malignant disease may theoretically be reduced by cessation of risk activities, such as tobacco usage and alcohol consumption, there remain no good studies that demonstrate that such measures significantly reduce such events.     

五倍子对感染根管内厌氧菌抑制作用的体外研究

目的:观察中药五倍子对感染根管内几种常见优势专性厌氧菌和兼性厌氧菌的抑菌作用。方法:采用试管二倍稀释法,测定五倍子水提取物在体外环境下对厌氧消化链球菌、内氏放线菌、具核梭杆菌、中间普雷沃菌、金黄色葡萄球菌、大肠杆菌的最小抑菌浓度(MIC)和杀菌浓度(MBC),同时以氢氧化钙做对照。结果:五倍子对各种试验菌株均有抑制作用,对不同的菌株,MIC和MBC值不同,而氢氧化钙对内氏放线菌、金黄色葡萄球菌、大肠杆菌在试验浓度范围内无抑制作用。结论:五倍子水提取物抗菌效果较好且广泛,用于根管内封药具有一定的应用前景。     

口腔鳞癌手术后中药治疗远期疗效观察

作者曾对２３８例口腔鳞癌术后应用中药“参阳”方的疗效进行前瞻性的研究,本文继续对已生存４～８年的５６例病员门诊随访结果进行分析．结果是生存情况：７年生存期原治疗组高于原对照组１２．５％,原治疗组３０例均健在,而原对照组中的２６例,２例带瘤生存,１例死亡;Ｔ细胞亚群测定中,复发死亡者的ＣＤ８值均升高,ＣＤ４／ＣＤ８比值均下降;中医辨证中,正常者及肾气虚者的例数以治疗组为多,而阴虚与气阴两虚者,治疗组低于对照组;由上提示：经“参阳”方治疗者有较好的远期疗效．     

Ex vivo biocompatibility tests of regular and white forms of mineral trioxide aggregate

AIM: To examine the genotoxicity and cytotoxicity of regular and white mineral trioxide aggregate (MTA) ex vivo by the single-cell gel (comet) assay and trypan blue exclusion test, respectively. METHODOLOGY: Aliquots of 1 x 10(4) Chinese hamster ovary cells were incubated at 37 degrees C for 3 h with grey and white forms of MTA at final concentrations ranging from 1 to 1,000 microg mL(-1). The negative control group was treated with vehicle control phosphate buffer solution for 3 h at 37 degrees C and the positive control group was treated with methyl metasulfonate (at 1 microg mL(-1)) for 1 h at 37 degrees C. After incubation, the cells were centrifuged at 180 g for 5 min and washed twice with fresh medium and resuspended with fresh medium. Each individual treatment was repeated three times consecutively to ensure reproducibility. Parameters from single-cell gel (comet) and cytotoxicity assays were assessed by the Kruskal-Wallis nonparametric test. RESULTS: Neither compounds produced genotoxic effects with respect to the single-cell gel (comet) assay in all concentrations evaluated. In the same way, the dose-response relationships of all compounds tested at concentrations ranging from 1 to 1,000 microg mL(-1) on cell viability assessed by the trypan blue assay displayed no statistically significant differences (P > 0.05) for either endodontic material. CONCLUSIONS: Regular (grey) and white MTA are not genotoxins and do not induce cellular death.     

Bacterial and yeast flora of root surface caries in elderly,ethnic Chinese

OBJECTIVES: Root caries is emerging as a significant problem in the middle aged and elderly. As little data is available on the microbiology of root caries in Chinese cohorts, we evaluated 30 such lesions in elderly, institutionalized, ethnic Chinese. METHODS: Samples of carious dentine were aseptically taken from root caries lesions of 18 subjects (five males and 13 females, mean age 79.67 +/- 8.57). The cultivable bacteria, both aerobic and anaerobic, were isolated and identified using standard methods and commercial identification kits. The yeasts were isolated on Sabouraud's agar and identified using the API system. RESULTS: The main findings were: (1) of the total isolates, 91.09% were Gram-positive and 8.91% were Gram-negative microorganisms; (2) the proportions of cocci and rods were 36.68 and 63.31%, respectively; (3) the predominant groups of organisms isolated were Streptococcus spp., Lactobacillus spp., Staphylococcus spp. and Actinomyces spp. with isolation frequencies of 100, 90.00, 73.33 and 63.33%, respectively; (4) the isolation frequency of yeasts belonging to Candida spp. (63.33%) was notably high although the proportion of yeasts within each sample was low (0.01%). Candida dubliniensis, a newly identified yeast species particularly prevalent in HIV infection, comprised 14.29% of yeasts. CONCLUSIONS: This study provides baseline information on the microbiologic features of root caries in the elderly, ethnic Chinese. Whilst our data on the most predominant bacteria isolated in root caries concur with those from other regions of the world the isolation of C. dubliniensis from these lesions has not been documented before.     

国内复发性口腔溃疡治疗的循证医学分析

目的 分析国内近5年复发性口腔溃疡药物治疗的疗效情况及研究质量。方法 检索中国期刊网全文数据库和中国生物医学数据库，收集发表时间在1999-2003年治疗复发性口腔溃疡疗效观察的中文文献，对符合标准的文献进行META分析和循证医学分析。结果 共检索到281篇文章，符合纳入标准的有18篇，治疗方法共13种，对其中的3篇进行META分析，证明碱性成纤维细胞生长因子治疗组与口服维生索B、C对照组具有显著差异，其95％的可信区间为0．432-0．656。结论 1999-2003年期间国内治疗复发性口腔溃疡的论著数量较多，但高质量研究较少，本研究显示碱性成纤维细胞生长因子局部喷雾剂在缓解疼痛和促进愈合方面疗效确切，值得临床推广使用。     

五倍子对釉质抗酸蚀作用的实验研究

目的：观察中药五倍子对釉质抗酸蚀作用的效果。方法：采用500g/L五倍子水浸剂为实验组，去离子水为阴性对照，20g／L氟化钠为阳性对照，对60个正常离体牙釉质表面进行处理，制备人工龋模型，用硬组织切片机制备100μm原切片，通过显微放射照射系统观察测量五倍子对釉质的抗酸蚀作用效果。结果：500g／L五倍子水浸剂组较去离子水对照组脱矿少（P〈0．05），与20g／L氟化钠对照组相比无显著差异（P〉0．05）。结论：500g／L五倍子水浸剂可明显增强釉质抗酸蚀能力，其效果与20g／L氟化钠相当。     

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。     

人体微生物组在辅助2型糖尿病诊疗中的潜在应用

人体微生物组是指人体体表及内部的微生物的遗传信息总和,与人类健康与疾病状态存在密切关系。口腔和肠道微生物是最具多样化的微生物群落,两者可以交互影响,在疾病发生发展过程中共同发挥作用,并可以实时反映机体的健康与疾病状态。2型糖尿病是由遗传和环境因素引起的代谢紊乱,最近的研究指出微生物与糖尿病存在关联。本文结合近期的研究进展,就2型糖尿病患者口腔微生物和肠道微生物的特征进行综述,有望为探索基于微生物组特征的2型糖尿病风险预测、诊断和预后预测的疾病模型的建立提供参考依据。