牙本质龋损下牙本质-牙髓复合体的反应

目的 探讨牙本质龋损进展过程中,牙本质-牙髓复合体的变化特点及规律.方法 选择即刻拔除的第三磨牙65颗,其中牙本质浅龋27颗(急性龋15颗,慢性龋12颗);牙本质深龋28颗(急性龋16颗,慢性龋12颗);无龋损的正常牙10颗.常规固定、脱钙、切片(厚4 μm),光学显微镜下观察牙本质龋病损下方牙髓的组织病理学改变,并用多功能图象分析仪对相应部位的成牙本质细胞的数目、浆核比、前期牙本质面积等进行测量分析.结果 随龋损深度的增加,成牙本质细胞数目显著减少,细胞形态由高柱状变为立方状直至扁平状,前期牙本质变薄甚至消失,第三期牙本质变厚且发生率增加,血管扩张充血,炎症细胞增多,主要为淋巴细胞与浆细胞;牙本质浅龋阶段,成牙本质细胞浆核比显著下降,慢性龋成牙本质细胞样细胞分化、迁移活跃,胶原纤维增多.牙本质深龋阶段出现修复性牙本质,急性龋炎症细胞聚集明显.结论 牙本质-牙髓复合体对龋损的反应与龋损深度及活动性有关;龋损深度增加,损伤反应加重;龋损活动性降低时修复与防御反应加强.     

牙髓-牙本质复合体

牙髓-牙本质复合体的各结构组分相互依赖、相互影响、相互作用,构成一个功能性的有机整体.本文就牙髓-牙本质复合体的概念、动力学特性、体外培养及临床应用等方面作一综述.     

牙髓—牙本质复合体

牙髓－牙本质复合体的各结构组合相依赖、相互影响、相互作用,构成一个功能性的有机整体,本文就牙髓－牙本质复合体的概念、动力学特性、体外培养及临床应用等方面作一综述。     

关于"牙本质-牙髓复合体"一词的译名

由于牙本质和牙髓在胚胎学、组织学和功能上有极为密切的关系,所以近几十年来常将二者称为复合体。在英美一些教科书或专著上有:dentino- pulp complex,dentin- pulp complex,pulp- dentin complex,pulpodentin complex等名词,因而在我国书刊上也就出现“牙本质-牙髓复合体”、“牙髓-牙本质复合体”,甚至还有“牙髓牙本质器官”等等。鉴于与其他专业名词一致,例如“enamo-dentin junction”,“dentiono- enamal junction”译为“釉牙本质界”,而不译为“牙本质釉质界”,我们推荐将dentin- palp complex译为“牙本质-牙髓复合体”,不用“牙…     

牙髓组织损伤修复的机制

牙髓组织具有修复潜能,其损伤修复机制目前尚不搞清楚。本文从细胞学和分子学水平对牙髓损修复的机理进行了回顾。     

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。     

牙髓干细胞与牙本质再生相关性的研究进展

牙髓中存在具备自我更新和多向分化潜能的牙髓干细胞。这些细胞经诱导可向成牙本质细胞分化并形成牙本质样结构，有望成为牙本质再生的种子细胞。本文就牙髓干细胞的来源、生物学特性及其在牙本质再生中的应用作一综述。     

牙髓组织损伤修复的机制

牙髓组织具有修复潜能,其损伤修复机制目前尚不搞清楚。本文从细胞学和分子学水平对牙髓损伤修复的机理进行了回顾。     

特异性鸡蛋黄抗体对人工釉质龋形成的影响

目的：研究特异性鸡蛋黄抗体（IgY）对人工釉质龋形成的影响。方法：采用人工菌斑模型研究IgY对早期釉质龋形成的影响。56块釉质块经唾液包被后置6种与菌斑形成有关的混合细菌液中培养。实验组釉质块每两天置IgY液中浸泡处理,在实验第7、14、21、28、35天分别取出对照、实验组釉质块,磨片后偏光显微镜下观察,并采用显微X线照相系统投照,TMR软件分析早期釉质脱矿量、龋损的深度。结果：对照组较实验组更早出现釉质龋,实验组釉质脱矿量为1275．2 vol％um,显著低于对照组2836．5vol％ um。结论：特异性IgY在体外能有效减缓早期釉质龋的发生。     

Characteristics of dental enamel and its resistance to caries

Systematical research of basic texture characteristics (specific surface area, specific volume and size of micro-, meso- and macropores, porosity) of intact dental enamel of persons with various degree of resistance to caries has been performed using methods of adsorption and Hg-porosimetry. Studied objects have been shown to be small-porous (total porosity epsilon = 4-6%), roughly-dispersed (specific surface S6ET = 0.7-1.5 m2/g) materials. Regularities of changes of specific surface and porous structure in researched samples have been established. More mesoporous enamel structure has been shown to form in the series of samples varying from high level of resistance to very low level. Meanwhile intact dental enamel has the same degree of macroporosity irrespective of the level of its resistance to caries. Micropores within the samples have been established to be heterogenous and their volume to be very insignificant (2-4 x 10(-9) m3/g). Substantiation of various degree of resistance of intact dental enamel to carious process has been suggested within the framework of structurally-geometrical approach.     

Pulp response to Streptococcus mutans

The maxillary molar pulps of germ-free rats were mechanically exposed, and suspensions of a strain of freshly grown Streptococcus mutans were applied to the pulp wounds. The pulps were left open to the oral environment, and the animals were maintained in the isolator until they were killed in groups after 2, 7, and 28 days. After 2 days there was little evidence of any pulp response. In the 7-day group early pulp necrosis was present. No evidence of inflammatory infiltration was detected in either the 2- or 7-day animals. After 28 days there was extensive pulp necrosis in many specimens. Dentine bridges were present in fewer than one fourth of the teeth.     

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.     

Proteolytic phenomenon in enamel caries]

The proteolytic phenomenon in enamel caries has been investigated from three directions.Three kinds of proteolytic enzymes,papain,trypsin and collagenase have been used for treating enamel both in vitro and in vivo to observe their effect on the development of artificial enamel caries and demineralization of upper central incisors of thirty young persons.The results showed that the depth of the artificial caries was not increased after enzyme treatment.The calcium content of the demineralizing solution is also not increased after enzyme treatment.when the enamel powder of human beings was treated at first by natural plaque fluid and then by demineralizing liquid,no difference was observed between the data of experimental and control groups.Therefore,the results of this study does not support Gottleib's proteolytid theory of caries,especially in case of enamel ones.