暨南大学口腔组织病理学牙本质ppt.ppt

Chapter 3 Dentin 主 讲 沈 丽 佳 Pulp-dentinal complex----Dentine I. Physical and Chemical properties II. Histological structure III. Innervation IV. Biological properties V. Clinical consideration Discussion I. Physical and chemical properties Distribution of dentine Physical properties Chemical properties Comparative anatomy I. Physical and chemical properties 与骨的相似之处 与骨的不同之处 Physical properties of dentine 牙本质呈浅黄色,具有一定的弹性。 牙本质硬度平均68 KHN。 牙本质还具有丝绢状光泽，由于有牙本质小管存在，具有较高的透射度与通透性。 Chemical properties of dentine: The non-mineral component is much higher than in enamel The principal inorganic component is hydroxyapatite, the crystals are smaller than those of enamel The main organic component is type I collagen with proteoglycans (dentin sialophosphoproteins, dentin matrix protein 1, glycosaminoglycans )between the fibers. Chemical properties of dentine: 无机物为羟基磷灰石晶体，但比釉质内的晶体小，还有少量磷酸盐、碳酸盐和硫酸盐。此外还有一些微量元素如：氟、铜、锌、铁。 有机成分中，胶原蛋白主要是I型胶原（约占18%)及牙本质基质蛋白、胺基多糖等。 II. Histological structure Regional differentiation of dentine: Mantle dentin (crown) Hyaline layer (root) Circumpulpal dentin Predentin II. Histological structure 1. Dentinal tubules 2. Odontoblastic processes 3. Peritubular dentin 4. Intertubular dentin 5. Incremental lines 6. Globular dentin and interglobular dentin 7. Tomes granular layer 1. Dentinal tubulesSummary: General condition of the dentinal tubules: 牙本质小管 髓 腔 端 釉 质 端 数目 30,000—7,500条/mm2 1,500条/mm2 管径 3—4 μm 1 μm 分支小管 较少 1μm 较多 1 μm ?形弯曲 突面朝向牙根 突面朝向牙冠 管壁厚度 400 nm 750 nm 2. Odontoblastic processes （1）光镜结构： （2）电镜结构： 在胞浆突起内，胞浆较少，细胞器也较少，主要为微管（Microtubules）、微丝 （filaments）、线粒体 （