Study on the mechanism of idiopathic calcification in hard tissue of tooth

牙齿硬组织特发性钙化机制的研究

• 批准号: 07672004
• 负责人: TANIGUCHI Kunihisa
• 金额: $ 1.47万
• 依托单位: Fukuoka Dental College
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07672004/
• 关键词: tooth germ; trauma; enamel hypoplasia; hypocalicification; irregular dentin; ankylosis; disturbance of eruption; 歯胚の外傷; エナメル質形成傷害; 石灰化不全

This study was designed to inbestigate the mechanism of the defects of hard tissue formtion by traumatic injury to tooth term, to examine on the relationship between the timing of trauma and the defects of hard tissue formation after trauma. We gave experimental traum by penetration to tooth germs at different developmental stages, and examined traumatic changes and the degree of disturbance. Taruma before matrix formation of enamel (postnatal 1 day) produced localized defects of amelogenesis and we obserbed the defect of enamel locally with a SEM image. Irregular dentin was fromed and normal dentin formation was grandually repaired. In trauma at the early stage of enamel matrix fomation (postnatal 3 days), the defects of amelopeneses and irregular dentine formation with the formed hard tissue before ftauma occurred. In SEM findings, morphological change occurred in the cuspid and enamel hypoplasia was observed partially. Trauma at satge of enamel matrix formation (postnatal 5,7 days) … More affected the plural cuspids and the defects of hard tissue formation occurred at the tooth cervix. The surface of enamel wasrough with SEM image. At the same time, the crown of tooth germ was displaced or ankylosis at the cervix with the disturbance of eruption was seen. It was speculated that the canses for the appearance of these tooth cervix were due to be subjected to load of strees by trauma at the stage of matrix formation. Odontblasts were partly detached from dentin. Irregular dentin with cellular inclusions were distributed and dentin formed after trauma showed thickeing. Trauma at the stage of calcification induced a slight injury of hard tissue, but showed the defects of hard tissue formation at the tooth cervix in many cases. It was seemed that trauma at the same stage induced hypocalcification because enamel matrix remained partly.It's suggested that the degree and location of defects of hard tissue formation were different degending on the timing of trauma to the tooth germ. Less

本研究旨在探讨外伤性牙体硬组织缺损形成的机制，探讨外伤时间与外伤后硬组织缺损形成的关系。对不同发育阶段的牙胚进行实验性穿剌损伤，观察损伤后的变化及损伤程度。在釉质基质形成前（出生后1天）的Taruma产生了局部的釉质形成缺陷，我们用扫描电镜图像对釉质缺陷进行了局部观察。不规则牙本质形成，正常牙本质形成逐渐修复。在釉质基质形成的早期（出生后3天），创伤后牙釉质缺损，牙本质不规则形成，并伴有创伤前形成的硬组织。扫描电镜下可见尖牙形态改变，部分牙釉质发育不全。釉质基质形成阶段的创伤（出生后5、7天） ...更多信息 影响多个尖牙，牙颈部硬组织形成缺损。扫描电镜观察釉质表面粗糙。同时牙胚牙冠移位或牙颈部强直，萌出障碍。据推测，这些牙颈的出现是由于在基质形成阶段受到创伤应力的负荷。成牙本质细胞部分脱离牙本质。不规则牙本质内有细胞内含物分布，创伤后形成的牙本质增厚。钙化期的外伤对牙颈部硬组织损伤轻微，但多表现为牙颈部硬组织缺损。同一时期的牙胚外伤，由于釉质基质的部分残留，导致牙胚钙化不足，提示牙胚硬组织缺损的程度和部位随牙胚外伤时间的不同而不同。少