Vital Pulpotomy in Young Permanent Monkey Teeth with Open Apices

幼猴恒牙开放性牙髓切开术

基本信息

批准号：
61570916
负责人：
IGARASHI Masaru
金额：
$ 1.09万
依托单位：
The Nippon Dental University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1988
项目状态：
已结题

项目摘要

The vital undeveloped permanent monkey teeth were prepared for pulpotomy with calcium hydroxide. The initial dentinal bridging during a postoperative healing process was examined at 0,6,9,12,24hr.,2,3,4 and 7days after operation by means of light and electron microscope.Sfter immediately dressing an amputated pulp with Ca(OH)_2, the calcium hydroxide produced a necrotic layer extending to 0.5-0.88mm apically from the amputation site. The ealist changes consisted of loss of cellular detail, engorged blood vessels and frequent small haemorrhages. But, the affected arears later did not appear to extend. After 6 hours, a few of deeply eosinophilic small spherical bodies could be seen in and immediately over the superficial pulp necrotic tissue. After 9 hours, in the necrotic zones of clotted blood and pulp there were similar bodies. Ultrastructurally a number of globular clusters and electron dense granules were observed in the deep layer of clotted blood. The organic matrices in the globular clusters apppeared to be composed of fine needle-like shaped crystals and electron dense granules were also observed within the degenerated cells. Thereafter, gathered togather developing to the gross granules, and finally formed irregulary shaped masses. At 7 days, collagen fibrous dentin matrix mixed with cellular elements was formed by odontoblast-like cells.In conclusin, the results of this study suggested that a zone of clotted blood, degenerated cells and cell fragments had some important role in initial dentinal bridging after pulpotomy.

将重要的未发育恒猴牙用氢氧化钙准备用于活髓切断术。术后0、6、9、12、24小时、2、3、4和7天通过光镜和电镜检查术后愈合过程中的初始牙本质桥接情况。立即用Ca(OH)包扎断牙)_2，氢氧化钙产生坏死层，从截肢部位向顶部延伸0.5-0.88mm。实际的变化包括细胞细节的丢失、血管充血和频繁的小出血。但后来受影响的地区似乎并没有扩大。 6小时后，浅表牙髓坏死组织内及紧邻其上可见少量深嗜酸性小球体。 9小时后，在凝固的血液和牙髓的坏死区中出现了类似的尸体。超微结构观察在凝血深层观察到许多球状簇和电子致密颗粒。球状簇中的有机基质似乎由细针状晶体组成，并且在退化细胞内还观察到电子致密颗粒。此后，聚集在一起发展成粗颗粒，最后形成不规则形状的团块。 7天时，成牙本质细胞样细胞形成与细胞成分混合的胶原纤维牙本质基质。总而言之，本研究结果表明，凝结的血液、变性细胞和细胞碎片的区域在牙本质桥接后的初始牙本质桥接中具有重要作用。活髓切断术。