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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.

用氢氧化钙对猴未发育的活髓恒牙进行活髓切断术。分别于术后0、6、9、12、24小时观察牙本质桥接情况，术后第2、3、4、7天光镜和电镜观察发现，离体牙髓立即用Ca（OH）_2覆盖后，在离体牙髓顶端形成一层0.5-0.88mm的坏死层。最明显的变化包括细胞细节的丢失，血管充血和频繁的小出血。但是，受影响的地区后来似乎没有扩大。6小时后，在牙髓浅层坏死组织内及上方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有类似的小体。电镜下，凝血块深层可见大量球状团簇和电子致密颗粒。球状星团中的有机基质由针状晶体和电子致密颗粒组成。此后，聚集聚集发展为粗颗粒，最后形成不规则形状的团块。第7天，成牙本质细胞样细胞混合成胶原纤维牙本质基质，提示血凝带、细胞碎片和变性细胞在活髓切断后牙本质桥形成中起重要作用。