Histological Analysis of the Periodonitium-like Tissues around Hydroxyapatite Implant

本研究的目的是探讨羟基磷灰石陶瓷作为根管-骨内种植体的可行性。初步观察了种植体周围的组织结构。本研究以猕猴上中切牙为实验材料，采用钢钻钻自根尖钻取，制备种植体窝洞。然后，将致密的羟基磷灰石植入物，长10 mm，最大直径2 mm，1/20锥形，从顶点插入腔中。我们立即重新种植了牙齿。这些牙齿用夹板固定在相邻的牙齿上一个月。术后5个月，将患牙连同周围组织解剖，用10%福尔马林酒精固定。将它们包埋在聚酯树脂中并制备不脱钙切片。结果：1）5个月时，所有实验组均未发现牙体强直。2)3）种植体周围可见纤维束，将新生硬组织与周围骨组织连接起来。这些组织与完整的牙齿非常相似。在这项研究中，牙周组织能够在羟基磷灰石植入物周围分化。这些结果表明，羟基磷灰石陶瓷作为根管-骨内种植体的应用是有效的。

The purpose of this study was to investigate the possibility of applying hydroxyapatite ceramics as endodontic-endosseous implants. We preliminarily observed the tissues around the implants, which were pushed out from the root apexes. The upper medical incisors of monkeys were used for this study.To prepare the implant cavities, the teeth were extracted and drilled from the apexes by steel bur. Then, dense hydroxyapatite implants, 10mm in length, 2mm in maximum diameter and 1/20 tapered, were inserted into the cavity from the apexes. Immediately we replanted the teeth. The teeth were splinted to the neighbouring teeth for a month. Five months after the operation, the teeth with surrounding tissues were dissected and fixed by 10% formalin alcohol. They were embedded in polyester resin and undecalcified sections were prepared. The sections were stained with toluidin blue and obsereved under light microscope and transmission electron microscope.Results : 1)At 5 months, no teeth ankylosis was observed. 2)There was newly formedhard tissue which extended from the root cementum, on the surface of the implant, 3)Fiber bundles were observed around the implants which connected the newly formed hard tissue to the surrounding bone. These tissues were very similar to a intact tooth.In this study, peridontal tissues were able to differentiate around hydroxyapatite implants. So these findings indicate that the application of hydroxyapatite ceramics as an endodontic-endosseous implant is effective.