Development of artificial tooth root by the Zirconia ceramics

为了明确氧化锆陶瓷人工牙根的基本性能，本文对氧化锆陶瓷牙种植体的组织病理学和氧化锆陶瓷钉的力学性能进行了研究：1.制作了直径为3 mm、长度为25 mm的氧化锆陶瓷钉，并将其植入拔牙后2个月的雄猴下磨牙区残留牙槽嵴。术后2个月进行组织病理学检查。1）种植体周围组织与正常牙牙周组织有新的组织成分区别。而所谓的厚纤维包膜几乎不出现在种植体界面。2)氧化锆陶瓷植入体直接接触植入体支撑骨。2.实验材料为直径4 mm、长40 mm的股骨颈，磨削深度0.5mm、螺距1.25mm的螺钉，磨削刀具有5种形状。研究了悬臂梁加载和三点弯曲对压碎它们所需的载荷的影响。1)直径为4 mm的锆英石钉在磨削深度为0.5mm的螺杆时，其强度下降了约50%，但在不同的磨削刀具形状下，其强度差别不大。2)在悬臂梁应力作用下，其强度约为16 kgf，可承受多晶氧化铝陶瓷的3倍左右的载荷。

For the sake of clearifying the fundemental property of the artificial tooth root of the zirconia-ceramics, Histo-pathorogical aspects on the zirconia-ceramics dental implant and mechanical property of the zirconia-ceramics pin were studied.1.The zirconia-ceramics pins with 3 mm in diameter and 25 mm in length were made, and they were implanted on the residual ridge of lower molar region of male monkeys two months after extraction of teeth. Pathological examination was taken two months after implantation of them.1)Peri-implant tissues were distinguished from the normal tooth periodontium by newly tissue elements. And so called thick fibrous capsulation almost never appeared at the interface of the implant body. 2)The zirconia-ceramics implant bodies directly contacted the implant supporting bone. And it is also observed that the Harvers canal were constructed with the newly bone tissue and implant body.2.The materials of the investigation were collum of 4 mm in diameter and 40 mm in length, and they grinded the screw with 0.5 mm in depth and 1.25 mm in pitch, The shapes of grinding cutter were 5 kinds. The cantilever loading and three point bending were studied on the load required to crush them. 1)The strength of the pin of 4 mm in diameter of the zirconia-ceramics decreases on the grinding to the screw with 0.5 mm in depth for about 50% of the pin of 3 mm in diameter, however, the strength is a little difference on the shapes of grinding cutter. 2)The strength showed about 16 kgf on the load of cantilever stress, and it may be bear about three times on the load of poly-crystal alumina-ceramics.