An basic research on application of dental implants to irradiated bone -effects of HBO-

(1)高压氧（HBO）对羟基磷灰石（HA）种植体周围骨组织反应的影响观察了高压氧（HBO）对大鼠胫骨HA种植体周围骨组织反应的影响。20只大鼠经15-戈伊照射后3个月，在胫骨近端干骺端植入HA种植体，其中一半大鼠在手术前后进行一个疗程的HBO治疗。组织学检查愈合过程。进行组织形态学测量以量化髓腔中的骨小梁和HA-骨接触的百分比。HBO在一定程度上促进了辐照骨的骨小梁形成，加速了非辐照骨的骨重建，并改善了辐照骨和非辐照骨的HA-骨接触。这些结果表明，高压氧治疗将是有用的骨内植入物安装到照射骨。(2)高压氧对照射剂量影响的实验研究评价了高压氧（HBO）对大鼠胫骨照射后羟基磷灰石（HA）植入物周围组织反应的影响与照射剂量的关系。在15-或25-戈伊照射后3个月，将HA植入物安装在大鼠胫骨中。EBO在手术前后对一半的大鼠进行了实验。组织学检查愈合过程。骨小梁体积和HA-骨接触百分比通过组织形态计量学进行定量。结果表明，高压氧能促进照射后骨小梁形成和种植体-骨接触。然而，高剂量照射骨即使在HBO下仍有严重的辐射损伤。

(1) Histomorphometric evaluation of the effect of hyperbaric oxygenation on healing around hydroxylapatite implants in irradiated boneThe effect of hyperbaric oxygen (HBO) on the tissue reaction around hydroxylapatite implants(HA) in the irradiated tibia of rats was investigated. HA implants were installed in the tibial proximal metaphysis of 20 rats 3 months after 15-Gy irradiation.A course of HBO was carried out in half of the rats both before and after surgery. The healing process was examined histologically. Histomorphometric measurements were made to quantify the trabecular bone in the medullary cavity and the percentage of HA-bone contact. HBO improved, to some degree, the trabecular bone formation in the irradiated bone, accelerated the bone remodeling in the nonirradiated bone, and 'improved the HA-bone contact in both irradiated and nonirradiated bones. These results suggested that HBO treatment would be useful for the installation of endosteal implants into irradiated bone.(2) An experimental study on the effects of hyperbaric oxygen with respect to irradiation dosageThe effects of hyperbaric oxygen (HBO) on the tissue reaction around hydroxylapatite (HA) implants in the irradiated tibia of rats with respect to irradiation dosage were evaluated. HA implants were installed in the tibia of rats 3 months after 15- or 25-Gy irradiation. EBO had undergone on half the rats before and after surgery. Healing process was examined histologically. The trabecular bone volume and the percentage of HA-bone contact were quantified histomorphometrically. The results indicated that HBO improved trabecular bone formation and implant-bone contact after irradiations. However, the irradiation damage was still serious in high-dose irradiated bone even with HBO).