Experimental study about the effect of the calcium phosphate paste to the central nervous system in the cranio-maxillo-facial area

磷酸钙糊剂（CPP）具有良好的生物相容性和骨传导性。在颅颌面外科和骨科的临床病例中，CPP的应用取得了满意的效果。但CPP存在流入颅内的风险，其对中枢神经系统的安全性尚未得到证实。本研究将CPP植入日本白色家兔的骨缺损中，研究CPP对颅颌面部中枢神经系统的影响。第1组（n=5），在去除颅骨和硬膜外后，将CPP植入脑表面。第2组（n=5）用手术刀切断硬膜外，用缝线修补后，将CPP植入硬膜外。第3组（n=5），硬膜外植入CPP。第4组（n=5），骨缺损处不接受CPP。通过脑脊液检查和血液检查评价CPP对中枢神经系统的影响。在所有标本中，CPP植入后均出现暂时性非细菌性脑膜反应。然而，所有家兔均未显示转化或瘫痪。在第1组中，非细菌性脑膜反应持续的时间略长于其他组，并在植入后56天恢复到术前标准。我们估计这是由于手术处理的程度和CPP没有带来任何不可逆的反应，中枢神经系统。结论：CPP在颅颌面部有应用的可能。

Calcium phosphate paste(CPP) has been showed to be able to be molded during operation with good biocompatibility and osteoconductivity in some literatures. In clinical cases of the cranio-maxillo-facial surgery and the orthopedic surgery, CPP was used to bring satisfactory results. However CPP has a risk of flowing into the intra-cranial cavity and the safety of CPP to the central nervous system has not been showed yet. In this study, we implanted CPP into bone defects in Japanese White rabbits to study the effect of the CPP to the central nervous system in the cranio-maxillo-facial area. In group 1(n=5) , CPP was implanted on the surface of brain after the cranial bone and epidural were removed. In group 2(n=5) , CPP was implanted on epidural after the epidural was cut with the surgical knife and repaired with thread. In group 3(n=5) , CPP was implanted on epidural. In group 4(n=5) , no CPP was received in bone defects. The effect of the CPP to the central nervous system was evaluated by cerebrospinal fluid test and blood test. In all of the specimens, temporarily non-bacterial meningeal reactions revealed after the implantation of CPP. However any rabbit did not reveal conversion or paralysis. In group 1, non-bacterial meningeal reactions continued a little longer than in other groups and restored to the pre-operative standard by 56 days after the implantation. We have estimated that this was due to the degree of surgical handling and CPP did not bring any unreversible reactions to the central nervous system. We conclude that CPP has possibility of being utility in the cranio-maxillo-facial area.