Miyata Takashi, Kobayashi Yukinao, Araki Hisao, Ohto Takaichi, Shin Kitetsu
Department of Periodontology, School of Dentistry, Meikai University, Saitama, Japan.
Int J Oral Maxillofac Implants. 2002 May-Jun;17(3):384-90.
The purpose of this study was to observe, after removing occlusal trauma and conducting plaque control, possible macroscopic and histologic changes in peri-implant tissue that had deteriorated resulting from experimental peri-implantitis, and to investigate the necessity for treatment procedures for peri-implantitis.
Four monkeys (Macaca fascicularis) in good general health were used in this experiment. Three months after the second premolar and the first molar were extracted from the right mandible, 2 IMZ experimental implants were placed in each monkey. After a 3-month osseointegration period, a second surgery was conducted, followed by making an impression for fabrication of the prosthesis. Excessive occlusal height of the prosthesis was adjusted to 250 microm, and the experiment was continued for 8 weeks after placement of the prosthesis. Three models were created: (1) A superstructure with an excessive occlusal height was used for 8 weeks without any brushing (positive control, model P); (2) after the first 4 weeks with a prosthesis with excessive occlusal height and no brushing, the superstructure was removed and not used for the last 4 weeks while brushing was conducted (experimental model, model E); and (3) for 8 weeks, a prosthesis with an appropriate occlusal height was used with brushing (negative control, model N).
When these 3 models were compared with each other, macroscopic findings indicated inflammation only in model P. Mobility of implants was not seen in any model. Histopathologic observations revealed a slight difference between model E and model P in terms of the degree of inflammatory cell infiltration in the connective tissue.
No difference was found in the degree of bone resorption. Partial tearing was observed at the contact region between epithelial tissue and implant surfaces.
(1) The contact between implants and epithelial or connective tissue is fragile; (2) inflammation and occlusion must be controlled more prudently than in the case of natural teeth; and (3) once peri-implantitis has progressed, the control of occlusion and inflammation is probably not sufficient to promote the healing mechanism.
本研究的目的是观察在消除咬合创伤并进行菌斑控制后，因实验性种植体周围炎而恶化的种植体周围组织可能出现的宏观和组织学变化，并探讨种植体周围炎治疗程序的必要性。
本实验使用4只健康状况良好的猕猴（食蟹猴）。在从右侧下颌骨拔除第二前磨牙和第一磨牙3个月后，每只猕猴植入2枚IMZ实验性种植体。经过3个月的骨整合期后，进行第二次手术，随后制取印模以制作修复体。将修复体过高的咬合高度调整至250微米，并在放置修复体后持续实验8周。创建了3个模型：（1）使用咬合高度过高的上部结构8周，不进行任何刷牙（阳性对照，P模型）；（2）在最初4周使用咬合高度过高且不刷牙的修复体后，去除上部结构，在最后4周不使用修复体但进行刷牙（实验模型，E模型）；（3）使用咬合高度合适的修复体并刷牙8周（阴性对照，N模型）。
将这3个模型相互比较时，宏观观察结果表明仅P模型存在炎症。在任何模型中均未观察到种植体松动。组织病理学观察显示，E模型和P模型在结缔组织中炎症细胞浸润程度方面存在轻微差异。
在骨吸收程度方面未发现差异。在上皮组织与种植体表面的接触区域观察到部分撕裂。
（1）种植体与上皮或结缔组织之间的接触很脆弱；（2）与天然牙相比，必须更谨慎地控制炎症和咬合；（3）一旦种植体周围炎进展，控制咬合和炎症可能不足以促进愈合机制。
