Ogiso M, Tabata T, Nakabayashi N, Yamashita Y, Borgese D
Faculty of Dentistry, Tokyo Medical and Dental University, Japan.
J Long Term Eff Med Implants. 1993;3(1):69-79.
Abutment and root portion divided two-piece dental implants were designed to modify the one-piece dense hydroxyapatite (D-HAP) implant. The initial placement of the root portion endosseously ensured an aseptic environment and physical stability for the implant during the bone healing period. The outer D-HAP shell of the root portion was fortified by an inner titanium cylinder and cemented with an adhesive resin cement containing 4-methacryloyoxyethyl trimellitate anhydride (4-META) and reinforced by fine apatite filler. Upon attaining integration of the bone and implant, the abutment was screwed and fixed into the screw hole of the root portion. The tissue response of both the apatite-filled resin cement and root portion of the two-piece implant was studied by animal canine experiments. Light and electron microscopic examination of specimens taken from experimental animal tissue showed bone contacted directly not only the exposed apatite filler at the surface of the apatite-filled resin cement, but also the resin portion. These findings of direct bone contact suggested that the tissue response of apatite-filled resin cement was approximately similar to the usual D-HAP. Because most of the surface of the outer D-HAP shell of the root portion came in contact with bone, it prevented the deposition of contamination on the D-HAP surface during the manufacturing procedures of the root portion.
基台与牙根分体式牙种植体旨在改进一体式致密羟基磷灰石（D-HAP）种植体。牙根部分的初始骨内植入可确保种植体在骨愈合期处于无菌环境并具备物理稳定性。牙根部分的外部D-HAP外壳由内部钛圆柱体加固，并用含4-甲基丙烯酰氧基乙基偏苯三酸酐（4-META）的粘结树脂水门汀粘结，并由细磷灰石填料增强。在骨与种植体实现整合后，将基台旋拧并固定到牙根部分的螺孔中。通过犬类动物实验研究了磷灰石填充树脂水门汀和分体式种植体牙根部分的组织反应。对取自实验动物组织的标本进行光镜和电镜检查发现，骨不仅直接接触磷灰石填充树脂水门汀表面暴露的磷灰石填料，还接触树脂部分。这些直接骨接触的发现表明，磷灰石填充树脂水门汀的组织反应与普通D-HAP大致相似。由于牙根部分外部D-HAP外壳的大部分表面与骨接触，它可防止在牙根部分制造过程中污染物沉积在D-HAP表面。
