Fundermental examination about support capability of dental implants at the bone developed by the maxillary sinus lift

本研究对上颌窦提升术中使用不同移植材料形成的骨组织的特性进行了研究。评估新形成的骨作为种植体支持基质的活性(力学性能)和与种植体的组织学亲和力。将4只Beagle犬的嘴部区域剃除后，切开皮肤，形成粘骨膜瓣。然后暴露两侧额窦的前壁，并使用电动牙科发动机创建约10×20 mm的开口。鼻窦膜被小心翼翼地抬高，以避免撕裂和植骨材料紧密地堆积在间隙中。移植材料分为4组：第1组，取自下颌骨并磨碎的自体骨；第2组，不可吸收HA；第3组，可吸收HA；第4组，自体骨复合HA。每种移植材料被放置在每只实验动物体内的两个不同的位置。术后6个月，通过钻孔采集移植部位的组织标本，制备组织学标本，每个移植部位植入2颗钛种植体。植入6个月后，对种植体进行扭矩测试。自体骨移植组、自体骨移植组和不可吸收骨移植组的扭矩分别为45N-cm、41N-cm和28N-cm。非可吸收HA组的扭矩值明显低于两组自体骨组。在后续研究中必须考虑的因素是测试样本数量较少以及必须确保种植体植入部位皮质骨厚度的一致性。

The present study investigated the properties of bone tissue formed using various graft materials in maxillary sinus lift and elevation procedures. Newly formed bone was assessed in terms of viability as a supporting matrix for implants (mechanical properties) and histological affinity to implant bodies.After shaving the rostral region of 4 Beagle dogs, a skin incision was made and a mucoperiosteal flap was created. The anterior walls of the frontal sinus on both sides were then exposed and an electrical dental engine was used to create openings measuring approximately 10 × 20 mm. The sinus membrane was elevated carefully to avoid tearing and bone grafting materials packed tightly into the space. The grafting materials were divided into 4 groups: Group 1, autogenous bone harvested from the mandible and ground into small pieces; Group 2, non-resorbable HA; Group 3, resorbable HA; and Group 4, autogenous bone mixed with HA. Each grafting material was placed in 2 separate locations in each of the experimental animals. Six months after the operation, tissue samples from the grafted sites were collected by trephination in order to prepare ^histological samples and 2 titanium implants were inserted into each of the grafted sites. Six months after placement, torque tests on the implants were conducted. Polished demineralized sections were also prepared in order to examine the differences in osseous tissue formed by the 4 bone grafting materials.The autogenous bone graft group, the autogenous bone graft+HA group and the non-resorbable HA group gave torque values of 45N-cm, 41N-cm and 28N-cm, respectively. The torque value of the non-resorbable HA group was significantly lower in comparison to the two autogenous bone groups. The small number of test samples and the necessity to ensure consistency in the thickness of the cortical bone at the implant placement sites are factors that must be addressed in follow-up studies.