Gehrke Sergio Alexandre, Bragança Leana Kathleen, Velasco-Ortega Eugenio, Calvo-Guirado José Luis
Biotecnos Research Center, Calle Cuareim, 1483, CP: 11.100, Montevideo, Uruguay.
University Catholica San Antonio de Murcia (UCAM), Murcia, Spain.
Int J Implant Dent. 2018 Feb 12;4(1):5. doi: 10.1186/s40729-018-0120-z.
The aim of this study was to compare histologically the dimensional behavior of peri-implant tissues during osseointegration of immediately exposed or submerged implant placement in fresh extraction and healed sites.
Four fresh extraction and four delayed implant sites were placed in each hemimandible of five dogs at the bone crest level. In 2 implants of each side were installed a healing abutment (exposed) and two cover screw (submerged) and formed four groups: implant installed in fresh extraction submerged (group 1), implants in fresh extraction immediately exposed (group 2), implants installed in healed site submerged (group 3), and implants in healed site immediately exposed (group 4). After 12 weeks of healing period, histomorphometric analyses of the specimens were carried out to measure the crestal bone level values and the tissue thickness in the implant shoulder portion.
The measure of crestal bone level showed some higher values for implants installed in fresh extraction sites in the buccal aspect: 1.88 ± 0.42 mm for group 1 and 2.33 ± 0.33 mm for group 2, with statistical significance among all four groups tested (P < 0.001). For peri-implant tissue thickness, a significative higher statistical difference (P < 0.001) for implants installed in healed sites (groups 3 and 4) was found.
Within the limitations of the present animal study, our findings suggest that the implants placed in fresh extraction or healed site and with regards to the moment of exposition (immediately or no) are important factors to the amount of peri-implant tissues after remodeling over a period of 12 weeks. The null hypothesis was rejected.
本研究的目的是通过组织学比较在新鲜拔牙位点和愈合位点即刻暴露或埋入式种植体植入骨结合过程中种植体周围组织的尺寸变化情况。
在五只犬的每侧半下颌骨的牙槽嵴水平植入四个新鲜拔牙位点种植体和四个延期种植位点种植体。每侧的两个种植体安装愈合基台（暴露），两个安装覆盖螺丝（埋入），形成四组：新鲜拔牙位点埋入式种植体（第1组）、新鲜拔牙位点即刻暴露种植体（第2组）、愈合位点埋入式种植体（第3组）、愈合位点即刻暴露种植体（第4组）。愈合12周后，对标本进行组织形态计量学分析，测量种植体肩部的牙槽嵴骨水平值和组织厚度。
牙槽嵴骨水平测量显示，颊侧新鲜拔牙位点植入的种植体有一些较高的值：第1组为1.88±0.42毫米，第2组为2.33±0.33毫米，在所有四组测试中具有统计学意义（P<0.001）。对于种植体周围组织厚度，发现愈合位点植入的种植体（第3组和第4组）有显著更高的统计学差异（P<0.001）。
在本动物研究的局限性内，我们的研究结果表明，在新鲜拔牙位点或愈合位点植入的种植体，以及暴露时间（即刻或未即刻），是12周重塑后种植体周围组织量的重要影响因素。原假设被拒绝。
