Alves Célia C, Muñoz Fernando, Cantalapiedra António, Ramos Isabel, Neves Manuel, Blanco Juan
Department of Estomatology, University of Santiago de Compostela, Santiago, Spain.
School of Veterinary of Lugo, University of Santiago de Compostela, Santiago, Spain.
Clin Oral Implants Res. 2015 Sep;26(9):983-91. doi: 10.1111/clr.12385. Epub 2014 Apr 16.
The effect on the marginal peri-implant tissues following repeated platform switching abutment removal and subsequent reconnection was studied.
Six adult female Beagle dogs were selected, and Pm3 and Pm4 teeth, both left and right sides, were extracted and the sites healed for 3 months. At this time, 24 bone level (BL) (Straumann, Basel, Switzerland) Ø 3.3/8 mm implants were placed, 2 in each side on Pm3 and Pm4 regions. In one side (control group), 12 bone level conical Ø 3.6 mm healing abutments and, on the other side (test group), 12 Narrow CrossFit (NC) multibase abutments (Straumann) , Basel, Switzerland) were connected at time of implant surgery. On test group, all prosthetic procedures were carried out direct to multibase abutment without disconnecting it, where in the control group, the multibase abutment was connected/disconnected five times (at 6/8/10/12/14 weeks) during prosthetic procedures. Twelve fixed metal bridges were delivered 14 weeks after implant placement. A cleaning/control appointment was scheduled 6 months after implant placement. The animals were sacrificed at 9 months of the study. Clinical parameters and peri-apical x-rays were registered in every visit. Histomorphometric analysis was carried out for the 24 implants. The distance from multibase abutment shoulder to the first bone implant contact (S-BIC) was defined as the primary histomorphometric parameter.
Wilcoxon comparison paired test (n = 6) found no statistically significant differences (buccal P = 0.917; Lingual P = 0.463) between test and control groups both lingually and buccally for S-BIC distance. Only Pm3 buccal aBE-BC (distance from the apical end of the barrier epithelium to the first bone implant contact) (P = 0.046) parameter presented statistically significant differences between test and control groups. Control group presented 0.57 mm more recession than test group, being this difference statistically significant between the two groups (P < 0.001).
It can be conclude, within the limits of this animal study, that the connection/disconnection of platform switching abutments during prosthetic phase of implant treatment does not induce bone marginal absorption. Furthermore, it may present a negative influence in the buccal connective tissue attachment that becomes shorter anyway preventing marginal hard tissue resorption, especially in thin biotypes.
研究重复移除和随后重新连接平台转换基台对种植体周围边缘组织的影响。
选取6只成年雌性比格犬，拔除左右两侧的Pm3和Pm4牙齿，创口愈合3个月。此时，植入24颗骨水平（BL）（瑞士巴塞尔士卓曼公司）直径3.3/8 mm的种植体，在Pm3和Pm4区域每侧植入2颗。一侧（对照组）在种植手术时连接12个骨水平圆锥形直径3.6 mm的愈合基台，另一侧（试验组）连接12个窄型CrossFit（NC）多基台基台（瑞士巴塞尔士卓曼公司）。试验组在整个修复过程中直接使用多基台基台，不进行拆卸，而对照组在修复过程中（在6/8/10/12/14周）将多基台基台连接/拆卸5次。种植体植入14周后安装12个固定金属桥。在种植体植入6个月后安排清洁/检查预约。在研究9个月时处死动物。每次复诊时记录临床参数和根尖周X光片。对24颗种植体进行组织形态计量分析。将多基台基台肩部到种植体与骨的首次接触点（S-BIC）的距离定义为主要组织形态计量参数。
Wilcoxon配对比较检验（n = 6）发现，试验组和对照组在舌侧和颊侧的S-BIC距离上均无统计学显著差异（颊侧P = 0.917；舌侧P = 0.463）。仅Pm3颊侧的aBE-BC（屏障上皮顶端到种植体与骨的首次接触点的距离）参数（P = 0.046）在试验组和对照组之间存在统计学显著差异。对照组的退缩比试验组多0.57 mm，两组之间的这种差异具有统计学显著性（P < 0.001）。
在本动物研究的范围内，可以得出结论，种植治疗修复阶段平台转换基台的连接/拆卸不会引起骨边缘吸收。此外，它可能对颊侧结缔组织附着产生负面影响，无论如何颊侧结缔组织附着都会变短，从而防止边缘硬组织吸收，尤其是在薄型生物型中。
