Nkenke Emeka, Lehner Bernhard, Fenner Matthias, Roman Fidel San, Thams Ulf, Neukam Friedrich Wilhelm, Radespiel-Tröger Martin
Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Germany.
Int J Oral Maxillofac Implants. 2005 Jan-Feb;20(1):39-47.
To assess the course of the stability and the failure rate of dental implants placed in the partially edentulous maxillae of minipigs.
Three months after tooth removal, implants were placed in 9 minipigs. Six implants (XiVE; Friadent, Mannheim, Germany) were placed on each side of the posterior maxilla after preparation of the implant sites either by an osteotome technique or with spiral drills. Implant stability was assessed by resonance frequency analysis (RFA) at the time of placement, at second-stage surgery (which took place after a healing periods of 1, 2, 3, 4, or 5 months), and after a loading period of 6 months.
Implant stability was significantly influenced by the healing period (P = .007). Implant stability decreased after 1 to 3 months of healing for both of the placement techniques and increased after a healing period of 4 months. After implant site preparation by an osteotome technique, 6 of 12 immediately loaded implants, 18 of 24 implants loaded after healing periods of 1 to 3 months, and 1 of 18 implants loaded after a healing period of 4 or 5 months were lost. After implant site preparation using spiral drills, 7 of 12 immediately loaded implants, 12 of 24 implants loaded after healing periods of 1 to 3 months, and 2 of 18 implants loaded after healing periods of 4 or 5 months were lost. Broad overlapping of confidence intervals for the number of implant failures revealed that there was no relevant difference between immediate and early functional loading for either of the 2 techniques.
Implant loading after healing periods of 1 to 3 months did not improve implant survival compared to immediate loading in the posterior maxillae of minipigs. Not until a healing period of 4 months was reached did implant stability begin to increase. Only when functional loading was started at this point in time was maximal implant survival achieved.
评估小型猪部分无牙上颌中种植体的稳定性过程及失败率。
拔牙3个月后，在9只小型猪体内植入种植体。通过骨凿技术或螺旋钻制备种植位点后，在每侧上颌后部植入6枚种植体（XiVE；德国曼海姆Friadent公司）。在种植体植入时、二期手术时（分别在愈合1、2、3、4或5个月后进行）以及6个月加载期后，通过共振频率分析（RFA）评估种植体稳定性。
愈合期对种植体稳定性有显著影响（P = 0.007）。两种植入技术在愈合1至3个月后种植体稳定性均下降，而在愈合4个月后稳定性增加。采用骨凿技术制备种植位点后，12枚即刻加载的种植体中有6枚、愈合1至3个月后加载的24枚种植体中有18枚、愈合4或5个月后加载的18枚种植体中有1枚丢失。采用螺旋钻制备种植位点后，12枚即刻加载的种植体中有7枚、愈合1至3个月后加载的24枚种植体中有12枚、愈合4或5个月后加载的18枚种植体中有2枚丢失。种植体失败数量的置信区间广泛重叠，表明两种技术在即刻和早期功能加载方面均无显著差异。
在小型猪上颌后部，与即刻加载相比，愈合1至3个月后进行种植体加载并未提高种植体存活率。直到愈合4个月时，种植体稳定性才开始增加。只有在此时开始功能加载，才能实现种植体的最大存活率。
