Rea Massimiliano, Botticelli Daniele, Ricci Sara, Soldini Claudio, González Gladys González, Lang Niklaus P
Faculty of Dentistry, University of Medical Science, La Habana, Cuba.
Clin Oral Implants Res. 2015;26(1):90-5. doi: 10.1111/clr.12305. Epub 2013 Dec 9.
To evaluate the influence of different insertion torques on healing of implants loaded immediately or left unloaded.
In six Labrador dogs, all mandibular premolars and molars were extracted. After 4 months of healing, flaps were elevated, and two implant sites were prepared at each side of the mandible. The distal sites were prepared conventionally while the mesial sites were underprepared by 0.3 mm. As a consequence, different final insertion torques of about 30 Ncm at the distal and >70 Ncm at the mesial sites were recorded. Healing abutments were applied to the left and transmucosal abutments to the right side. Flaps were sutured, crown preparation of the upper right second and third premolars was performed, and impressions were taken. Within 24 h, crowns were cemented both to implants and teeth in the right side of the mouth. After 4 months, the animals were sacrificed and ground sections obtained for histological evaluation.
A higher buccal bony crestal resorption and a more apical position of the coronal level of osseointegration were found at the loaded compared with the unloaded sites. MBIC% and percentages of peri-implant mineralized tissue (MB%) were higher at the loaded compared with the unloaded sites. Moreover, a higher MBIC% was found at the lower compared with the higher final insertion torque.
Immediate loading does not seem to have a negative effect on osseointegration. High torque values for the immediate loading procedures were not necessary. Probably, low torque values, were sufficient to obtain primary stability and hence may provide better osseointegration than high torque value.
评估不同植入扭矩对即刻加载或未加载种植体愈合的影响。
选取6只拉布拉多犬，拔除所有下颌前磨牙和磨牙。愈合4个月后，掀起皮瓣，在下颌骨两侧各制备两个种植位点。远端位点按常规方法制备，而近中端位点制备不足0.3 mm。结果，记录到远端位点的最终植入扭矩约为30 Ncm，近中端位点大于70 Ncm。左侧应用愈合基台，右侧应用穿龈基台。缝合皮瓣，对右上颌第二和第三前磨牙进行牙冠预备并取印模。在24小时内，将牙冠粘固于口腔右侧的种植体和天然牙上。4个月后，处死动物，获取磨片进行组织学评估。
与未加载位点相比，加载位点出现更高的颊侧牙槽嵴顶吸收，且骨结合冠方水平位置更靠近根尖。与未加载位点相比，加载位点的平均骨结合指数百分比（MBIC%）和种植体周围矿化组织百分比（MB%）更高。此外，与较高的最终植入扭矩相比，较低的最终植入扭矩下MBIC%更高。
即刻加载似乎对骨结合没有负面影响。即刻加载程序不需要高扭矩值。低扭矩值可能足以获得初期稳定性，因此可能比高扭矩值提供更好的骨结合。
