Zerodonto founder, private practitioner, via Santa Lucia, 80132 Naples, Italy.
Calabrodental, via Enrico Fermi, 88900 Crotone, Italy.
J Mech Behav Biomed Mater. 2019 Feb;90:173-181. doi: 10.1016/j.jmbbm.2018.10.014. Epub 2018 Oct 15.
The experimental determination of local bone deformations due to implant loading would allow for a better understanding of the biomechanical behavior of the bone-implant-prosthesis system as well as the influence of uneven force distribution on the onset of implant complications. The present study aimed at describing an innovative in vivo strain gauge measurement technique to evaluate implant-to-bone force transmission, assessing whether and how oral implants can transfer occlusal forces through maxillary bones. In vivo force measurements were performed in the maxillary premolar region of a male patient who had previously received a successful osseointegrated titanium implant. Three linear mini-strain gauges were bonded onto three different buccal cortical bone locations (i.e. coronal, middle, apical) and connected to strain measuring hardware and software. A customized screw-retained abutment was manufactured to allow for vertical and horizontal loading tests. As to the vertical load test, the patient was instructed to bite on a load cell applying his maximum occlusal force for 20 s and then recovering for 10 s to restore the bone unstrained state; the test was repeated 20 times consecutively. As regards the horizontal load test, the implant was subjected to a total of 20 load applications with force intensities of 5 and 10 kg. During the tests, the recorded signals were plotted in real time on a graph as a function of time by means of a strain analysis software. The described strain gauge measurement technique proved to be effective in recording the forces transmitted from osseointegrated implants to the cortical bone. Horizontal loads caused higher deformations of cortical bone than vertical biting forces; in both situations, the deformation induced by the force transferred from the implant to the bone progressively decreased from the coronal to the apical third of the alveolar ridge. At approximately 9 mm from the implant neck, the effect of occlusal force transmission through osseointegrated titanium implants was negligible if compared to the apical region.
由于植入物加载导致的局部骨骼变形的实验确定，将有助于更好地理解骨-植入-假体系统的生物力学行为，以及不均匀力分布对植入物并发症发生的影响。本研究旨在描述一种创新的体内应变计测量技术，以评估植入物-骨之间的力传递，评估口腔种植体是否以及如何通过上颌骨传递咬合力。在一位先前成功接受骨整合钛植入物的男性患者的上颌前磨牙区域进行了体内力测量。三个线性微型应变计粘贴在上颌颊侧皮质骨的三个不同位置（即冠部、中部、根尖部），并与应变测量硬件和软件相连。制造了一个定制的螺钉固位基台，以允许进行垂直和水平加载测试。在垂直加载测试中，指导患者咬住一个加载单元，施加其最大咬合力 20 秒，然后恢复 10 秒以恢复未受应变的骨状态；测试连续重复 20 次。至于水平加载测试，总共对植入物施加了 20 次力，强度为 5 和 10 千克。在测试过程中，通过应变分析软件，实时将记录的信号作为时间的函数绘制在图表上。所描述的应变计测量技术被证明可有效地记录从骨整合植入物传递到皮质骨的力。水平力引起的皮质骨变形高于垂直咬合力；在两种情况下，由植入物传递到骨的力引起的变形从牙槽嵴的冠部逐渐减少到根尖部。在距植入物颈部约 9 毫米处，如果与根尖区相比，通过骨整合钛植入物传递咬合力的效果可以忽略不计。
