Armentia Mikel, Abasolo Mikel, Coria Ibai, Sainitier Nicolas
PhD student, Department of Mechanical Engineering, University of the Basque Country, Bilbao, Spain; Engineer, R&D Department, Biotechnology Institute I Mas D S.L., Miñano, Spain.
Associate Professor, Department of Mechanical Engineering, University of the Basque Country, Bilbao, Spain.
J Prosthet Dent. 2022 Mar;127(3):477.e1-477.e9. doi: 10.1016/j.prosdent.2021.12.010. Epub 2022 Jan 31.
Dental implant geometry affects the mechanical performance and fatigue behavior of butt-joint implant-supported restorations. However, failure of the implant component has been generally studied by ignoring the prosthetic screw, which is frequently the critical restoration component.
The purpose of this in vitro study was to evaluate the effect of 3 main implant geometric parameters: the implant body diameter, the platform diameter, and the implant-abutment connection type (external versus internal butt-joint) on the fatigue life of the prosthetic screw. The experimental values were further compared with the theoretical ones obtained by using a previously published methodology.
Four different designs of direct-to-implant dental restorations from the manufacturer BTI were tested. Forty-eight fatigue tests were performed in an axial fatigue testing machine according to the International Organization for Standardization (ISO) 14801. Linear regression models, 95% interval confidence bands for the linear regression, and 95% prediction intervals of the fatigue load-life (F-N) results were obtained and compared through an analysis of covariance (ANCOVA) to determine the influence of the 3 parameters under study on the fatigue behavior (α=.05).
Linear regression models showed a statistical difference (P<.001) when the implant body diameter was increased by 1 mm; an average 3.5-fold increase in fatigue life was observed. Increasing the implant abutment connection diameter by 1.4 mm also showed a significant difference (P<.001), leading to 7-fold longer fatigue life on average. No significant statistical evidence was found to demonstrate a difference in fatigue life between internal and external implant-abutment connection types.
Increasing the implant platform and body diameter significantly improved (P<.001) the fatigue life of the prosthetic screw, whereas external and internal connections provided similar results. In addition, experimental results proved the accuracy of the fatigue life prediction methodology.
牙种植体的几何形状会影响对接式种植体支持修复体的力学性能和疲劳行为。然而，种植体部件的失效通常是在忽略修复螺丝的情况下进行研究的，而修复螺丝往往是关键的修复部件。
本体外研究的目的是评估3个主要种植体几何参数，即种植体体部直径、平台直径和种植体-基台连接类型（外部对接与内部对接）对修复螺丝疲劳寿命的影响。将实验值与使用先前发表的方法获得的理论值进行进一步比较。
测试了来自制造商BTI的4种不同设计的直接种植牙修复体。根据国际标准化组织（ISO）14801在轴向疲劳试验机上进行了48次疲劳试验。通过协方差分析（ANCOVA）获得线性回归模型、线性回归的95%区间置信带以及疲劳载荷-寿命（F-N）结果的95%预测区间，并进行比较，以确定所研究的3个参数对疲劳行为的影响（α = 0.05）。
当种植体体部直径增加1 mm时，线性回归模型显示出统计学差异（P < 0.001）；观察到疲劳寿命平均增加3.5倍。种植体基台连接直径增加1.4 mm也显示出显著差异（P < 0.001），导致疲劳寿命平均延长7倍。没有发现显著的统计证据表明内部和外部种植体-基台连接类型在疲劳寿命上存在差异。
增加种植体平台和体部直径显著提高了（P < 0.001）修复螺丝的疲劳寿命，而外部和内部连接提供了相似的结果。此外，实验结果证明了疲劳寿命预测方法的准确性。
