钛植入体过盈装配对下颌骨骨重建影响的数值研究

Numerical study of effects from interference fit in titanium implants on mandibular bone remodeling

目的研究下颌骨修复手术钛钉植入后由于过盈装配而产生的下颌骨内应力以及骨密度分布变化,探讨不同过盈量对下颌骨骨重建的影响。方法采用有限元方法,建立8种不同过盈量的钛钉过盈装配模型,利用骨重建理论中的应变能密度算法计算5%、10%、15%、20%、25%、30%、35%、40%过盈量模型在36个月内下颌骨应力和骨密度的变化。结果导向孔直径大于钛钉内径时,随着过盈量的增大,骨-钉界面的固定效果逐渐增强;而过盈量超过30%之后,反而会因为过高的过盈量引起大量骨的失效,造成钛钉固定作用的减弱。结论在下颌骨修复时,建议选择直径大小等于或略小于钛钉内径大小的导向孔。

Objective To investigate stress and bone density distribution changes in the mandible due to the interference fit in titanium dental implants for mandible reconstruction, and study the influence of interference magnitudes on mandibular bone remodeling. Methods Eight interference fit models with titanium implants were established by finite element method. Bone remodeling based on strain energy density （SED） algorithm was employed to investigate changes in stress and bone density of the mandible in the models during 36 months with inference magnitude of 5%, 10%, 1.5%, 20%, 25%, 30%, 35% and 40%, respectively. Results When the diameter of pilot hole was larger than the internal diameter of titanium screw, the increment of interference magnitude would gradually enhance the screw fixation at the bone-titanium dental implant interface. However, once the magnitude of interference exceeded 30%, the increase in interference magnitude might weaken the screw fixation due to the failure and loss of bone. Conclusions The diameter of pilot hole equal to or slightly smaller than the internal diameter of titanium screw is recommended for mandibular reconstruction.