Güngör Erdoğan Hamiyet, Keleş Mert, Yılmaz Burak
Department of Prosthetic Dentistry, Lokman Hekim University, Ankara, Turkey.
Department of Periodontology, Lokman Hekim University, Ankara, Turkey.
J Prosthodont. 2024 Sep 3. doi: 10.1111/jopr.13935.
The purpose of this finite element analysis (FEA) study was to analyze the stress distribution on prosthetic components of splinted and nonsplinted prostheses, bone, and implants with different crown height space (CHS).
Mandibular posterior segment was modeled with no resorption at the second premolar site and various amounts of resorption (0, 3, 6, and 9 mm) at the first molar site. Two adjacent implants (Straumann bone level implants, 4.1 mm×8 mm) were placed; at the second premolar site, the crown height was 8 mm and at the first molar site, the crown height varied (8, 11, 14, and 17 mm), depending on the amount of resorption. Both splinted and nonsplinted crowns were designed. Vertical and oblique loads of 400 N were applied to the crowns. von Mises stress was used to evaluate the stress distribution in the implant complex and maximum principal stress was used to evaluate the stress in the bone.
When oblique forces were applied, the highest von Mises stresses were observed for nonsplinted crowns in the 17 mm CHS group. The maximum principal and minimum principal stresses observed in bone under oblique loading increased with increased CHS for nonsplinted restorations.
Crown height affected the amount of stress in bone and implant components. When the crown height difference between two adjacent implants increases, splinting may be crucial.
本有限元分析（FEA）研究的目的是分析不同牙冠高度空间（CHS）的夹板式和非夹板式修复体、骨和种植体的修复组件上的应力分布。
下颌后段模型设定为第二前磨牙部位无吸收，第一磨牙部位有不同程度的吸收（0、3、6和9毫米）。植入两颗相邻种植体（士卓曼骨水平种植体，4.1毫米×8毫米）；在第二前磨牙部位，牙冠高度为8毫米，在第一磨牙部位，牙冠高度根据吸收程度而变化（8、11、14和17毫米）。设计了夹板式和非夹板式牙冠。对牙冠施加400 N的垂直和斜向载荷。采用冯·米塞斯应力来评估种植体复合体中的应力分布，采用最大主应力来评估骨中的应力。
施加斜向力时，在17毫米CHS组的非夹板式牙冠中观察到最高的冯·米塞斯应力。在斜向加载下，非夹板式修复体在骨中观察到的最大主应力和最小主应力随CHS增加而增加。
牙冠高度影响骨和种植体组件中的应力大小。当两个相邻种植体之间的牙冠高度差增加时，夹板固定可能至关重要。
