Ayali Aysa, Altagar Mazen, Ozan Oguz, Kurtulmus-Yilmaz Sevcan
Near East University, Faculty of Dentistry, Department of Oral and Maxillofacial Surgery, Nicosia Cyprus, Mersin 10, Turkey.
Near East University, Faculty of Dentistry, Department of Prosthodontics, Nicosia Cyprus, Mersin 10, Turkey.
Comput Biol Med. 2020 Aug;123:103880. doi: 10.1016/j.compbiomed.2020.103880. Epub 2020 Jul 5.
Patients with severely atrophied jaws can be challenging in implantology. The All-on-4 treatment concept eliminates advanced augmentation procedures in highly resorbed ridges by preserving the relevant anatomic structures. In addition, the inclination of the distal implants enables the placement of longer implants. Hence, tilting the anterior implants allows longer implant placement, in line with the distal implants of the All-on-4 concept. This study compared the biomechanical aspects of the standard All-on-4 treatment concept with the M-4 and V-4 techniques.
A three-dimensional model of an edentulous maxilla was created to perform three-dimensional finite element analysis. Three different configurations (All-on-4, M-4, and V-4) were modeled by changing the tilt angle of the anterior implants. In each model, to simulate a foodstuff, a solid spherical material was placed on the midline of the incisors and the right first molar region, separately applying an occlusal load of 100 Newtons. The maximum principal stress and minimum principal stress values were acquired for cortical bone, and von Mises stress values were obtained for ductile materials.
According to the present study's findings, although there were no considerable differences among the models, in general, the All-on-4 group demonstrated slightly higher stresses and the M-4 and V-4 group showed lower stresses.
M-4 or V-4 configurations may be used in cases of severely atrophied anterior maxillae to achieve better primary stabilization.
严重萎缩颌骨的患者在种植学中具有挑战性。All-on-4治疗理念通过保留相关解剖结构,消除了在高度吸收牙槽嵴上进行的高级增量手术。此外,远端种植体的倾斜度使得能够植入更长的种植体。因此,倾斜前部种植体可实现更长种植体的植入,这与All-on-4理念的远端种植体一致。本研究比较了标准All-on-4治疗理念与M-4和V-4技术的生物力学方面。
创建无牙上颌的三维模型以进行三维有限元分析。通过改变前部种植体的倾斜角度对三种不同的配置(All-on-4、M-4和V-4)进行建模。在每个模型中,为模拟食物,将实心球形材料分别放置在中切牙中线和右侧第一磨牙区域,分别施加100牛顿的咬合负荷。获取皮质骨的最大主应力和最小主应力值,并获得韧性材料的冯·米塞斯应力值。
根据本研究结果,尽管各模型之间没有显著差异,但总体而言,All-on-4组的应力略高,M-4和V-4组的应力较低。
对于严重萎缩的上颌前部病例,可采用M-4或V-4配置以实现更好的初期稳定性。