背景:无牙患者的恢复性治疗选择范围从传统假牙到固定修复。材料的适当选择极大地影响了固定修复体的寿命和稳定性。大多数假体部件通常由钛制成。陶瓷(例如氧化锆)和聚合物(例如PEEK和BIOHPP)最近已被包括在这些制造中。下颌运动产生复杂的应力和应变模式。下颌骨骨折可能是由于跌倒或事故产生的冲击力而导致的这些应力和应变超过了临界极限。因此,有必要评估不同修复体在不同载荷情况下无牙下颌骨的生物力学行为。
目的:本研究分析了在正常和冲击负荷情况下进行四种修复修复后下颌骨的生物力学行为。
方法:用固定修复体构建下颌模型,使用各种材料(例如钛,氧化锆和BIOHPP),在正面咬力下,最大切口,和下巴冲击力。从拉伸和压缩应力和应变的提取,以及下颌骨节段的总变形,研究了生物力学行为和临床情况。
结果:在正面咬伤下,使用修复体4,前体表现出最高的拉伸(60.34MPa)和压缩(108.81MPa)应力,而使用修复体3,髁和角度具有最低的拉伸(7.12MPa)和压缩(12.67MPa)应力。在最大切口下,最高的拉伸(40.02MPa)和压缩(98.87MPa)应力产生在皮质骨的前体使用修复4。此外,最低的拉伸(7.7MPa)和压缩(10.08MPa)应力产生在髁和角,分别,使用恢复3.在下巴撞击下,使用修复4在前体上产生最高的拉伸(374.57MPa)和压缩(387.3MPa)应力。此外,最低的拉伸(0.65MPa)和压缩(0.57MPa)应力在使用修复3的冠状过程中产生。对于所有加载方案,与其他节段相比,下颌骨的前体具有最高的应力和应变值。与传统的钛修复体2相比,修复体1(氧化锆)增加了下颌节段上的拉伸和压缩应力和应变,与修复3(BIOHPP)相反。此外,氧化锆植入物表现出比其他植入物更高的位移。
结论:在正常加载情况下,使用所有修复体时,下颌骨上的拉伸和压缩应力和应变均在允许范围内。在下巴冲击载荷情况下,修复体1和4损坏了下颌骨的前体。
BACKGROUND: Restorative treatment options for edentulous patients range from traditional dentures to fixed restorations. The proper selection of materials greatly influences the longevity and stability of fixed restorations. Most prosthetic parts are frequently fabricated from titanium. Ceramics (e.g. zirconia) and polymers (e.g. PEEK and BIOHPP) have recently been included in these fabrications. The mandibular movement produces complex patterns of stress and strain. Mandibular fractures may result from these stresses and strains exceeding the critical limits because of the impact force from falls or accidents. Therefore, it is necessary to evaluate the biomechanical behavior of the edentulous mandible with different restorations under different loading situations.
OBJECTIVE: This study analyzes the biomechanical behavior of mandibles after four prosthetic restorations for rehabilitation under normal and impact loading scenarios.
METHODS: The mandibular model was constructed with a fixed restoration, which was simulated using various materials (e.g. Titanium, Zirconia & BIOHPP), under frontal bite force, maximum intercuspation, and chin impact force. From the extraction of tensile and compressive stresses and strains, as well as the total deformation of mandible segments, the biomechanical behavior and clinical situations were studied.
RESULTS: Under frontal bite, the anterior body exhibited the highest tensile (60.34 MPa) and compressive (108.81 MPa) stresses using restoration 4, while the condyles and angles had the lowest tensile (7.12 MPa) and compressive (12.67 MPa) stresses using restoration 3. Under maximum intercuspation, the highest tensile (40.02 MPa) and compressive (98.87 MPa) stresses were generated on the anterior body of the cortical bone using restoration 4. Additionally, the lowest tensile (7.7 MPa) and compressive (10.08 MPa) stresses were generated on the condyles and angles, respectively, using restoration 3. Under chin impact, the highest tensile (374.57 MPa) and compressive (387.3 MPa) stresses were generated on the anterior body using restoration 4. Additionally, the lowest tensile (0.65 MPa) and compressive (0.57 MPa) stresses were generated on the coronoid processes using restoration 3. For all loading scenarios, the anterior body of the mandible had the highest stress and strain values compared with the other segments. Compared to the traditional titanium restoration.2, restoration.1(zirconia) increases the tensile and compressive stresses and strains on the mandibular segments, in contrast to restoration.3 (BIOHPP). In addition, zirconia implants exhibited higher displacements than the other implants.
CONCLUSIONS: In the normal loading scenario, the tensile and compressive stresses and strains on the mandible were within the allowable limits when all restorations were used. Under the chin impact loading scenario, the anterior body of the mandible was damaged by restorations 1 and 4.