基于无托槽隐形矫治装置的正颌手术导板及术后牵引装置的打印精度及物理机械性能评价

Orthognathic splints and intermaxillary traction devices based on invisible orthodontic devices:printing accuracy and physical and mechanical properties assessment

目的:计算机辅助设计并三维打印制作基于隐形矫治装置的正颌手术导板及术后牵引装置,并对其打印精度及物理机械性能进行体外评价。方法:采用计算机辅助设计技术虚拟设计基于隐形矫治装置的正颌手术导板及术后牵引装置,分别以尼龙材料及丙烯酸树脂材料三维打印制作手术导板及牵引装置各5套。将两种手术导板及牵引装置经锥形束CT扫描后得到的模型数据与术前设计数据比较,评估三维打印的精度,并测定物理机械性能。结果:尼龙材料在硬度、弯曲强度、拉伸强度方面的性能弱于丙烯酸树脂,但是在断裂延伸率和应力-应变曲线面积方面优于丙烯酸树脂材料(P<0.05)。尼龙材料制备的牵引装置在上颌及下颌脱位时表现出更大的脱位力及更大的牵引钩折断力(P<0.05)。结论:相较于丙烯酸树脂材料,尼龙材料有着更好的物理机械性能,符合基于隐形矫治装置的正颌手术导板及术后牵引装置的设计需求。

Aim:To design and 3D print orthognathic splints and intermaxillary traction devices based on invisible orthodontic devices,and assess their printing accuracy and physical and mechanical properties in vitro.Methods:The orthognathic splints and intermaxillary traction devices were virtually designed and 3D printed with nylon or acrylic resin(5 sets of each).The printing accuracy with 2 materials of orthognathic splints and intermaxillary traction devices were evaluated by comparing the data obtained from CBCT scanning and the preoperative design.The physical and mechanical properties were detected.Results:Nylon was inferior to acrylic resin in terms of hardness,bending strength and tensile strength,but its performance in elongation at break and the area of stress-strain curve was better than acrylic resin(P<0.05).The intermaxillary traction devices made with nylon exhibited greater dislocation force and required a higher force to destroy the traction hooks on the devices(P<0.05).Conclusion:Compared with commonly used acrylic resin in clinical practice,nylon offers better comprehensive properties,and meets the design requirements of the aligner orthognathic splints and intermaxillary traction devices.