Purpose: 3D printing techniques have been widely used for manufacturing complex parts for various dental applications. For achieving suitable mechanical strength, post-cure processing is necessary, where the relative time duration and temperature specification also needs to be defined. The purpose of this study/paper is to assess the effects of post curing conditions and mechanical properties of 3D printed clear dental aligners. Design/methodology/approach: Dental long-term clear resin material has been used for 3D printing of dental aligners using a Formlabs 3D printer for direct usage on patients. Post-curing conditions have been varied, all of which have been subjected to mechanical compression loading of 1,000 N to evaluate the curing effects on the mechanical strength of the aligners. Findings: The experimental studies provide significant insight into both temperatures and time durations that could provide sufficient compressive mechanical strength to the 3D printed clear dental aligners. It was observed that uncured aligners deformed plastically with large deformations under the loading conditions, whereas aligners cured between 400°C–800°C for 15–20 min deformed elastically before fragmenting into pieces after safely sustaining higher compressive loads between 495 N and 666 N. The compressive modulus ratio for cured aligners ranged between 4.46 and 5.90 as compared to uncured aligners. For shorter cure time durations and lower temperature conditions, an appropriate elevated compressive strength was also achieved. Originality/value: Based on initial assessments by dental surgeons, suitable customised clear aligners can be designed, printed and cured to the desired levels based on patient’s requirements. This could result in time, energy and unit production cost savings, which ultimately would help to alleviate the financial burden placed on both the health service and their patients.

中文翻译：

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后固化条件对 3D 打印透明牙齿矫正器机械性能的影响

目的：3D 打印技术已广泛用于制造各种牙科应用的复杂零件。为了获得合适的机械强度，后固化处理是必要的，其中还需要定义相对持续时间和温度规范。本研究/论文的目的是评估 3D 打印的透明牙齿矫正器的后固化条件和机械性能的影响。设计/方法/方法：牙科长期透明树脂材料已用于使用 Formlabs 3D 打印机直接用于患者的牙齿矫正器的 3D 打印。后固化条件有所变化，所有这些条件都经受了 1,000 N 的机械压缩载荷，以评估固化对矫治器机械强度的影响。发现：实验研究提供了对温度和持续时间的重要见解，可以为 3D 打印的透明牙齿矫正器提供足够的压缩机械强度。据观察，未固化的矫正器在加载条件下发生塑性变形并产生较大的变形，而在 400°C–800°C 之间固化 15–20 分钟的矫正器会发生弹性变形，然后在安全地承受 495 N 到 666 N 之间的更高压缩载荷后碎裂成碎片. 与未固化矫正器相比，固化矫正器的压缩模量比介于 4.46 和 5.90 之间。对于较短的固化持续时间和较低的温度条件，还实现了适当的提高的抗压强度。原创性/价值：根据牙科医生的初步评估，可以设计合适的定制透明矫正器，根据患者的要求打印并固化到所需的水平。这可能会节省时间、能源和单位生产成本，最终将有助于减轻医疗服务及其患者的经济负担。