Resident, Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Munich, Germany.
Professor, Department of Prosthetic Dentistry, University Hospital, LMU Munich, Munich, Germany.
J Prosthet Dent. 2021 May;125(5):817-823. doi: 10.1016/j.prosdent.2019.12.026. Epub 2020 May 19.
Additive manufacturing has been proposed for the fabrication of occlusal devices. However, information about the mechanical properties of additively manufactured devices is lacking.
The purpose of this in vitro study was to evaluate the influence of the postpolymerization unit and artificial aging on the Martens hardness (HM) and indentation modulus (E) of different 3D-printed materials in comparison with a conventionally milled material.
Thirty disks (20 mm in diameter and 5 mm in thickness) were additively manufactured (D20 II, Rapidshape & Form 2) for each 3D-printed material (NextDent Splint, Formlabs Dental LT Clear, and Freeprint Splint). As a control, 10 disks of the same thickness were cut from a conventionally milled material (Temp Premium). Each specimen was measured for HM and E (ZHU 0,2) after fabrication. The specimens were stored in water at 37 °C and measured again after 2 and 4 weeks. The data were analyzed statistically by using the Kruskal-Wallis, Mann-Whitney U, and Wilcoxon tests (adjusted by Bonferroni correction α=.05/27=.002).
The highest influence on HM parameters was shown by artificial aging (partial eta squared: HM: η=0.840, E: η=0.855, P<.001), followed by the material (HM: η=0.690 E: η=0.845, P<.001) and the postpolymerization unit (HM: η=0.649, E: η=0.778, P<.001). Initial HM values ranged from 147 ±8.11 N/mm for Formlabs postpolymerized in Otoflash to 89.5 ±8.55 N/mm for Detax postpolymerized in the Labolight unit. E values ranged from 3.92 ±0.061 kN/mm for Formlabs postpolymerized in Otoflash to 2.48 ±0.212 kN/mm for Detax postpolymerized in the Labolight unit. In general, HM and E values decreased after water storage, whereas the values remained unchanged for the control group.
HM parameters of additively manufactured occlusal devices depend on postpolymerization strategy. Otoflash and Printbox result in higher HM and E values. The 3D-printed materials are more prone to artificial aging than the control group, which brings into question their long-term service.
增材制造已被提议用于制作咬合装置。然而，关于增材制造设备的机械性能的信息还很缺乏。
本体外研究的目的是评估后聚合单元和人工老化对不同 3D 打印材料的马氏硬度（HM）和压痕模量（E）的影响，并与传统铣削材料进行比较。
为每个 3D 打印材料（NextDent Splint、Formlabs Dental LT Clear 和 Freeprint Splint）添加制造（D20 II、Rapidshape & Form 2）30 个直径为 20 毫米、厚度为 5 毫米的圆盘。作为对照，从传统铣削材料（Temp Premium）中切割出 10 个相同厚度的圆盘。每个试件在制造后测量 HM 和 E（ZHU 0.2）。将试件在 37°C 的水中储存，2 周和 4 周后再次测量。使用 Kruskal-Wallis、Mann-Whitney U 和 Wilcoxon 检验（用 Bonferroni 校正 α=0.05/27=0.002 调整）对数据进行统计学分析。
人工老化对 HM 参数的影响最大（偏 eta 平方：HM：η=0.840，E：η=0.855，P<.001），其次是材料（HM：η=0.690，E：η=0.845，P<.001）和后聚合单元（HM：η=0.649，E：η=0.778，P<.001）。初始 HM 值范围从 Formlabs 在 Otoflash 中后聚合的 147±8.11 N/mm 到 Detax 在 Labolight 单元中后聚合的 89.5±8.55 N/mm。E 值范围从 Formlabs 在 Otoflash 中后聚合的 3.92±0.061 kN/mm 到 Detax 在 Labolight 单元中后聚合的 2.48±0.212 kN/mm。一般来说，水储存后 HM 和 E 值降低，而对照组的数值保持不变。
增材制造咬合装置的 HM 参数取决于后聚合策略。Otoflash 和 Printbox 导致更高的 HM 和 E 值。3D 打印材料比对照组更容易受到人工老化的影响，这使其长期服务受到质疑。
