Assistant Professor, Department of Dentistry Services, Vocational School of Health Services, Ondokuz Mayıs University, Samsun, Turkey.
Professor, Department of Prosthodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
J Prosthet Dent. 2020 Jun;123(6):874.e1-874.e7. doi: 10.1016/j.prosdent.2019.12.020. Epub 2020 Mar 5.
Laser sintering has several processing parameters, typically under the control of dental laboratory technicians. Laser scan speed is an important parameter, which has a significant effect on manufacturing time but may also affect the adaptation of restorations. However, limited information is available regarding its impact.
The purpose of this in vitro study was to evaluate the intaglio surface adaptation of laser-sintered cobalt-chromium single-crown frameworks sintered at laser scanning speeds of 1, 3, and 6 m/s.
A master bronze metal die was prepared and scanned by using a laboratory scanner to fabricate the metal frameworks for 4 groups (n=10). In group C, the frameworks were fabricated by using the lost-wax method (control). In group L1, L3, and L6, the frameworks were fabricated by using direct metal laser melting (DMLM) at laser scanning speeds of 1, 3, and 6 m/s. After fabrication, 3 scanning data sets were used to evaluate the intaglio surface adaptation: the master die, the intaglio surface of each metal framework, and each metal framework seated on the master die. The intaglio surface adaptation of the metal frameworks was evaluated by using a metrology software program. The data were statistically analyzed by using a 1-way ANOVA, the Tukey honestly significant difference test, and the Tamhane T2 test (α=.05).
The highest mean intaglio surface discrepancy value was obtained from group L6, and this was significantly different from the other 3 groups (P<.001). No significant intaglio surface discrepancy differences were found among the other groups.
The amount of intaglio surface discrepancy increased when the laser scanning speed reached 6 m/s.
激光烧结有几个加工参数，通常由牙科实验室技术人员控制。激光扫描速度是一个重要参数，它对制造时间有显著影响，但也可能影响修复体的适应性。然而，关于其影响的信息有限。
本体外研究的目的是评估以 1、3 和 6 m/s 的激光扫描速度烧结的激光烧结钴铬单晶冠架的凹面表面适应性。
制备一个青铜母模金属模具，然后使用实验室扫描仪对其进行扫描，以制造 4 组（n=10）的金属框架。在组 C 中，通过失蜡法（对照）制造框架。在组 L1、L3 和 L6 中，通过直接金属激光熔化（DMLM）以 1、3 和 6 m/s 的激光扫描速度制造框架。制造后，使用 3 个扫描数据集评估凹面表面适应性：母模、每个金属框架的凹面和每个金属框架安装在母模上。使用计量软件程序评估金属框架的凹面表面适应性。使用单向方差分析、Tukey Honestly Significant Difference 检验和 Tamhane T2 检验（α=.05）对数据进行统计分析。
组 L6 获得的平均凹面表面差异值最高，与其他 3 组有显著差异（P<.001）。其他组之间没有发现明显的凹面表面差异。
当激光扫描速度达到 6 m/s 时，凹面表面差异量增加。
