Postgraduate student, Department of Prosthodontics, College of Dentistry, Dankook University, Cheonan, Republic of Korea.
Associate Professor, Department of Prosthodontics, College of Dentistry, Dankook University, Cheonan, Republic of Korea.
J Prosthet Dent. 2018 Jun;119(6):1027.e1-1027.e7. doi: 10.1016/j.prosdent.2018.03.016.
Limited information is available regarding the mechanical properties of a partial removable dental prosthesis clasp fabricated by direct metal laser sintering (DMLS).
The purpose of this in vitro study was to measure the mechanical properties of cast clasps, DMLS clasps, and annealed DMLS clasps and to determine the correlation between cyclic bend loading, annealing, and mechanical properties.
Sixty half round clasp specimens were fabricated, with a length of 20 mm and a diameter of 1.5 mm at 10 mm from the tip. The specimens were divided into 6 groups (n=10). Twenty specimens were fabricated by casting (CS, CSAC), and 40 specimens were fabricated by DMLS (DS, DSAC, ADS, ADSAC). Of the DMLS specimens, 20 underwent annealing (ADS, ADSAC). Equivalent to 5 years of clinical use, 0.25 mm of bending was applied to group CSAC, DSAC, and ADSAC 14 600 times. After cyclic bending loads, a cantilever bend test was conducted on all groups, and the loads were measured. To compare the load values, 1-way ANOVA and the Tukey HSD test were performed and statistical significance among the groups was evaluated (α=.05). Scanning electron microscopy and energy-dispersive spectroscopy analyses were also used for surface morphology evaluation and element analysis.
Bending loads of the DMLS specimens were significantly lower than those of the cast specimens (P<.05). The influence of cyclic bending loads was significant for cast specimens (P<.05), but not for DMLS specimens (P>.05), in terms of variation of loads. Annealed DMLS specimens had significantly higher bending loads than DMLS specimens (P<.05).
The DMLS specimens had lower load values at 0.25 mm bending than cast specimens. The DMLS specimens were less influenced by cyclic bending loads than the cast specimens. Annealing increased load values of the DMLS specimens at 0.25 mm bending.
关于通过直接金属激光烧结（DMLS）制造的局部可摘义齿卡环的机械性能，可用的信息有限。
本体外研究的目的是测量铸造卡环、DMLS 卡环和退火 DMLS 卡环的机械性能，并确定循环弯曲载荷、退火和机械性能之间的相关性。
制作了 60 个半圆环卡环样本，长度为 20mm，距尖端 10mm 处直径为 1.5mm。样本分为 6 组（n=10）。20 个样本通过铸造（CS、CSAC）制造，40 个样本通过 DMLS（DS、DSAC、ADS、ADSAC）制造。在 DMLS 样本中，有 20 个进行了退火（ADS、ADSAC）。相当于临床使用 5 年，对 CSAC、DSAC 和 ADSAC 组施加 0.25mm 的弯曲，循环弯曲 14600 次。经过循环弯曲载荷后，对所有组进行悬臂弯曲试验，并测量载荷。为了比较载荷值，进行了单因素方差分析和 Tukey HSD 检验，并评估了组间的统计学意义（α=.05）。还进行了扫描电子显微镜和能谱分析，以评估表面形貌和元素分析。
DMLS 样本的弯曲载荷明显低于铸造样本（P<.05）。对于铸造样本，循环弯曲载荷的影响显著（P<.05），而对于 DMLS 样本则不显著（P>.05），在载荷变化方面。退火的 DMLS 样本的弯曲载荷明显高于 DMLS 样本（P<.05）。
DMLS 样本在 0.25mm 弯曲时的载荷值低于铸造样本。DMLS 样本受循环弯曲载荷的影响小于铸造样本。退火增加了 DMLS 样本在 0.25mm 弯曲时的载荷值。
