Masters student in Dental Science, Department of General Dentistry, Faculty of Dental Medicine of Laval University, Québec, Canada; and Private practice, Montreal, Quebec, Canada.
Professor, Department of Restorative Dentistry, Faculty of Dental Medicine of Laval University, Québec, Canada.
J Prosthet Dent. 2024 Jul;132(1):108-114. doi: 10.1016/j.prosdent.2022.05.006. Epub 2022 Jun 30.
New fabrication techniques have been developed for removable partial denture (RPD) frameworks although studies validating the clinical application of these techniques are scarce.
The purpose of this clinical study was to compare the adaptation of RPD framework rests made with conventional casting or computer-aided design and computer-aided manufacturing (CAD-CAM) with selective laser sintering (SLS) at the clinical evaluation and 1 year after the delivery of the prostheses.
This triple-blinded pilot study included 18 participants presenting with maxillary and/or mandibular partial edentulism, of which only 7 returned for the second measurement 1 year after prosthesis delivery. Participants were randomly assigned to 1 of 2 groups depending on whether the RPD framework was made with SLS or conventional lost-wax casting. The adaptation of the RPD at the rest seat area was evaluated by injecting a silicone material on the abutment tooth before seating. The silicone specimens were then sectioned transversely and measured with a scanning electron microscope. The statistical analysis was performed with a linear mixed-effect model with the intention to treat and with a 3-factor repeated measures ANOVA (α=.05).
At the metal framework evaluation (T), the prostheses made with SLS showed a mean ±standard deviation adaptation of 398 ±45 μm, while those made with conventional casting presented a mean ±standard deviation adaptation of 176 ±41 μm (P=.009). One year after the delivery of the prostheses (T), the adaptation of the frameworks made with conventional casting was still significantly better (88 ±6 μm versus 197 ±94 μm, P=.03).
Frameworks made with SLS showed worse clinical accuracy at the rest than frameworks produced with conventional casting.
尽管已经开发出了用于可摘局部义齿（RPD）支架的新制造技术，但验证这些技术临床应用的研究却很少。
本临床研究的目的是比较常规铸造或计算机辅助设计和计算机辅助制造（CAD-CAM）与选择性激光烧结（SLS）制作的 RPD 支架在临床评估和修复体交付后 1 年时的固位情况。
本双盲试点研究纳入了 18 名上颌和/或下颌部分缺牙的患者，其中只有 7 名患者在修复体交付 1 年后返回进行第二次测量。参与者根据 RPD 支架是通过 SLS 还是常规失蜡铸造制造，随机分为 2 组。通过在就位前将硅橡胶材料注入基牙来评估 RPD 在支托区的适应性。然后将硅橡胶样本横向切割并使用扫描电子显微镜进行测量。统计分析采用意向治疗的线性混合效应模型和 3 因素重复测量方差分析（α=.05）。
在金属支架评估时（T），使用 SLS 制造的义齿的平均适应值为 398 ±45 μm，而使用常规铸造制造的义齿的平均适应值为 176 ±41 μm（P=.009）。修复体交付 1 年后（T），常规铸造制造的义齿的适应性仍然明显更好（88 ±6 μm 与 197 ±94 μm，P=.03）。
与常规铸造制造的义齿相比，使用 SLS 制造的义齿在支托处的临床精度较差。
