Thomas Achsah Ann, Daniel Angleena Y, Gandhi Nitasha, Roy Neethu, Varghese Kevin George, Wadhwa Samiksha, Mathew Jemin Elizabeth
Postgraduate Resident, Department of Prosthodontics and Crown & Bridge, Christian Dental College, Ludhiana, Punjab, India.
HOD & Professor, Department of Prosthodontics and Crown & Bridge, Christian Dental College, Ludhiana, Punjab, India.
J Prosthet Dent. 2023 Oct;130(4):611.e1-611.e7. doi: 10.1016/j.prosdent.2023.07.006. Epub 2023 Aug 28.
The development of digital dental technologies has enabled clinicians to use additive and subtractive manufacturing techniques to fabricate interim restorations. However, knowledge of the trueness and precision of such restorations fabricated using digital light processing (DLP) and computer-aided design and computer-aided manufacturing (CAD-CAM) methods is limited.
The purpose of this in vitro study was to assess and compare the accuracy of interim crowns fabricated using DLP and CAD-CAM methods.
A typodont mandibular first molar was prepared for a ceramic crown, and a digital scan (Medit T500) was obtained to design interim crowns by using the CAD software program. The CAD data were designated as the reference data. A total of 20 crowns were fabricated by DLP and CAD-CAM technology. The fabricated interim crowns were further scanned using a laboratory scanner and were superimposed with the CAD data by using a 3-dimensional (3D) point cloud assessing software program (CloudCompare) for the evaluation of trueness and precision. Root mean square values (RMS) were obtained for the evaluation of discrepancies. The Student t test was used to compare data as the Shapiro-Wilk test confirmed the normal distribution.
RMS values for the trueness values of the external and intaglio surfaces of the 3D printed and milled interim crown displayed no statistically significant differences (P>.05). Precision for the external surface reported significance (P<.05), whereas that for the intaglio surface reported no significance (P>.05).
The accuracy of interim crowns fabricated by using DLP was comparable with that of milled crowns. Both manufacturing systems produced a true reproduction of the CAD. As for precision, the external surface of the DLP interim crown was statistically different from that of the milled group as it relates to the CAD.
数字牙科技术的发展使临床医生能够使用增材制造和减材制造技术来制作临时修复体。然而，对于使用数字光处理（DLP）和计算机辅助设计与计算机辅助制造（CAD-CAM）方法制作的此类修复体的真实性和精度的了解有限。
本体外研究的目的是评估和比较使用DLP和CAD-CAM方法制作的临时冠的准确性。
为一颗陶瓷冠准备一个典型的下颌第一磨牙模型，并通过使用CAD软件程序进行数字扫描（Medit T500）以设计临时冠。将CAD数据指定为参考数据。通过DLP和CAD-CAM技术共制作20个冠。使用实验室扫描仪对制作的临时冠进行进一步扫描，并通过三维（3D）点云评估软件程序（CloudCompare）将其与CAD数据叠加，以评估真实性和精度。获得均方根值（RMS）以评估差异。由于Shapiro-Wilk检验证实数据呈正态分布，因此使用Student t检验比较数据。
3D打印和铣削的临时冠的外表面和内表面的真实性值的RMS值无统计学显著差异（P>0.05）。外表面的精度具有统计学意义（P<0.05），而内表面的精度无统计学意义（P>0.05）。
使用DLP制作的临时冠的准确性与铣削冠相当。两种制造系统都能真实再现CAD模型。至于精度，DLP临时冠的外表面与铣削组相比在与CAD模型的关系上有统计学差异。
