Osman Reham B, Alharbi Nawal M
Professor at Prosthodontics Department, Faculty of Dentistry, Cairo University, Egypt.
Associate Professor at Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
J Dent. 2025 Jun 6;161:105875. doi: 10.1016/j.jdent.2025.105875.
To evaluate the influence of preparation design, build orientation and interaction between these two factors on the accuracy of veneers 3D printed using tilted stereolithography technology (TSLA).
Three maxillary central incisor typodont models were prepared to receive a full veneer preparation with three finish line designs: Cl I; labial reduction, Cl II; labial with butt joint incisal reduction and Cl III; labial and incisal overlap design then digitized to design the restorations which were 3D-printed using ceramic filled composite material (Dfab; DWS)(IrixMax monochrome A2; DWS)(N = 90). In each group, three subgroups were defined based on the build orientation (N = 10): 90°, 75° and 45° angles. Accuracy was evaluated using metrology software. Two-way Analysis of Variance (ANOVA) test was used to detect the differences between the groups (α=0.05).
Two-way ANOVA revealed a statistically significant interaction between different build angles and preparation design on RMSE trueness values (P = .003) and RMSE precision values (P = .001) Tukey post hoc test revealed that Cl II design had significantly lower RMSE values compared to both Cl I and Cl III designs (P<.001). 45° angle revealed significantly higher RMSE values compared to 75° and 90° build angles with P values .017 and .009 respectively.
Both preparation design and build orientation have an influence on the accuracy of TSLA printed laminate veneers. Butt-joint preparation design exhibited highest trueness compared to both window and incisal wrap designs. Among all finish line designs, 45° build angle exhibited the most significant deviation values and is not recommended for printing veneers using TSLA technology.
The preparation design that best fits a given clinical situation should be selected. The print angle that yields the highest accuracy relative to the clinically selected and executed tooth preparation design should be chosen. With different veneer preparation designs, 45° build angle provides the highest deviation values with chairside TSLA printers and should be avoided when printing resin-based, monochromatic laminate veneers.
评估制备设计、打印方向以及这两个因素之间的相互作用对使用倾斜立体光刻技术（TSLA）3D打印贴面精度的影响。
制备三个上颌中切牙模型，进行全瓷贴面制备，有三种肩台设计：I型；唇面磨除，II型；唇面加对接切端磨除，III型；唇面和切端重叠设计，然后数字化设计修复体，使用陶瓷填充复合材料（Dfab；DWS）（IrixMax单色A2；DWS）进行3D打印（N = 90）。在每组中，根据打印方向定义三个亚组（N = 10）：90°、75°和45°角。使用计量软件评估精度。采用双向方差分析（ANOVA）检验检测组间差异（α = 0.05）。
双向ANOVA显示，不同打印角度和制备设计之间在RMSE真实度值（P = .003）和RMSE精度值（P = .001）上存在统计学显著交互作用。Tukey事后检验显示，与I型和III型设计相比，II型设计的RMSE值显著更低（P < .001）。45°角的RMSE值与75°和90°打印角度相比显著更高，P值分别为.017和.009。
制备设计和打印方向均对TSLA打印的层压贴面精度有影响。与开窗和切端包裹设计相比，对接制备设计显示出最高的真实度。在所有肩台设计中，45°打印角度显示出最显著的偏差值，不建议使用TSLA技术打印贴面。
应选择最适合特定临床情况的制备设计。应选择相对于临床选择和执行的牙齿制备设计产生最高精度的打印角度。对于不同的贴面制备设计，45°打印角度在椅旁TSLA打印机中提供最高的偏差值，在打印基于树脂的单色层压贴面时应避免。
