Mudhaffer Shaymaa, Haider Julfikar, Silikas Nick, Satterthwaite Julian
Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK; Substitutive Dental Sciences, Faculty of Dentistry, Taibah University, Madinah, Saudi Arabia.
Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK; Department of Engineering, Manchester Metropolitan University, Manchester, UK.
Dent Mater. 2025 Jun;41(6):745-754. doi: 10.1016/j.dental.2025.04.005. Epub 2025 Apr 18.
With the advent of digital technology in dentistry, manual methods for creating dental restorations are being replaced by digital CAD/CAM processes involving three-dimensional (3D) printing and milling. Marginal degradation and chipping are common issues, yet the literature on the edge strength of 3D-printed restorative materials remains limited. Uncertainties remain regarding the impact of print orientation on edge strength, necessitating further investigation to ensure clinical efficacy.
The purpose of this study was to evaluate the influence of print orientation on the edge strength of 3D-printed dental restorative resins indicated for definitive and interim use and compare them with milled materials.
Specimens (14 ×14 ×2 mm) were additively manufactured in three orientations (0, 45, and 90 degrees) using five 3D printed resins: VarseoSmile Crown (VCP), Crowntec (CT), Nextdent C&B MFH (ND), Dima C&B temp (DT), and GC temp print (GC). A DLP 3D printer (ASIGA MAX UV) was used, with post-processing parameters set according to manufacturer recommendations. Edge strength was measured at 0.5 mm and 1 mm distance from the edge using a CK 10 testing machine. Specimens were tested in dry conditions (0.5 mm) and after 48 hours of storage in artificial saliva at 37°C (0.5 mm and 1 mm). Failure modes were analysed visually and using optical and scanning electron microscopy. Filler content was assessed using the Ash method, and statistical analysis was conducted using ANOVA. Pearson correlation was used to assess the relationship between filler weight and edge strength.
Due to severe deformation before chipping under load at both distances, data for the 3D-printed and milled interim materials were excluded. The 90-degree printing orientation of definitive materials demonstrated significantly higher edge strength after 48 hours in artificial saliva compared to the 0- and 45-degree orientations (P < 0.001). Significant differences were observed between the 3D printed and milled materials at 0.5 (P < 0.001) mm but not at 1 mm (P ≥ 0.804). Failure modes were predominantly surface indentation without visible cracking (58 %), followed by surface indentation with visible cracking (17 %), edge chipping (0.2 %), and specimen fracture (13 %). A non-significant negative correlation was observed between filler weight and edge strength (r = 0.161, P < 0.680).
Based on the current findings, 3D printing definitive resin materials at a 90-degree orientation provided increased edge strength. 3D-printed materials can better resist crack propagation compared to milled composites.
Optimizing the print orientation to 90-degree can improve the edge strength of definitive 3D printed materials.
随着牙科数字技术的出现，用于制作牙齿修复体的手工方法正被涉及三维（3D）打印和铣削的数字CAD/CAM工艺所取代。边缘降解和崩裂是常见问题，但关于3D打印修复材料边缘强度的文献仍然有限。打印方向对边缘强度的影响仍不确定，需要进一步研究以确保临床疗效。
本研究的目的是评估打印方向对用于最终和临时修复的3D打印牙科修复树脂边缘强度的影响，并将其与铣削材料进行比较。
使用五种3D打印树脂（VarseoSmile Crown（VCP）、Crowntec（CT）、Nextdent C&B MFH（ND）、Dima C&B temp（DT）和GC temp print（GC）），以三种方向（0度、45度和90度）增材制造试样（14×14×2mm）。使用DLP 3D打印机（ASIGA MAX UV），后处理参数根据制造商建议设置。使用CK 10测试机在距边缘0.5mm和1mm处测量边缘强度。试样在干燥条件下（0.5mm）以及在37°C人工唾液中储存48小时后（0.5mm和1mm）进行测试。通过肉眼以及光学和扫描电子显微镜分析失效模式。使用灰分法评估填料含量，并使用方差分析进行统计分析。使用Pearson相关性评估填料重量与边缘强度之间的关系。
由于在两个距离处加载时崩裂前严重变形，3D打印和铣削的临时材料的数据被排除。与0度和45度方向相比，最终材料在90度打印方向下在人工唾液中48小时后显示出显著更高的边缘强度（P < 0.001）。在0.5mm处3D打印和铣削材料之间观察到显著差异（P < 0.001），但在1mm处没有（P≥0.804）。失效模式主要是表面压痕且无可见裂纹（58%），其次是表面压痕且有可见裂纹（17%）、边缘崩裂（0.2%）和试样断裂（13%）。在填料重量与边缘强度之间观察到非显著的负相关（r = 0.161，P < 0.680）。
基于当前研究结果，以90度方向3D打印最终树脂材料可提高边缘强度。与铣削复合材料相比，3D打印材料能更好地抵抗裂纹扩展。
将打印方向优化为90度可提高最终3D打印材料的边缘强度。
Zotero 插件