Clinic of General, Special Care and Geriatric Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
Clinic of General, Special Care and Geriatric Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
J Dent. 2023 Apr;131:104438. doi: 10.1016/j.jdent.2023.104438. Epub 2023 Jan 28.
The aim of this study was to compare the shear bond strength of relined CAD-CAM complete removable dental prosthesis (CRDP) resins with conventional heat-polymerized polymethylmethacrylate (PMMA) resin.
A total of 96 resin specimens in identical dimensions of 10 mm × 10 mm × 11 mm were fabricated for four study groups [#1- Conventional heat-polymerized group: n=24 (ProBase); #2- Milled#1: n=24 (Ivobase); #3- Milled#2: n=24 (Ivotion); #4- 3D-printed: n=24, (NextDent Denture 3D+)]. Twelve specimens in each group were sectioned in the middle to produce a 3 mm defect and then were relined using a conventional denture relining material. All specimens underwent thermocycling (5-55°C) for 10,000 cycles. The shear bond tests were carried out in a universal testing machine. One-way ANOVA and Tukey's test were used for statistical analysis (p<0.05). The two-parameter Weibull distribution values were calculated.
Relined 3D-printed specimens had a significantly lower shear bond strength when compared with conventional (p=0.0003) and milled groups (Milled#1: p=0.0004; Milled#2: p<0.0001). There were no differences in the shear bond strengths between the milled and conventional groups. Weibull distribution presented the highest shape value for the non-relined Milled#1 (22.83) group and the lowest values for the 3D-printed relined group (4.001).
The findings of this study conclude that the shear bond strength of the conventionally-relined 3D-printed resins used for fabricating CRDPs was inferior to the shear bond strength of conventionally-relined resins employed for manufacturing CRDPs using CAD-CAM milling and conventional heat-polymerization techniques.
When considering 3D-printing for the fabrication of CRDPs, it is recommended to employ it in clinical situations where a frequent need for denture relining is not expected.
本研究旨在比较 CAD-CAM 全口义齿修复用重衬树脂与传统热聚合聚甲基丙烯酸甲酯（PMMA）树脂的剪切粘结强度。
共制作 96 个尺寸相同的 10mm×10mm×11mm 的树脂试件，分为四组进行研究：#1-常规热聚合组：n=24（ProBase）；#2-铣削#1：n=24（Ivobase）；#3-铣削#2：n=24（Ivotion）；#4-3D 打印：n=24（NextDent Denture 3D+）。每组 12 个试件在中间部分切割 3mm 缺陷，然后使用常规义齿衬垫材料重衬。所有试件均经过 5-55°C 的热循环（10000 次）。在万能试验机上进行剪切粘结试验。采用单因素方差分析和 Tukey 检验进行统计学分析（p<0.05）。计算双参数 Weibull 分布值。
与传统组（p=0.0003）和铣削组（Milled#1：p=0.0004；Milled#2：p<0.0001）相比，重衬 3D 打印试件的剪切粘结强度显著降低。铣削组和传统组之间的剪切粘结强度无差异。Weibull 分布显示非重衬铣削#1（22.83）组的形状值最高，3D 打印重衬组（4.001）的形状值最低。
本研究结果表明，用于制作全口义齿修复体的常规重衬 3D 打印树脂的剪切粘结强度低于 CAD-CAM 铣削和传统热聚合技术制造全口义齿修复体时常规重衬树脂的剪切粘结强度。
在考虑 3D 打印制作全口义齿修复体时，建议在预计不需要频繁进行义齿衬垫的临床情况下使用。
