Statement of problem

Studies that have analyzed the bond strength of resilient denture liners to milled denture bases are sparse, and the authors are unaware of research that has investigated the tensile bond strength of denture relining materials to 3D-printed denture bases.

Purpose

The purpose of this in vitro study was to evaluate the tensile bond strength of both hard and soft denture reline materials on denture bases fabricated by 3D printing and computer-aided design and computer-aided manufacture (CAD-CAM) milling technology.

Material and methods

Injected, milled, and printed denture base specimens were fabricated (n=30) and bonded to 5 different denture reline materials: soft chairside reline (Coe Soft and PermaSoft), hard chairside reline (Tokuyama Rebase ii and Kooliner), and hard laboratory reline (ProBase Cold). Specimens of each reline material were divided into 5 groups (n=10) and were placed in distilled water for 24 hours before tensile testing. Maximum tensile stress values before failure were recorded, and the failure mode was also determined. The type of failure was analyzed by a scanning electron microscope. Statistics were analyzed with 2-way ANOVA and multiple comparison tests (α=.05).

Results

Overall, no statistically significant difference in tensile bond strength was found in the injected, milled, and printed denture groups. However, the printed denture base group demonstrated significantly lower values of tensile bond strength (P<.05) with PermaSoft, Tokuyama Rebase ii, and ProBase Cold groups than other denture base groups (milled and injected). The milled denture bases had the highest mean value of tensile bond strength with 4 of the 5 denture relining materials tested (Coe Soft, PermaSoft, Tokuyama Rebase ii, and Kooliner). No statistically significant difference (P>.05) was found among the injected, milled, and printed denture bases when relined with Kooliner. When comparing the denture reline type, the lowest values were seen with the soft chairside relining materials, and highest values with the hard laboratory reline material. Among the modes of failure, adhesive failures were observed predominantly with the printed denture base materials relined with soft chairside relining materials, while cohesive and mixed modes of failure were found in the milled and injected denture base groups.

Conclusions

The printed denture bases had significantly lower tensile bond strength values than the injection and milled denture bases with the PermaSoft, Tokuyama Rebase ii, and ProBase Cold denture relines, while milled denture bases demonstrated the highest values of tensile bond strength for all chairside relining groups. In addition, the soft chairside relining materials showed the lowest tensile bond strength values regardless of the denture processing method with respect to the denture base type (injected, printed, and milled) compared with the hard relining materials.

中文翻译：

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CAD-CAM 技术制造的义齿基托上义齿衬里材料拉伸粘结强度的比较

问题陈述

分析弹性义齿衬里与铣削义齿基托的粘合强度的研究很少，作者不知道调查义齿衬里材料与 3D 打印义齿基托的拉伸粘合强度的研究。

目的

这项体外研究的目的是评估硬质和软质义齿衬里材料在通过 3D 打印和计算机辅助设计和计算机辅助制造 (CAD-CAM) 铣削技术制造的义齿基托上的拉伸粘合强度。

材料与方法

制造了注射、研磨和打印的义齿基托样本 (n=30) 并粘合到 5 种不同的义齿衬垫材料上：椅旁软衬垫（Coe Soft 和 PermaSoft）、椅旁硬衬垫（Tokuyama Rebase ii 和 Kooliner）和实验室硬衬垫（ProBase 冷）。每种衬里材料的样本被分成 5 组 (n=10)，并在拉伸测试前放置在蒸馏水中 24 小时。记录失效前的最大拉伸应力值，并确定失效模式。通过扫描电子显微镜分析故障类型。使用 2 向方差分析和多重比较检验 (α=.05) 分析统计数据。

结果

总体而言，在注射义齿组、铣削义齿组和打印义齿组中，未发现拉伸粘合强度存在统计学上的显着差异。然而，与其他义齿基托组（研磨和注射）相比，打印义齿基托组与 PermaSoft、Tokuyama Rebase ii 和 ProBase Cold 组相比，拉伸粘合强度值 ( P <.05) 显着较低。研磨义齿基托与测试的 5 种义齿衬里材料中的 4 种（Coe Soft、PermaSoft、Tokuyama Rebase ii 和 Kooliner）具有最高的拉伸粘合强度平均值。差异无统计学意义（P>.05) 在用 Kooliner 重新衬里时在注射、研磨和打印的义齿基托中被发现。比较义齿衬垫类型时，软椅边衬垫材料的值最低，实验室硬衬垫材料的值最高。在失效模式中，观察到粘合失效主要发生在用软椅边补衬材料重新衬里的打印义齿基托材料中，而在铣削和注射义齿基托组中发现了内聚和混合失效模式。

结论

打印义齿基托的拉伸粘合强度值明显低于 PermaSoft、Tokuyama Rebase ii 和 ProBase Cold 义齿衬里的注射和铣削义齿基托，而铣削义齿基托在所有椅旁衬垫组中表现出最高的拉伸粘合强度值。此外，与硬衬垫材料相比，无论义齿基托类型（注射、打印和铣削）的义齿加工方法如何，软椅边衬垫材料的拉伸粘合强度值最低。