Statement of problem

Demand is increasing for polyetheretherketone (PEEK) as a fixed dental prosthesis core material. However, information is lacking about how the precision of these restorations is affected by the fabrication procedures.

Purpose

The purpose of this in vitro study was to evaluate the influence of different fabrication techniques on the marginal precision of PEEK single-crown copings.

Material and methods

A stainless-steel master die was designed to simulate a prepared mandibular second molar to receive ceramic crowns. Thirty PEEK copings were fabricated and divided into 3 groups (n=10) according to the fabrication technique: milled from a prefabricated PEEK blank by using a computer-aided design and computer-aided manufacturing (CAD-CAM) system (PC); pressed from prefabricated PEEK pellets (PP); and pressed from PEEK granules (PG); in addition, 3-mol yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) copings (n=10) were produced by using the same CAD-CAM system and served as a control. Marginal precision measurements (in μm) were recorded at 4 reference points on each coping by using a digital microscope. The data obtained were statistically analyzed by using 1-way ANOVA and the pair-wise Tukey (HSD) test to study the difference between group mean values (α=.05).

Results

The overall mean ±standard deviation marginal gap at the marginal opening for the copings was 78 ±10 μm for PEEK granules copings, 72 ±9 μm for PEEK pellet copings, 45 ±6 μm for PEEK CAD-CAM copings, and 43 ±1 μm for the 3Y-TZP CAD-CAM control. A statistically significant difference was found between the milled and pressed copings as indicated by the ANOVA test (P<.001). The pair-wise Tukey honestly significant difference (HSD) test showed a nonsignificant difference (P>.05) between milled 3Y-TZP and milled PEEK copings; moreover, no significant difference was observed between the PEEK copings pressed from pellets or granules (P>.05).

Conclusions

The marginal precision of PEEK CAD-CAM–fabricated copings showed significantly lower mean marginal gap values than PEEK pressed copings. The marginal gap mean values recorded were all within a clinically acceptable range (120 μm).

中文翻译：

---

不同制造工艺对聚醚醚酮单冠顶盖边缘精度的影响。

问题陈述

对聚醚醚酮（PEEK）作为固定义齿的核心材料的需求正在增加。但是，缺乏有关这些修复体的精度如何受到制造程序影响的信息。

目的

这项体外研究的目的是评估不同制造技术对PEEK单冠顶盖边缘精度的影响。

材料与方法

设计了一个不锈钢主模来模拟准备好的下颌第二磨牙，以容纳陶瓷牙冠。根据制造技术，制造了三十个PEEK顶盖，分为3组（n = 10）：通过使用计算机辅助设计和计算机辅助制造（CAD-CAM）系统（PC）从预制的PEEK毛坯中铣削；由预制PEEK颗粒（PP）压制而成；由PEEK颗粒（PG）压制而成；另外，通过使用相同的CAD-CAM系统制备3摩尔氧化钇稳定的四方氧化锆多晶（3Y-TZP）顶盖（n ＝ 10）并用作对照。使用数码显微镜在每个处理的4个参考点上记录边缘精度测量值（以μm为单位）。

结果

PEEK颗粒顶盖的边缘开口处的总体平均±标准偏差边缘间隙对于PEEK颗粒顶盖为78±10μm，对于PEEK颗粒顶盖为72±9μm，对于PEEK CAD-CAM顶盖为45±6μm和43±1μm用于3Y-TZP CAD-CAM控制。如ANOVA试验所示，在铣削和压制的顶盖之间发现了统计学上的显着差异（P <。001）。成对的Tukey诚实诚实显着性差异（HSD）测试显示，研磨的3Y-TZP和研磨的PEEK顶盖之间无显着性差异（P > .05）；此外，从颗粒或颗粒压制的PEEK顶盖之间没有观察到显着差异（P > .05）。

结论

PEEK CAD-CAM制成的顶盖的边缘精度显示出比PEEK压制顶盖的平均边际间隙值低得多。记录的边际间隙平均值均在临床可接受的范围内（120μm）。