Int J Prosthodont. 2022 Mar-Apr;35(2):225-232. doi: 10.11607/ijp.7469.
The purpose of this exploratory in vitro study was to compare and evaluate the load-bearing capacity (LBC) of ceramic-veneered zirconia and composite-veneered polyetheretherketone (PEEK) three-unit fixed dental prostheses (FDPs) with and without thermocycling (TC).
The study included 40 samples of three-unit FDPs replacing mandibular first molars. The four groups included were: ceZIR (feldspathic ceramic-layered zirconia), ceZIR TC (feldspathic ceramic-layered thermocycled zirconia), cPEEK (composite-layered PEEK), and cPEEK TC (composite-layered thermocycled PEEK) (n = 10 per group). All frameworks were CAD/CAM milled. Ten PEEK and 10 zirconia samples were subjected to TC (6,000 cycles). All 40 FDP specimens were loaded by applying static load, using a universal testing machine. The maximum load required to fracture the specimens denoted the LBC. The comparison of LBC between the four groups was done by using two-way ANOVA with Tukey's post-hoc analysis (α = .05).
There was no statistically significant difference between LBC of cPEEK and ceZIR (P > .001) without thermal aging. LBC values decreased considerably for thermally aged specimens. Statistically significant differences were observed between LBC of cPEEK TC and ceZIR TC (P < .001), cPEEK TC and cPEEK (P < .001), and ceZIR TC and ceZIR (P = .001). On fracture analysis, cPEEK showed delamination failures whereas ceZIR displayed catastrophic connector fractures.
This comparative evaluation offers preliminary data highlighting substantial depreciation in the LBC of layered PEEK under simulated intraoral conditions, thus raising a question regarding the clinical longevity of layered PEEK multi-unit restorations. In contrast, feldspathic-layered zirconia can be suitable for use in posterior FDPs.
本探索性体外研究旨在比较和评估有/无热循环（TC）的陶瓷贴面氧化锆和复合贴面聚醚醚酮（PEEK）三单位固定义齿（FDP）的承载能力（LBC）。
本研究包括 40 个下颌第一磨牙缺失的三单位 FDP 样本。四个组分别为：ceZIR（长石陶瓷层氧化锆）、ceZIR TC（长石陶瓷层热循环氧化锆）、cPEEK（复合层 PEEK）和 cPEEK TC（复合层热循环 PEEK）（每组 10 个）。所有支架均通过 CAD/CAM 铣削而成。10 个 PEEK 和 10 个氧化锆样本进行 TC（6000 次循环）。所有 40 个 FDP 标本均通过万能试验机施加静态载荷进行加载。断裂标本所需的最大载荷表示 LBC。通过使用具有 Tukey 事后检验的双向方差分析（α=.05）比较四组间的 LBC。
无热老化时，cPEEK 的 LBC 与 ceZIR 之间无统计学差异（P >.001）。热老化后 LBC 值显著降低。cPEEK TC 与 ceZIR TC（P <.001）、cPEEK TC 与 cPEEK（P <.001）和 ceZIR TC 与 ceZIR（P =.001）之间观察到统计学显著差异。在断裂分析中，cPEEK 显示分层失效，而 ceZIR 显示灾难性连接体断裂。
这项比较评估提供了初步数据，突出了模拟口腔内条件下分层 PEEK 的 LBC 显著下降，从而对分层 PEEK 多单位修复体的临床耐久性提出了质疑。相比之下，长石陶瓷层氧化锆可适用于后牙 FDP。
