, Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey.
Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey.
J Mech Behav Biomed Mater. 2023 Jun;142:105804. doi: 10.1016/j.jmbbm.2023.105804. Epub 2023 Apr 5.
This in vitro study aims to evaluate the bonding strengths of Polyether ether ketone (PEEK), Polyether ketone (PEKK), Fiber, and Zirconia (ZrO) post-core restorations with posts in different diameter and length following chewing simulator.
Endodontic treatment was performed on 256 intact maxillary central teeth. The test specimens were prepared in four groups according to the types of materials: Glass fiber post-composite core (FB-n:64), Zirconia post-core (Zr-n:64), PEEK post-core (PE-n:64), and PEKK post-core (PK-n:64). The groups were divided into four subgroups according to diameter and length (n:16): Group 1: 10 mm length 1.75 mm diameter, Group 2: 10 mm length 1.5 mm diameter, Group 3: 7 mm length 1.75 mm diameter, Group 4: 7 mm length 1.5 mm diameter. Custom PEKK, PEEK, Zirconia post-cores, and Zirconia crowns were milled on the CAD/CAM. The post-cores and crowns were cemented to the teeth with dual-cure resin cement. After that, all subgroups were divided into control and cyclic loading groups. During the cycling, the control test group was kept in distilled water at 37±1C before the push-out test. Half of the specimens were loaded with 250,000 cycles and 50 N with a chewing simulator. All test specimens had 1.5 mm sections taken from their roots. Then, the push-out test was applied to these sections for bond strength. Data were analyzed by Mann-Whitney U test, Shapiro-Wilk, Kruskal-Wallis's test, and Chi-Square. The statistical significance level was determined as 0.05.
The bond strength of all test groups decreased after the cycling loading. The bond strength values of zirconia posts showed a statistically significant difference (p < 0.05). The 10 mm length 1.75 mm diameter posts made of Zirconium had the highest bond strength observed in all control and cyclic loading groups of test specimens (9.74 MPa-6.25 MPa). The PEEK test specimens with a 7 mm length and 1.75 mm diameter showed the weakest bond strength in all control and cyclic loading groups (5.44 MPa-3.37 MPa). The average of the cervical region's bond strength values was statistically significantly higher than the apical region (p < 0.05).
Within the limitations of this study, one-piece custom-milled Zirconia post-cores appear promising, as they perform well under functional forces, especially in the anterior region. In addition, custom-milled PEKK post-cores might be considered a suitable alternative to prefabricated fiber-reinforced posts.
本体外研究旨在通过咀嚼模拟器评估不同直径和长度的桩在不同类型材料（聚醚醚酮（PEEK）、聚醚酮（PEKK）、纤维和氧化锆（ZrO）后核修复体中的粘结强度。
对上颌中切牙进行牙髓治疗，共 256 颗完整的上颌中切牙。根据材料类型将测试标本分为四组：玻璃纤维桩-复合核（FB-n：64）、氧化锆桩核（Zr-n：64）、PEEK 桩核（PE-n：64）和 PEKK 桩核（PK-n：64）。根据直径和长度将每组分为四个亚组（n：16）：第 1 组：长度 10mm，直径 1.75mm；第 2 组：长度 10mm，直径 1.5mm；第 3 组：长度 7mm，直径 1.75mm；第 4 组：长度 7mm，直径 1.5mm。定制的 PEKK、PEEK、氧化锆桩核和氧化锆冠在 CAD/CAM 上铣削而成。用双固化树脂水门汀将桩核和牙冠粘接到牙齿上。之后，将所有亚组分为对照和循环加载组。在循环过程中，对照组在推拉力测试前将测试样本保存在 37±1°C 的蒸馏水中。一半的样本在咀嚼模拟器上加载 250,000 次和 50N 的循环载荷。从每个样本的根部取 1.5mm 段进行粘结强度测试。然后，对这些部位进行推拉力测试。数据采用曼-惠特尼 U 检验、Shapiro-Wilk、Kruskal-Wallis 检验和卡方检验进行分析。统计显著性水平定为 0.05。
所有测试组的粘结强度在循环加载后均降低。氧化锆桩的粘结强度值有统计学意义（p<0.05）。所有对照和循环加载组中，10mm 长、1.75mm 直径的氧化锆桩具有最高的粘结强度（9.74MPa-6.25MPa）。7mm 长、1.75mm 直径的 PEEK 测试样本在所有对照和循环加载组中的粘结强度最低（5.44MPa-3.37MPa）。颈部区域的粘结强度值平均明显高于根尖区域（p<0.05）。
在本研究的限制范围内，一体式定制铣削氧化锆桩核具有良好的功能性，表现出良好的效果，特别是在前牙区。此外，定制铣削的 PEKK 桩核可能是预制纤维增强桩的合适替代品。
