Comparison of the fracture strength of endodontically treated teeth restored with polyether ether ketone, zirconia and glass‐fibre post‐core systems

Abstract

Purpose This study aimed to compare the fracture resistance and fracture mode of maxillary central incisors restored with four different sizes and three different post‐core systems. Materials and methods One hundred and twenty maxillary incisors were endodontically treated and randomly divided into three groups (12 subgroups). Post cavities for the narrow subgroups were prepared with 1.4‐mm‐diameter drills in lengths of 7.5 mm (SN) and 10 mm (LN). Post cavities for the wide subgroups were prepared with 1.6‐mm‐diameter drills in lengths of 7.5 mm (SW) and 10 mm (LW) (n = 10). Group F was restored with glass‐fibre post and composite resin core, Group P was restored with custom PEEK post‐core and Group Z was restored with custom zirconia post‐core. All posts were cemented with a dual‐cure resin cement. Zirconia copings were cemented. Specimens were loaded on the palatal surface with a universal testing machine, and the fracture strengths of the teeth were statistically analysed using ANOVA and post hoc Tukey tests. Results Statistically significant differences existed between the fracture strengths of the post materials. The highest fracture strength was in Group F, and the lowest was in Group P. Evaluation of the fracture strengths of the post lengths and diameters demonstrated that the short‐narrow group of Group Z had the lowest fracture strength (P < .05). The long‐wide group of Group F showed the highest fracture resistance. In Group P, no statistically significant difference existed between the post‐cores of different dimensions (P > .05). Irreparable fractures were observed mostly in Group Z, and decementation was more common in Group P. Conclusions PEEK post‐cores showed sufficient fracture strength for the anterior region, similar to the other two post‐core materials. PEEK post‐cores showed more decementation and repairable fractures at lower forces, while restoration failure was mostly catastrophic for glass‐fibre and zirconia posts.

Fracture resistance of endodontically treated teeth, restored with two post-core systems in different post space diameters (in vitro study)

“…A sample size was calculated using a sample size calculation program(G*Power version 3.1.9.2, Department of Biomedical Informatics and Medical Statistics, Medical Research Institute, University of Alexandria, Egypt.) [ 22 ] where α = 0.05 and power of 80% and the mean and standard deviation were taken from a previous study [ 23 ]. At least 5 samples were assigned for each group; this minimal sample size calculation was done depending on a previous study [ 23 ], the number of groups in this research is 4, so the total sample size is 20 specimens.…”

PEEK in Fixed Dental Prostheses: Application and Adhesion Improvement

“…Özarslan et al reported maximum fracture resistance in glass fiber posts, followed by zirconia posts and PEEK posts, and the fracture load of PEEK posts displayed no significant difference when restored with different size root canals [10]. Most failures of PEEK posts resulted from the decementation of post and core and were repairable [10,69]. Sugano et al tested PEEK in flared root canals in a bovine tooth model but found that PEEK posts showed poor mechanical performance in comparison to glass fiber posts in the restoration of flared root canals [70].…”

“…PEEK posts exhibited a significantly lower fracture load than nickel-chromium (NiCr) alloy posts while presenting similar fracture resistance to nano-ceramic composites posts and fiberglass posts [69]. Özarslan et al reported maximum fracture resistance in glass fiber posts, followed by zirconia posts and PEEK posts, and the fracture load of PEEK posts displayed no significant difference when restored with different size root canals [10]. Most failures of PEEK posts resulted from the decementation of post and core and were repairable [10,69].…”

“…PEEK exhibits excellent mechanical properties, including a low Young's modulus (3 to 4 GPa), which, compared to metal alloys (110 to 130 GPa), is closer to that of human cortical bone (14 GPa) [8]. Given its deformability, PEEK can provide more balanced stress distribution, limiting stress-shielding when serving as an implant [9] and lowering the risk of root fracture when used for post-and-core restoration [10]. However, when compared…”

Application of CAD/CAM technologies and materials for prosthetic restoration of severely damaged teeth—clinical cases

“…Metal alloys, ceramics based on zirconium dioxide, lithium disilicate ceramics, fibre‐reinforced composites, PEEK, nano‐ceramic resin composites, hybrid ceramics etc. can be processed by milling 11–13 …”