Fracture resistance of custom-milled CAD/CAM post and core using two different materials: an in vitro study

Abstract

Introduction: Restoration of endodontically treated teeth could be challenging for dentists, as these teeth would be biomechanically compromised at multiple levels, such as tissue components and tooth structures.Objectives: This study aimed to evaluate fracture resistance and failure modes of teeth restored with custommilled posts and cores fabricated from polyetherketoneketone, fiber-reinforced resin materials, and prefabricated fiber posts. Material and methods: Thirty mandibular premolars were used in the present study. After endodontic treatment, teeth were randomly assigned into three groups, i.e., MPP: restored with custom-milled posts and cores fabricated from polyetherketoneketone (PEKK); MFP: restored with custom-milled posts and cores fabricated from fiber-reinforced resin; and PFP: restored with prefabricated fiber-reinforced resin posts, then all samples were restored with metal crowns. Samples were subjected to a 45 o shear force at the inner slope of buccal cusp to failure. One-way ANOVA for independent groups and χ 2 test at 0.05 statistical significance were applied. Results: Differences between fracture resistance means of the three groups were not statistically significant (p = 0.279 > 0.05). The fracture resistance means for the MPP group was 423.2 ± 113.28 N; 356.90 ± 141.050 N for the MFP group; and 439.5 ± 100.616 N for the PFP group. As for failure types, no significant difference among the three groups was detected (p = 0.366 > 0.05). Regarding the failure modes, the reparable failure modes in each group, i.e., MPP, MFP, and PFP were 60%, 80%, and 50%, respectively. Conclusions: Teeth restored with custom-milled posts and cores fabricated from PEKK and fiber-reinforced composite displayed an acceptable performance. Consequently, within the limitations of this study, these posts may be considered a good alternative to prefabricated fiber-reinforced posts.

Clinical performance of custom‐milled polyetherketoneketone (PEKK) posts and cores: A 12‐month follow‐up randomized controlled pilot study

“…This study showed no difference in fracture resistance. Furthermore, the failure mode in the PEKK group was favorable compared to the PFPs (Ghanem et al, 2022 ).…”

Metal-Free Alternative “Revolutionary PEKK”: An Emerging Material for Removable and Fixed Prosthesis Usage in Dentistry: A Critical Review

“…PEKK's elastic modulus is comparable to bones. There are certain following properties unique to PEKK: High impact resistance, tensile and compressive strength, and stiffness [21] , Substantial breakdown voltage [14,15] , Exceptional barrier qualities (CO2, H2S) [14][15][16] , Outstanding wear-rate and COF control (coefficient of friction), Excellent combustion resistance features, including being naturally flame-resistant and producing little smoke, minimal smoke toxicity. [17] Biological properties of PEKK: As a prospective replacement for titanium in long-term orthopedic applications, PEKK has high biocompatibility.…”

“…Walsh WR et al [14] has tried coating PEEK with titanium as the physical property of PEEK is maintained but the surface interface would react preferably to the host. [15] But the PEEK coated with titanium has reduced bond strength which leads to failure as it causes wear debris. That is why the PEKK is considered superior to these biomaterials.…”