Flexural strength, surface roughness, and biofilm formation of ceramic-reinforced PEEK: An in vitro comparative study

Purpose This in vitro study aimed to compare flexural strength, surface roughness, and biofilm formation of ceramic-reinforced polyetheretherketone (PEEK) with conventionally heat-compressed and milled polymethylmethacrylate (PMMA) denture base materials.Materials and Methods Thirty strips (6.4 mm x 10 mm x 3 mm) and 30 discs (10 mm x 1 mm) were fabricated from a heat-compressed PMMA, milled PMMA, and ceramic-reinforced PEEK, 10 each. One surface of each sample was polished to mimic the laboratory procedure for denture base materials. Strips were then subjected to a three-point bend test using a universal testing machine at a crosshead speed of 5.0 mm/min. An optical profilometer was used to assess the Ra value (mm) of the discs on polished and unpolished sides. Biofilm formation behavior was analyzed by measuring the colony-forming unit (CFU)/mL of Candida albicans on the unpolished surface of the discs. One-way ANOVA followed by Tukey multiple comparison tests were used to compare the flexural strength, Ra value, and biofilm formation of the studied materials (a = 0.05).Results Ceramic-reinforced PEEK showed significantly higher flexural strength (178.2 +/- 3.2 MPa) than milled PMMA (89.6 +/- 0.8 MPa; p < 0.001) and heat-compressed PMMA (67.3 +/- 5.3 MPa; p < 0.001). Ceramic-reinforced PEEK exhibited a significantly higher Ra value than the other groups on unpolished sides; however, the polishing process significantly reduced the Ra values of all studied groups (p < 0.05). There was no significant difference in C. albicans adhesion among the groups (p < 0.05).Conclusion The flexural strength of tested materials was within acceptable limits for clinical use as a denture base material. Ceramic-reinforced PEEK had the highest surface roughness; however, its similarity in biofilm formation to other groups indicates its clinical acceptability as denture base material.

Automated summary

This in vitro study compared the flexural strength, surface roughness, and biofilm formation of ceramic-reinforced PEEK with conventionally heat-compressed and milled PMMA denture base materials. The results showed that ceramic-reinforced PEEK had significantly higher flexural strength and surface roughness compared to PMMA materials, but there was no significant difference in biofilm formation.