Use of PolyEtherEtherKetone (PEEK) containing the antifungal agent nonanoic acid as a denture base material to inhibit Candida albicans colonisation

Abstract

Introduction: Complete denture is one of the treatment modalities in treating edentulous patients. However, denture stomatitis is one of the critical complications of wearing a complete denture. Yet, the current materials used in fabricating denture bases are unsatisfactory due to mechanical drawbacks and their association with increased risk of denture stomatitis. Objective: To investigate the modification of the newly arising denture base material polyetheretherketone (PEEK) by sulfuric acid etching to act as a scaffold that retains the antifungal agent nonanoic acid in an attempt to inhibit the growth of the C. albicans and compare it to well- known miconazole antifungal drug. Moreover, to evaluate the surface property of acid-modified PEEK. Material and methods: Disc-shaped samples were prepared from PEEK. Sixteen samples were randomly selected for both plain (n=8) and etched (n=8) samples and surface property analysis performed. Fifteen etched discs allocated into five groups in triplicate experiments as follows: (PBS) as a negative control, miconazole as a positive control, and three different concentrations of nonanoic acid to perform a disc diffusion test to measure the ability of these antifungals in the inhibition of candida growth. Also, the XTT assay was used to measure the biofilm viability of C. albicans in the absence or presence of nonanoic acid. Results: Surface roughness was significantly higher on the etched PEEK compared to plain samples (P<0.0001), and the microhardness value of the etched PEEK was significantly lower than the plain disc (P<0.0001). The disc diffusion test significantly demonstrated a higher area of inhibition zone of the nonanoic acid with 0.2M compared to the other groups. Also, a dose- response relationship of nonanoic acid was found in killing candida. The XTT viability assay validates the antifungal effectiveness of nonanoic acid on the inhibition of the growth of the candida than does the miconazole group. Conclusions: Within the limitations of this study, the data suggest that nonanoic acid is an attractive alternative in inhibiting the growth of C. albicans compared to the well-known antifungal drug (miconazole). Moreover, the data demonstrate the dose-response relationship of nonanoic acid in inhibiting candida growth. Further studies are indispensable before utilizing the modified PEEK as a denture base material.