Antifungal effect of tissue conditioners containing poly(acryloyloxyethyltrimethyl ammonium chloride)-grafted chitosan on Candida albicans growth in vitro

Abstract

Background/purpose Denture stomatitis is a pathological condition affecting the mucosa underneath ill-fitting dentures, and Candida albicans is considered its main etiologic factor. Tissue conditioners are temporary lining materials often applied to dentures to treat inflamed tissues. However, tissue conditioners do not exert antifungal activity, and the soft surface texture harbors C. albicans easily. The aim of this study was to examine the antifungal activity of tissue conditioners modified with chitosan (CS) or a quaternized chitosan (QCS), which was synthesized by grafting 2-[(acryloyloxy)ethyl] trimethyl ammonium chloride onto CS. Materials and methods Tissue conditioners containing varying weight percentages of CS or QCS were prepared as experimental discs 10 mm in diameter and 1 mm in thickness. Samples were co-cultured with C. albicans and the number of colony forming units was recorded. Other evaluations included cell toxicity and tensile bond strength to the resin denture base. Results It was found significantly fewer fungal colonies in tissue conditioners modified with CS or QCS, and none when the weight percentage of QCS exceeded 5%. CS and QCS did not affect the viability of human gingival epithelium cells or fibroblasts, and tensile bond strength did not differ between control and modified tissue conditioners. Conclusion This study provides a foundation for the development of QCS as a novel and safe antifungal agent applied to tissue conditioners in clinical practice.

Mechanical and Surface Properties of Resilient Denture Liners Modified with Chitosan Salts

“…In vitro studies testing other material properties such as bonding properties to base materials, sorption, solubility, etc., and especially antifungal tests should follow up to further investigate the properties of CS salts when mixed into resilient denture liners. In the case of antimicrobial properties, positive results have been reported for nano-chitosan particles in light-cured resins [65] as well as CS and CS oligosaccharides [40], CS nanoparticles [42] and CS and quaternized CS in tissue conditioners [41]. In contrast, modification of hard denture base materials by adding CS-HCl or CS-G showed unsatisfactory antifungal/antibiofilm activity (own unpublished data).…”

“…Modifications of tissue conditioners with CS, CS nanoparticles, quaternized CS and CS-oligosaccharide are described [40,41,42]. These studies show promising antifungal activity of modified materials but do not evaluate mechanical properties.…”

Applying the Host-Microbe Damage Response Framework to Candida Pathogenesis: Current and Prospective Strategies to Reduce Damage

“…Another strategy to overcome fungal overgrowth during DS is to inhibit adherence of the organisms on denture base materials by countering the hydrophobic properties of acrylic resins that promote C. albicans adhesion and colonization [130,131]. Accordingly, hydrophilic coating materials [132] and polysaccharides, namely mannans and chitosan [133][134][135], have been shown to inhibit fungal adhesion to acrylic denture materials. Yet another anti-biofilm strategy being explored is photodynamic inactivation (PDI) therapy.…”

Effect of zinc oxide nanoparticles incorporated into tissue conditioner on antifungal, physical, and mechanical properties

“…A previous study investigated the effect of incorporating inorganic antimicrobial agents, such as silver nanoparticles, into tissue conditioners 18) . Organic or natural agents, such as origanum oil and poly (acryloyloxyethyltrimethyl ammonium chloride)-grafted chitosan, have been mixed with tissue conditioners 19,20) . However, the incorporation of such antimicrobial agents alters the physical or mechanical properties of tissue conditioners 21,22) .…”