Development of a Rat Model of Candida-Associated Denture Stomatitis

Objectives: Denture stomatitis (DS), caused by the opportunistic fungal pathogen Candida albicans, is an oral condition characterized by localized and general inflammation of the denture bearing mucosa. This condition, which affects up to 70% of denture wearers, stems from the ability of C. albicans to adhere to and form biofilms on dentures. Currently, there are no effective therapeutics for the prevention of this chronic and recurrent infection. The aim of this study was to engineer and fabricate an oral device and develop a rat model suitable for evaluating novel therapeutics against DS.
Methods: We utilized digital dental technologies to design and 3D print denture devices using a biocompatible dental resin. The fabricated devices were cemented to the cheek teeth using flowable composite in order to secure the devices on the palates of the rats. The devices featured a hole accessing the palate, through which C. albicans was applied to induce infection. The rats were euthanized 72-96 hours post-infection in order to monitor disease progression. Devices, associated palatal tissue, as well as tongues were recovered and assessed for microbial burden and processed for tissue histopathology analysis. Further, to visualize biofilm formation, devices were processed for electron-scanning microscopy (SEM).
Results: Results from tissue analysis demonstrated massive infection and tissue invasion by C. albicans whereas SEM imaging revealed mature biofilms composed of C. albicans hyphae and bacteria formed on the devices and tongues.
Conclusions: The combined findings from this study demonstrate the establishment of a feasible animal model that mimics clinical DS in humans. We plan to use this model to evaluate the efficacy of a novel antimicrobial oral formulation developed in our laboratories for the prevention of biofilm formation and development of DS.