Augmentation of Candida albicans Adhesion to Denture Materials Influenced By Surface Topography and Tobacco Components

Denture stomatitis, a common oral disease, can induce pathologic changes to the denture-bearing tissues. These tissue changes can vary from localized hyperemia to diffused erythema to papillary hyperplasia [1,2]. Patients with severe denture stomatitis may experience pain, itching, and/or burning sensation [3-5]. Studies have shown that the prevalence of denture stomatitis in the edentulous population ranges from 15% to over 70% with more cases found in the elderly, women, smokers, and immunocompromised [6-12]. Candida albicans adherence and colonization of denture prostheses has been shown to induce denture stomatitis [13,14]. In general, C.albicans species exist as commensal organisms in about 33% of the adult dentate patients and about 75% of the complete denture patients. Smears obtained from the intaglio surface of dentures often demonstrate the presence of the invasive filamentous hyphal form [8-17]. Denture base resins are susceptible to fungal colonization in the oral environment. Surface roughness is one of the factors that aids in the initial fungal attachment. Surface defects such as scratches, cracks, and porosities serve as protective surfaces for microorganisms to bind [18,19]. One of the more common denture resins used today is polymethylmethacrylate (PMMA), a polymer developed in the 1930s [20]. PMMA can be classified as heat-activated or chemically-activated resin based on the method of polymerization. Heat-activated PMMA can be processed by compression-molded, injection-molded, or microwaveprocessed techniques [21]. Physical characteristics of PMMA are dependent on the type of resin as well as the processing technique. Manufacturers of the injection-molded resin claim that the “cross-linked, high impact thomopolymer” obtained after polymerization offers excellent polishability and helps reduce plaque build-up [22]. It has been reported that use of tobacco products induces fungal denture stomatitis in susceptible patients [23]. According to a study by Arendorf et al. there are higher numbers of Candida in tobacco smokers as compared to non-smokers [24]. Salivary nicotine and cotinine are widely used in clinical and epidemiological smoking studies [25]. Nicotine is a weak base with a pKa value that approaches 8. When salivary pH increases, the non-ionized form of nicotine is absorbed across the buccal and nasal membranes [26]. Cotinine, the major metabolite of nicotine, has been reported to have a pKa of 5 [27]. The concentration of cotinine in saliva is variable depending on an individual’s nicotine metabolism and the salivary pH. Salivary concentrations of nicotine and cotinine can be affected by many factors such as cigarette brand, length of cigarette, gender, puffing behavior, and testing methods [28]. Robson et al. [29] reported that salivary nicotine concentrations ranged from 0.36μg/ml to Volume 9 Issue 2 2018