Denture Plaque and Adherence of Candida Albicans To Denture-Base Materials in Vivo and in Vitro

Abstract

The aim of this paper is to review our understanding of the mechanisms and clinical significance of adhesion of C. albicans to denture-base materials in relation to denture plaque and denture-related stomatitis. Earlier reports in the literature of a 65% prevalence level of denture-related stomatitis seem to be exaggerated. More recent studies indicate that denture-related stomatitis is considerably less common, particularly in normal healthy subjects. The etiology of the condition is discussed in this review, and although much of the literature supports the view that the condition is strongly associated with C. albicans, this is not always so. In some subjects, the cause appears to be related to a non-specific plaque. This review also considers the role of denture plaque in the pathogenesis of denture-related stomatitis, the sequential development of denture plaque, and its colonization by Candida organisms. Designing controlled in vivo studies is difficult, and as a consequence, many investigators have had to resort to in vitro studies. The majority of these studies have attempted to investigate the hydrophobicity of C. albicans, relating the surface free-energy of denture-base materials, particularly acrylic resin, to that of the organism. Surprisingly little work has been directed at surface roughness and how it affects retention of organisms. Further, no attention has been paid to the properties and character of the surface, other than average surface roughness, as it affects adhesion. A comparison of results from in vitro studies on the effect on adhesion of pre-coating the surfaces of denture-base materials with saliva has produced equivocal conclusions. This is largely due to little standardization of experimental protocols between studies, particularly in the collection and handling of the saliva used. In conclusion, the review strongly supports the suggestion that adherence of C. albicans to denture-base materials in vitro is related to the hydrophobicity of the organism. The clinical significance of the observation and the mechanisms for the development and maturation of denture plaque are yet to be understood. There is a clear need for further investigation of other factors that may moderate the adhesion of organisms and subsequent colonization of denture-base materials.

Analysis of the in vitro adherence of Streptococcus mutans and Candida albicans

“…Previous studies demonstrate the benefits of microorganism interactions (4,8,16,29,30), although it is likely that antagonistic interactions also play an important role in mixed biofilm. In particular, the 48 h period was the most favorable to S. mutans (p-value=0.0078, Table 1).…”

“…In the case of dental biofilms, its role in coaggregation with S. mutans during the mechanisms of microbial adherence to the dental surface has been the focus of research (2,13,26,32,35). In addition, the adherence to acrylic prostheses has been often investigated (7,19,21,22,29,31).…”

Candida biofilm formation on voice prostheses

“…It has been suggested that the adhesion of bacteria to VPs is a prerequisite for subsequent colonization by yeasts (Neu et al, 1994a). Such a sequence in colonization has also been described for denture stomatitis (Radford et al, 1999). Millsap et al (2001) studied in vitro adhesion of yeasts suspended in saliva to silicone rubber with and without adhering bacteria.…”

Surface roughness influences Candida albicans biofilm formation on denture materials

“…Denture materials with rougher surfaces have been shown to exhibit higher yeast counts [7]. The higher porosity provides an increased chance of microbial retention and protection from the shear forces that arise during mechanical and chemical cleaning [9,10].…”

“…Candida albicans has been reported to play a major role in Candida-associated denture stomatitis (CADS) pathogenesis, and has been found on both poly(methyl methacrylate) (PMMA) acrylic resin and poly(ethyl methacrylate) (PEMA) liner materials [1][2][3][4][5][6][7]. For a successful colonization, C. albicans must first adhere to the denture surface [8] and the substratum characteristics, such as the surface roughness (SR), could influence this process.…”