Philippe Courtois

*Université Libre de Bruxelles, Brussels Belgium* 

### **1. Introduction**

474 Biomaterials – Physics and Chemistry

Wollin, T. A., C. Tieszer, et al. (1998). "Bacterial biofilm formation, encrustation, and

Zupkas, P., C. L. Parsons, et al. (2000). "Pentosanpolysulfate coating of silicone reduces

101-111.

encrustation." J Endourol 14(6): 483-488.

antibiotic adsorption to ureteral stents indwelling in humans." J Endourol 12(2):

Biological as well as inert surfaces of the oral cavity are exposed to an abundant microflora that is able to initiate the formation of biofilms. Yeasts are frequently involved, such as *Candida* (especially *albicans*), a low-level commensal of oral, gastrointestinal, and genitourinary mucosae in humans. *In vivo* and *in vitro* studies have shown *Candida* incorporation into biofilms covering different biomaterials used in the oral cavity for the manufacturing of dentures, orthodontic appliances, etc. Yeast (*Candida* genus) biofilms can then induce device-related infections mainly in the elderly and in medically-compromised patients with subsequent morbidity and occasional mortality, all bearing high social and financial costs. Generally, scientific literature does not integrate all aspects of material/tissue interfaces: mechanisms of *Candida* biofilm development and biomaterial maintenance, the welfare of patients, and prevention of candidosis. *In vitro* investigations were mainly undertaken with mono-species biofilms whereas *Candida* incorporation into biofilms on oral surfaces tends to correspond with an increase in the yeast/bacteria ratio. This illustrates the need for interdisciplinary insight. This chapter will review 1) the literature data concerning material surfaces in support of *Candida* biofilms in the oral environment, 2) the *in vitro* approaches to understanding the mechanisms of *Candida* biofilm formation on materials, 3) the interfaced manipulations in order to prevent *Candida* biofilm onset, and 4) the precautions when testing new devices *in vivo* in the oral cavity.
