The Effect of Saliva on the Adhesion of Candida albicans to Prosthodontic Obturator Materials

Objectives: This study aimed to investigate the influence of saliva on the adhesion of C. albicans to various obturator prosthetic materials. Methods: This in vitro study investigated C. albicans adherence using clinical isolates, including one isolated from an obturator. The adherence of C. albicans cells to heat-cured acrylic, self-cured acrylic, a tissue conditioner, and silicone was measured using static and flow adhesion assays. The effect of pooled saliva from patients receiving radiotherapy or healthy volunteers on C. albicans adherence was determined. The adsorption of salivary proteins to acrylic coupons was investigated using SDS-polyacrylamide gel electrophoresis, Western blotting, and mass spectrometry. Results: It was found that C. albicans adhered to all obturator materials. Saliva was found to approximately double the adhesion of C. albicans to obturator materials, with saliva from patients who had received radiotherapy as part of their cancer treatment tending to increase adhesion more than saliva from healthy volunteers. The protein SPLUNC2 was found to be selectively concentrated by heat- and self-cured acrylic and may contribute to the adhesion of C. albicans to acrylic. Conclusions: This study found that saliva promotes the adhesion of C. albicans, and salivary proteins may play a role in facilitating this process. Adhesion was lower to acrylic-based prosthetic materials than to other materials. This suggests that interim obturators should be made from self-cured acrylic, and definitive obturators should be made from heat-cured acrylic.