Influence of Candida albicans biofilm coverage area on denture disinfection by microwave energy

Author(s)

Plinio Mendes Senna

• Document type: Master's Dissertation
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2010-11-06

Examining board members

Altair Antoninha Del Bel Cury; Helio Rodrigues Sampaio Filho; Renata Cunha Matheus Rodrigues Garcia

• Advisor: Altair Antoninha Del Bel Cury

Abstract

Oral candidosis is the most common fungal infection diagnosed in humans. In subjects with compromised immune system, it can disseminate to candidemia, which is related to high mortality and more hospital time consumption. Candidosis is commonly related to denture wearers, characterized by an inflammation of the coverage portion of mucosa, demanding the necessity of microbiologic control of the biofilm accumulated on denture surface for prevention of oral candidosis. Therefore, the aim of this study was to evaluate the influence of Candida albicans biofilm coverage area on the effectiveness of microwave disinfection. One hundred twenty sterile dentures have two distinct areas, 2.35 or 5.50cm2, coverage by 72 hours Candida albicans biofilm. Each denture was immersed in 200 mL of sterile distilled water and was irradiated by 450, 630 or 900 W and different exposure times (1, 2 e 3 min) until no viable cells were detected (n=6). The final temperature was also measured to verify its influence on this process. The results showed statistical difference between the biofilm coverage area (p<0,001), in which a higher coverage demands more exposure time for sterilization. The dentures with higher biofilm coverage and irradiated for 3 minutes, independently of power set, showed no fungal growth, this exposure time was statistically different from 1 and 2 min (p<0,001). Dentures with lower biofilm coverage were sterilized after 1 min at 900 W and 2 min for 450 and 630 W. There was a positive correlation between the final water temperature and the effectiveness of sterilization (r=0, 6170). Considering the limitations of this study, it is possible to conclude that lower biofilm coverage demands a lower microwave exposure time for sterilization achievement. (AU)

• FAPESP's process: 07/06482-6 - Microwave disinfection of removable dentures: Effectiveness and effects on acrylic resin.
• Grantee: Plinio Mendes Senna
• Support Opportunities: Scholarships in Brazil - Master