Effect of antimicrobial photodynamic therapy with Chlorella and Curcuma extract on Streptococcus mutans biofilms.

BACKGROUND: Antimicrobial photodynamic therapy (aPDT) using natural photosensitive agents is an effective method for preventing oral diseases of bacterial origin. The purpose of this study was to evaluate the antimicrobial effect of aPDT, using powdered extracts of Chlorella and Curcuma, on the biofilms of Streptococcus mutans (S. mutans), a bacterium that is known to cause dental caries. METHODS: Commercially available powdered Chlorella and Curcuma extracts were used as photosensitizers. S. mutans, cultured for 2 days, was inoculated (0.1 ml; 1 × 109 CFU/ml) on the surface of a hydroxyapatite (HA) disc and incubated for 24 h to allow the formation of a biofilm. The HA disc with the S. mutans biofilm was immersed in either Curcuma extract (0.5 mg/ml), Chlorella extract, distilled water (negative control), or Listerine (positive control) for 1 min and then irradiated with an LED (Qraycam; wavelength, 405 nm; energy, 59 mW) for 5 min. RESULTS: The application of aPDT with Curcuma or Chlorella extract to S. mutans 24-hour biofilms significantly decreased the number of viable cells and the live/dead cell ratio when compared with those in the negative control (distilled water; p < 0.05). CONCLUSIONS: aPDT using 405 nm light and Chlorella or Curcuma as a photosensitizer has significant antimicrobial effects against S. mutans biofilms. Thus, employing aPDT with natural plant extracts as photosensitizers could be an effective strategy for preventing dental caries but needs to be evaluated in properly controlled clinical trials..

Association of Work Patterns and Periodontitis Prevalence in Korean Adults Aged 50 Years or Older: A Nationwide Representative Study.

This study analyzed the relationship between the work pattern and the prevalence of periodontitis. We analyzed the data of 3320 adults (1779 men, 1543 women) aged 51-80 years from the Korean National Health and Nutrition Examination Survey (2013-2015). The work pattern was divided into two groups (regular and irregular). The periodontal status was assessed using the community periodontal index. We observed a statistically significant difference in the association between work patterns and prevalence of periodontitis in Korean women aged over 50 years. For female workers with irregular work patterns, the prevalence of periodontitis was lower than that in workers with regular work patterns by 10.3% (40.3% vs. 30.0%, p = 0.011). The annual health examination rate was significantly higher in the irregular group than in the regular group (for men 77.9% vs. 73.5%; p < 0.001, for women 76.4% vs. 75.9%; p < 0.001). In female workers with irregular work patterns, the annual dental examination rate was significantly higher than that in workers with a regular work pattern by 7.7% (34.3% vs. 26.6%, p = 0.043). In conclusion we found a statistically significant difference between the work patterns and prevalence of periodontitis in Korean women aged over 50 years.