| 3015 In Vitro Photodynamic Eradication of Periopathogens Using the Periowave™ System | ||
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C. STREET1, L. PEDIGO2, and N. LOEBEL1, 1Ondine Biopharma Corporation, Redmond, WA, USA, 2Bioresearch Laboratories, Redmond, WA, USA OBJECTIVES: Photodynamic Disinfection (PDD) has been shown to be an effective antibacterial approach in vitro. This study evaluated the in vitro efficacy of the methylene blue based Periowave™ PDD system in eradication of the common periopathogens Porphyromonas gingivalis, Fusobacterium nucleatum, and Actinobacillus actinomycetemcomitans in both planktonic and biofilm cultures. The study also addressed changes in energy dose parameters in PDD-mediated eradication of these bacterial cultures. METHODS: Planktonic and biofilm cultures of the three periopathogens were exposed to a formulation comprising 0.01% methylene blue as the active ingredient and irradiated with a 670 nm non-thermal diode laser. Energy doses to the sample were varied from 1.5-6.0 Joules by adjustment of illumination time. Controls consisted of no treatment, light only, and photosensitizer only. Thermocouples were used to measure temperature changes in experimental samples during illumination. RESULTS: Results demonstrated that PDD using a total energy dose of 6 Joules was effective in eradicating P. gingivalis, F. nucleatum, and A. actinomycetemcomitans in both biofilm and planktonic cultures. Reductions in viable bacterial count from control at this energy dose were >4log10 (P. gingivalis and F. nucleatum) and >2log10 (A. actinomycetemcomitans). This amounts to >99.99% eradication of P. gingivalis and F. nucleatum and >99% reduction in A. actinomycetemcomitans. In general, decreasing the energy dose produced a dose-dependent killing effect in both culture systems. Changes in sample temperature did not exceed 3°C under these exposure parameters. CONCLUSIONS: Results of this study showed that three important periopathogens are susceptible to PDD-mediated killing, regardless of whether they are present in planktonic or biofilm form. Furthermore, this killing was subject to a light-dose dependency that should to be taken into account when determining optimal treatment times in clinical application. This study demonstrates that Periowave™ effectively eradicates the pathogens associated with chronic periodontitis. | ||
| Seq #254 - Late Breaking News - Posters 3:30 PM-4:45 PM, Thursday, March 22, 2007 Ernest N. Morial Convention Center Exhibit Hall I2-J | ||
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