Photosensitization of Porphyromonas Gingivalis by KTP Laser and Methylene Blue

Çavuş O., ATALAY P., Torun Köse G., Korachi M., Şener B.

IADR General Session, Spain, 1 - 04 July 2010, pp.60

  • Publication Type: Conference Paper / Full Text
  • Country: Spain
  • Page Numbers: pp.60
  • Erciyes University Affiliated: Yes


At the present time photodynamic therapy (PDT) is receiving considerable interest for its potential as an antimicrobial therapy. Peri-implantitis is considered to be a multifactorial process involving bacterial contamination of the implant surface. Porphyromonas gingivalis, has been stated as one of the etiological agents of peri-implantitis. Previous studies have shown a variety of photosensitizers, including porphyrins, chlorophyll derivatives, phthalocyanines and azines to be effective in the photokilling of many Gram-positive and Gram-negative bacterial pathogens in addition to parasites, fungi, and viruses. Objective: the aim of this study was to evaluate the effects of a KTP (Potassium-titanyl-phosphate) laser (532nm) (Deka, Turkey) in vitro on P.gingivalis cultures with Methylene Blue (MB) as the photosensitizer. Method: KTP laser at different fluence parameters (between 10-100 J/cm²) and time points were applied to bacterial suspensions of 30 microliters (0,05% w/v MB) in 96 well-plates. Following laser radiation the samples were anaerobically incubated in an anaerobic cabinet (Don Whitley, UK) for 48 hours and the number of colony-forming units (CFU/ml) calculated. Results: Laser radiation with the presence of methylene blue showed total erradication of P.gingivalis at the optimal parameters of 56,81 J/cm² (30 seconds of laser radiation at 0,6W). Conclusion: the photoactivation of methylene blue with KTP laser radiation at 532nm has potential use as a biocidal mechanism for peri implantitis.