Combination of 10% EDTA, Photosan, and a blue light hand-held photopolymerizer to inactivate leading oral bacteria in dentistry in vitro.

AIMS: The goal of this study was to investigate the phototoxicity of Photosan in combination with EDTA and a hand-held photopolymerizer used in dentistry for light-curing resins against leading key pathogens in caries, endodontic treatment failures, and periodontitis respectively.

METHODS AND

RESULTS

Cellular uptake of Photosan was detected by fluorescence spectroscopy for Streptococcus mutans and Enterococcus faecalis but not for Aggregatibacter actinomycetemcomitans. Addition of 10% EDTA enabled the uptake of Photosan by A. actinomycetemcomitans. Killing of S. mutans and E. faecalis mediated by Photosan and blue light was concentration and light dose dependent, achieving a >or=99.9% (>or=3 log(10) reduction) efficacy of bacteria killing. In the presence of 10% EDTA, Photosan induced a reduction of >or=4 log(10) in the viability of A. actinomycetemcomitans at a concentration of 50 microg ml(-1), upon activation at a dose of 9.65 J cm(-2) for 60 s. EDTA alone, light alone, and Photosan alone were not able to kill bacteria.

CONCLUSIONS

Ten per cent EDTA and Photosan cause a potent phototoxicity against oral bacteria upon illumination with a photopolymerizer.

SIGNIFICANCE AND IMPACT OF THE STUDY: Increasing antibiotic resistance and insufficient drug concentrations within the sulcus fluid are responsible for lacking antimicrobial efficacy. This study provides useful information that combination of Photosan, EDTA, and a photopolymerizer may be a potentially powerful tool for the efficient destroying of key oral bacteria.