<abstract xmlns="http://www.w3.org/1999/xhtml"><p>This study compared the outcome of photosensitization on the viability of four different cariogens in planktonic form as well as biofilms in human dentine. Photodynamic therapy was carried out with a gallium aluminium arsenide laser (670 nm wavelength) using Toluidine blue O (TBO) as the photosensitizer. Cariogenic bacteria (<italic>Streptococcus mutans</italic>, <italic>Lactobacillus casei</italic>, <italic>Streptococcus salivarius</italic> and <italic>Actinomyces viscosus</italic>) were exposed to TBO and then to the laser for 1 minute in planktonic suspension. Then, tooth slices previously incubated for 24 hours with broth cultures of broth culture of the four cariogenic organisms were exposed to antimicrobial photosensitization. The control samples consisted of planktonic and sessile cells that were exposed to TBO alone, laser alone and the bacterial cells that were not treated with TBO or laser. The results showed significant reductions in the viability of <italic>S. mutans</italic>, <italic>L. casei</italic> and <italic>A. viscosus</italic> in both planktonic form (to 13%, 30%, and 55%, respectively) and sessile form hosted in dentinal tubules (to 19%, 13% and 52%, respectively), relative to the controls. <italic>S. salivarius</italic> was the least affected in planktonic (94% viability) and sessile form (86% viability). In conclusion, sensitivity to photosensitization is species-dependent and sessile biofilm cells are affected to the same extent as their planktonic counterparts.</p></abstract>

This study compared the outcome of photosensitization on the viability of four different cariogens in planktonic form as well as biofilms in human dentine. Photodynamic therapy was carried out with a gallium aluminium arsenide laser (670 nm wavelength) using Toluidine blue O (TBO) as the photosensitizer. Cariogenic bacteria (Streptococcus mutans, Lactobacillus casei, Streptococcus salivarius and Actinomyces viscosus) were exposed to TBO and then to the laser for 1 minute in planktonic suspension. Then, tooth slices previously incubated for 24 hours with broth cultures of broth culture of the four cariogenic organisms were exposed to antimicrobial photosensitization. The control samples consisted of planktonic and sessile cells that were exposed to TBO alone, laser alone and the bacterial cells that were not treated with TBO or laser. The results showed significant reductions in the viability of S. mutans, L. casei and A. viscosus in both planktonic form (to 13%, 30%, and 55%, respectively) and sessile form hosted in dentinal tubules (to 19%, 13% and 52%, respectively), relative to the controls. S. salivarius was the least affected in planktonic (94% viability) and sessile form (86% viability). In conclusion, sensitivity to photosensitization is species-dependent and sessile biofilm cells are affected to the same extent as their planktonic counterparts.

Comparison of the Photosensitivity of Biofilms of Different Genera of Cariogenic Bacteria in Tooth Slices

Polish Journal of Microbiology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

This study compared the outcome of photosensitization on the viability of four different cariogens in planktonic form as well as biofilms in human dentine....

Comparison of the Photosensitivity of Biofilms of Different Genera of Cariogenic Bacteria in Tooth Slices

Article Category: original-paper

Published Online: Dec 10, 2018

Page range: 455 - 462

Received: May 07, 2018

Accepted: Jul 17, 2018

DOI: https://doi.org/10.21307/pjm-2018-053

Keywords
cariogenic bacteria, planktonic, sessile cells, tooth slice, photodynamic therapy

© 2018 Homa Darmani et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Fig. 1.

Fig. 2.

Fig. 3.

Fig. 4.

Comparison of the Photosensitivity of Biofilms of Different Genera of Cariogenic Bacteria in Tooth Slices

Article Category: original-paper

Published Online: Dec 10, 2018

Page range: 455 - 462

Received: May 07, 2018

Accepted: Jul 17, 2018

DOI: https://doi.org/10.21307/pjm-2018-053

Keywordscariogenic bacteria, planktonic, sessile cells, tooth slice, photodynamic therapy

© 2018 Homa Darmani et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Fig. 1.

Fig. 2.

Fig. 3.

Fig. 4.

Keywords
cariogenic bacteria, planktonic, sessile cells, tooth slice, photodynamic therapy