Photosensitizer and light diffusion through dentin in photodynamic therapy

Nogueira, Ana Cláudia Fernandes; Graciano, Ariane Ximenes; Nagata, Juliana Yuri; Fujimaki, Mitsue; Terada, Raquel Sano Suga; Bento, A. C.; Astrath, N. G. C.; Baesso, Mauro Luciano

doi:10.1117/1.jbo.18.5.055004

Cited by 21 publications

(17 citation statements)

References 17 publications

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“…The optical absorption band of TB extended from 500 nm to 700 nm. The visible absorption maximum ( max ) of TB was 630 Ϯ 4 nm; max of TB were also observed at 570 nm and 650 nm (24). The optical absorption measurement of Ce6 revealed maximum absorption peaks at around 403 Ϯ 2 nm (Soret band) and 664 Ϯ 3 nm (Q band), respectively (25).…”

Section: Methodsmentioning

confidence: 95%

Novel Broad-Spectrum Antimicrobial Photoinactivation of In Situ Oral Biofilms by Visible Light plus Water-Filtered Infrared A

Karygianni

Ruf

Follo

et al. 2014

Appl Environ Microbiol

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Antimicrobial photodynamic therapy (APDT) has gained increased attention as an alternative treatment approach in various medical fields. However, the effect of APDT using visible light plus water-filtered infrared A (VIS ؉ wIRA) on oral biofilms remains unexplored. For this purpose, initial and mature oral biofilms were obtained in situ; six healthy subjects wore individual upper jaw acrylic devices with bovine enamel slabs attached to their proximal sites for 2 h or 3 days. The biofilms were incubated with 100 g ml ؊1 toluidine blue O (TB) or chlorin e6 (Ce6) and irradiated with VIS ؉ wIRA with an energy density of 200 mW cm ؊2 for 5 min. After cultivation, the CFU of half of the treated biofilm samples were quantified, whereas following live/dead staining, the other half of the samples were monitored by confocal laser scanning microscopy (CLSM). TB-and Ce6-mediated APDT yielded a significant decrease of up to 3.8 and 5.7 log 10 CFU for initial and mature oral biofilms, respectively. Quantification of the stained photoinactivated microorganisms confirmed these results. Overall, CLSM revealed the diffusion of the tested photosensitizers into the deepest biofilm layers after exposure to APDT. In particular, Ce6-aided APDT presented elevated permeability and higher effectiveness in eradicating 89.62% of biofilm bacteria compared to TB-aided APDT (82.25%) after 3 days. In conclusion, antimicrobial photoinactivation using VIS ؉ wIRA proved highly potent in eradicating oral biofilms. Since APDT excludes the development of microbial resistance, it could supplement the pharmaceutical treatment of periodontitis or peri-implantitis.

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Section: Methodsmentioning

confidence: 95%

Novel Broad-Spectrum Antimicrobial Photoinactivation of In Situ Oral Biofilms by Visible Light plus Water-Filtered Infrared A

Karygianni

Ruf

Follo

et al. 2014

Appl Environ Microbiol

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“…It has been shown that the penetration of toluidine blue and methylene blue in healthy dentin are, respectively, 130 and 190 µm, 26 and this penetration is even smaller in the carious dentin, only 52.6 µm below the surface. 27 Therefore, the altered structure of the carious dentin may not allow adequate penetration of the photosensitizer 28,14 and its interaction with microorganisms such as the ones in the mutans group, which have been observed in dental tubules at depths of 200 µm or more from the dentinal surface.…”

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confidence: 99%

Clinical effect of photodynamic therapy on primary carious dentin after partial caries removal

et al. 2016

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This study was conducted to assess the clinical effect of photodynamic therapy (PDT) in the decontamination of the deep dentin of deciduous molars submitted to partial removal of carious tissue. After cavity preparation, dentin samples were taken from the pulp wall of nineteen deciduous molars before and after PDT application. Remaining dentin was treated with 0.01% methylene blue dye followed by irradiation with an InGaAlP diode laser (λ -660 nm; 40 mW; 120 J/cm 2 ; 120 s). Dentin samples were microbiologically assessed for the enumeration of total microorganisms, Lactobacillus spp. and mutans streptococci. There was no significant difference in the number of colony-forming units (CFU) for any of the microorganisms assessed (p > 0.05). Photodynamic therapy, using 0.01% methylene blue dye at a dosimetry of 120 J/cm 2 would not be a viable clinical alternative to reduce bacterial contamination in deep dentin.

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“…Besides, this visual method of cross‐section samples is destructive, it lacks spatial resolution and it is time consuming . The photoacoustic spectroscopy (PAS) technique expressed by a semiquantitative model also has been proposed; however, the demineralized tissues were not taken into account during the analysis .…”

Section: Discussionmentioning

confidence: 99%

A Comparative Study of the Photosensitizer Penetration into Artificial Caries Lesions in Dentin Measured by the Confocal Raman Microscopy

Melo

Rolim

Zanin

et al. 2013

Photochem & Photobiology

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This study utilized the confocal Raman microspectroscopy (CRM) technique for the first time to investigate the degree of the penetration of toluidine blue-orto (TBO) in artificial caries lesions produced by two distinct caries-inducing models. The dentin specimens (n = 10) were divided into three groups: control, in vitro and in situ. Thereafter, the lesion depth and the demineralization level were evaluated by cross-sectional microhardness (CSMH). CRM mapping across the dentin surface was assessed after the dye application. The CSMH and CRM data were analyzed by t-test and ANOVA, respectively (P < 0.05). The values of the lesion depth and the demineralization areas were higher for in situ samples (P < 0.05). The TBO penetration values (μm) for the control, in vitro and in situ groups were 44.8 ± 5.6, 46.1 ± 4.5 and 51.2 ± 8.5, respectively. There were no statistically significant differences among the groups (P > 0.05). The rate of TBO penetration was detected up to about <50 μm and the demineralization level did not influence the results. These results have showed promising parameters to develop new protocols for deep caries lesions management using photodynamic antimicrobial chemotherapy.

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Photosensitizer and light diffusion through dentin in photodynamic therapy

Cited by 21 publications

References 17 publications

Novel Broad-Spectrum Antimicrobial Photoinactivation of In Situ Oral Biofilms by Visible Light plus Water-Filtered Infrared A

Novel Broad-Spectrum Antimicrobial Photoinactivation of In Situ Oral Biofilms by Visible Light plus Water-Filtered Infrared A

Clinical effect of photodynamic therapy on primary carious dentin after partial caries removal

A Comparative Study of the Photosensitizer Penetration into Artificial Caries Lesions in Dentin Measured by the Confocal Raman Microscopy

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