SILVIA CRISTINA NUNEZ

SILVIA CRISTINA NUNEZ

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Comparative study between photodynamic therapy and chemical solution on bacterial reduction in root canals
2004 - NUNEZ, S.C.; GOMES, L.; GARCEZ, A.S.; LAGE-MARQUES, J.L.
One of the major medical problems facing mankind in the next century will be the resistance of many pathogenic microbes to existing antibiotics. Oral bacteria can easily reach other body sites and also spread to other individuals. Therefore, antibiotic-resistant oral bacteria have the opportunity for rapid dissemination through the community and to transfer their resistance genes to other bacterial species. Photodynamic therapy involves the use of light-activated drugs which may offer an alternative approach to the use of traditional antimicrobial agents. The purpose of this study was to evaluate bacterial reduction in infected root canal. Thirty teeth with their root canals prepared were contaminated with Enterococcus faecalis. Control group was untreated. Chemical group was treated with sodium hypochlorite for 30 minutes and in the laser group, a photosensitizer paste was placed and maintained in the root canals for 5 minutes and irradiated with a diode laser, output power 10 mW and l= 685nm for 3 minutes. The bacterial reduction was significantly higher for laser group when compared to chemical and control groups. These results indicate photodynamic therapy as an effective method to kill E. faecalis.
Photodynamic action of toluidine blue in streptococcus mutans by fluorescence spectroscopy
2004 - NUNEZ, S.C.; GOMES, L.; GARCEZ, A.S.; MULLER, K.P.; JORGE, A.O.C.; RIBEIRO, M.S.
The antimicrobial activity of toluidine blue associated with red light has been demonstrated for a wide range of microorganisms including those commonly found in infected root canals, carious lesions and periodontal pockets. Recent reports have drawn attention to the problems of antimicrobial resistance and resistance of oral bacteria to antibiotics and local antiseptics is of increasing concern, thus photodynamic therapy could be an alternative antimicrobial approach to treat localized infections in oral cavity. In this study the fluorescence spectra of TB were obtained before and after laser exposure in the presence or absence of Streptococcus mutans. The dye concentration was 0.01%, the irradiation was performed with a diode laser, l= 660 nm, P= 40mW, exposure time of 3 minutes in a volume of 0.5 ml, with a pre-irradiation time (PIT) of one or five minutes. The results showed shifts in fluorescence spectra observed for different preirradiation times in the presence of S. mutans. In the absence of bacteria, a shift in the spectra was observed in the dye before and after irradiation. These findings may indicate a photobleaching of the dye denoting structural alterations after irradiation and confirm the importance of the PIT for the success of this therapy.
Comparation between photodynamic therapy and a bactericidal solution in the treatment of dental alveolitis microbiological evaluation
2004 - HAYEK, R.R.A.; YAMADA JUNIOR, A.M.; GARCEZ, A.S.; NUNEZ, S.C.; SUZUKI, L.C.; RIBEIRO, M.S.
Photodynamic therapy is a new therapeutic modality to treat microbial infections. The aim of this pilot study was to compare this new therapeutic approach with clorhexidine in mini pigs induced alveolitis. Alveolitis is an inflammatory disease that involves the superficial bone layer in the dental alveolus. Eight dental elements were extracted from mini pigs and immediately after the alveolus were contaminated with Streptoccocus aureus. After seven days the area presented edema and hyperemia. In the clorhexidine group the alveolus were debrided and irrigated with a 0.12% solution of clorhexidine. In Laser group the alveolus were debrided and photodynamic therapy was performed consisting in the application of a azulene paste inside the alveolus with a preirradiation time of 5 minutes followed by irradiation with a low power diode laser, ?= 685 nm, P= 50 mW, E= 9 J, for 3 minutes. Microbiological samples were harvested before and after treatment for both groups with sterile paper points. The results showed bacterial reduction in both groups, although photodynamic therapy was significantly more effective to reduce the population of S. aureus. This finding indicates that photodynamic therapy can be an alternative method to the treatment of alveolitis.
Exploring the effects of low-level laser therapy on fibroblasts and tumor cells following gamma radiation exposure
2016 - SILVA, CAMILA R.; CABRAL, FERNANDA V.; CAMARGO, CLAUDINEI F.M. de; NUNEZ, SILVIA C.; YOSHIMURA, TANIA M.; LUNA, ARTHUR C. de L.; MARIA, DURVANEI A.; RIBEIRO, MARTHA S.
Ionizing radiation (IR) induces DNA damage and low-level laser therapy (LLLT) has been investigated to prevent or repair detrimental outcomes resulting from IR exposure. Few in vitro studies, however, explore the biological mechanisms underlying those LLLT benefits. Thus, in this work, fibroblasts and tumor cells are submitted to IR with doses of 2.5 Gy and 10 Gy. After twenty-four-h, the cells are exposed to LLLT with fluences of 30 J cm–2, 90 J cm–2, and 150 J cm–2. Cellular viability, cell cycle phases, cell proliferation index and senescence are evaluated on days 1 and 4 after LLLT irradiation. For fibroblasts, LLLT promotes – in a fluence-dependent manner – increments in cell viability and proliferation, while a reduction in the senescence was observed. Regarding tumor cells, no influences of LLLT on cell viability are noticed. Whereas LLLT enhances cell populations in S and G2/M cell cycle phases for both cellular lines, a decrease in proliferation and increase in senescence was verified only for tumor cells. Putting together, the results suggest that fibroblasts and tumor cells present different responses to LLLT following exposure to gamma-radiation, and these promising results should stimulate further investigations. Senescence of tumor cells and fibroblasts on the 4th day after ionizing radiation (IR) and low-level laser therapy (LLLT) exposures. The number of senescent cells increased significantly for tumor cells (a) while for fibroblasts no increment was observed (b). The blue collor indicates senescence activity.
Dentin hypersensitivity clinical study comparing LILT and LEDT keeping the same irradiation parameters
2010 - LIZARELLI, R.F.Z.; MIGUEL, F.A.C.; PONTES, K.M.F.; VILLA, G.E.P.; NUNEZ, S.C.; BAGNATO, V.S.
Light therapy modulates serotonin levels and blood flow in women with headache. A preliminary study
2016 - MAGALHAES, MIRIAM T. de; NUNEZ, SILVIA C.; KATO, ILKA T.; RIBEIRO, MARTHA S.
Exploring light-based technology for wound healing and appliance distribution
2015 - RIBEIRO, MARTHA S.; NUNEZ, SILVIA C.; SABINO, CAETANO P.; YOSHIMURA, TANIA M.; SILVA, CAMILA R.; NOGUEIRA, GESSE E.C.; SUZUKI, HIDEO; GARCEZ, AGUINALDO S.
Morphological evaluation of Candida albicans after phododynamic therapy
2015 - BAPTISTA, ALESSANDRA; NUNEZ, SILVIA C.; SABINO, CAETANO P.; MIYAKAWA, WALTER; RIBEIRO, MARTHA S.
Morphological evaluation of Candida albicans after phododynamic therapy
2015 - BAPTISTA, ALESSANDRA; NUNEZ, SILVIA C.; SABINO, CAETANO P.; MIYAKAWA, WALTER; RIBEIRO, MARTHA S.
PDT in oral diseases of microbial origin: The challenge of oral biofilm
2015 - NUNEZ, SILVIA C.