AECIO MASSAYOSHI YAMADA JUNIOR

AECIO MASSAYOSHI YAMADA JUNIOR

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A case report of photodynamic therapy on bacterial reduction before immediate implant
2004 - SUZUKI, L.C.; YAMADA JUNIOR, A.M.; HAYEK, R.R.A.; RIBEIRO, M.S.
Recent studies have demonstrated that a number of oral bacteria can be killed by photodynamic therapy with low concentrations of dyes. Photodynamic therapy is the combination of light with appropriate wavelength and a photosensitizer. The antimicrobial activity is mainly mediated by singlet oxygen and/or free radicals generated by the photoactivated sensitizer. A flap surgery aiming an immediate implant was made in a residual root with periodontal lesion on upper first premolar. After the extraction, a microbiological sample with sterile paper points was harvested. Then, the photosensitizer was applied in the infected alveolus and irradiated with low-intensity laser, ?= 660 nm, P= 30 mW and E= 9 J . After the photodynamic therapy, a new microbiological sample was harvested. Subsequently, it was prepared the implant bed with conical burs and then the implant was placed. Patient was medicated with antibiotic after surgery. The microbiological analysis showed a significant reduction of Prevotella sp., Fusobacterium sp. and Streptococcus beta-hemoliticus. This finding suggests that photodynamic therapy is an alternative method to disinfect alveolus before implant placement. Therefore, this study highlights the need for future work in the area of photodynamic therapy to reduce bacteria without harming host tissue.
Local Treatment using high and low-power laser on herpes simplex
2004 - MULLER, K.P.; YAMADA JUNIOR, A.M.; SUGAYAMA, S.T.; RIBEIRO, M.S.
Herpes simplex (HSV) is commonly encountered in the dentistry practice disappearing after 10 to 14 days. Recently alternative treatments have been introduced, among those laser therapy. The aim of this study is to evaluate the efficacy of laser therapy in patients with perioral herpes simplex infection. A 32 years old female was treated with high-intensity laser therapy (HILT) in vesicle phase using a Nd:YAG laser, l= 1064 nm, P= 1,5 W, f= 15 Hz on days 1 and 2 to drainage the vesicles. Low-intensity laser therapy (LILT) was applied on the affected area in the 3 consecutive days with a GaAlAs laser, l= 830 nm, D= 5 J/cm2. On the other hand, a 7 years male patient, which presented the vesiculo-ulcerative stage, only LILT (l= 660 nm, D= 4 J/cm2) was carried out. For both cases, it was observed that the course of the infection was quicker than the normal. Seven days after treatment beginning the lesions were healed. These findings suggest that LILT associated or not to HILT is a efficient and promising treatment for HSV. Further larger studies aiming at confirming these data and investigating the LILT mechanisms of action should be performed.
Bacterial reduction by photodynamic therapy in peri-implantitis
2004 - YAMADA JUNIOR, A.M.; HAYEK, R.R.A.; GIOSO, M.A.; FERREIRA, J.; BATISTA SOBRINHO, C.A.; RIBEIRO, M.S.
Progressive peri-implantar bone losses, which are accompanied by inflammatory process in the soft tissues is referred to as peri-implantitis. The aim of this study was to compare the effects of lethal photosensitization with the conventional technique on bacterial reduction in ligature induced peri-implantitis in dogs. Seventeen third premolars of eight Labrador dogs were extracted and, immediately after, the implants were submerged. After osseointegration, peri-implantitis was induced. After 4 months, ligature were removed and the same period was waited for natural induction of bacterial plaque. The dogs were randomly divided into two groups. In the conventional group, they were treated with the conventional techniques of mucoperiosteal flaps for scaling the implant surface and irrigation with chlorexidine. In the laser group, only mucoperiosteal scaling was carried out before photodynamic therapy. On the peri-implantar pocket an azulene paste was introduced and a GaAlAs low-power laser (l= 660 nm, P= 30 mW, E= 5,4 J and Dt= 3 min.) was applied. Microbiological samples were obtained before and immediately after treatment. The results of this study showed that Prevotella sp., Fusobacterium e S. Beta-haemolyticus were significantly reduced for the conventional and laser groups (100%,99.8%; 100%,100%; 85.7%,97.6%, respectively).
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.
Photosensitization of Actinobacillus actinomycetemcomitans with malachite green and methylene blue: microbiological analysis
2006 - YAMADA JUNIOR, A.M.; PRATES, R.A.; HASHIMOTO, M.C.; SUZUKI, L.C.; CAI, S.; RIBEIRO, M.S.
Histological analysis in ligature induced periodontitis in rats following photodynamic therapy
2006 - YAMADA JUNIOR, A.M.; PRATES, R.A.; SUZUKI, L.C.; VILLA, N.; CAI, S.; RIBEIRO, M.S.
Bactericidal effect of malachite green and red laser on Antinobacillus actinomycetemcomitans
2007 - PRATES, RENATO A.; YAMADA JUNIOR, AECIO M.; SUZUKI, LUIS C.; HASHIMOTO, MARIA C.E.; CAI, SILVANA; SOARES, SHEILA G.; GOMES, LAERCIO; RIBEIRO, MARTHA S.
Comparative study between the effects of photodynamic therapy and conventional therapy on microbial reduction in ligature-induced peri-implantitis in dogs
2005 - HAYEK, R.R.A.; ARAUJO, N.S.; GIOSO, M.A.; FERREIRA, J.; BAPTISTA SOBRINHO, C.A.; YAMADA JUNIOR, A.M.; RIBEIRO, M.S.
The irradiation parameters investigation of photodynamic therapy on yeast cells
2008 - PRATES, RENATO A.; SILVA, ERIQUES G. da; YAMADA JUNIOR, AECIO M.; SUZUKI, LUIS C.; PAULA, CLAUDETE R.; RIBEIRO, MARTHA S.
It has been proposed that photodynamic therapy (PDT) can inactivate microbial cells. A range of photosensitizers and light sources were reported as well as different fluence parameters and dye concentrations. However, much more knowledge regarding to the role of fluences, irradiation time and irradiance are required for a better understanding of the photodynamic efficiency. The aims of this study were to investigate the role of light parameters on the photoinactivation of yeast cells, and compare cell survivors in different growing phases following PDT. To perform this study, a suspension (106cfu/mL) of Candida albicans ATCC-90028 was used in log and stationary-phase. Three irradiances 100mW/cm2, 200mW/cm2 and 300mW/cm2 were compared under 3min, 6min and 9min of irradiation, resulting in fluences of 18, 36, 54, 72,108 and 162J/cm2. The light source used was a laser emitting at 660nm with output power of 30, 60 and 90mW. As photosensitizer, 100μΜ methylene blue was used. PDT was efficient against yeast cells (6 log reduction) in log and stationary-phase. Neither photosensitizer nor light alone presented any reduction of cell viability. The increase of irradiance and time of irradiation showed a clearly improvement of cell photoinactivation. Interestingly, the same fluences in different irradiances presented dissimilar effects on cell viability. The irradiance and time of irradiation are important in PDT efficiency. Fluence per se is not the best parameter to compare photoinativation effects on yeast cells. The growing-phases presented the same susceptibility under C. albicans photoinactivation.
Photosensitization of Aggregatibacter actinomycetemcomitans with methylene blue: A microbiological and spectroscopic study
2008 - YAMADA JUNIOR, AECIO; PRATES, RENATO A.; CAI, SILVANA; RIBEIRO, MARTHA S.
The aim of this study was to determinate the efficiency of methylene blue (MB) to kill cultures of Aggregatibacter actinomycetemcomitans under red light and to investigate MB photobleaching by optical absorption spectroscopy. Bacteria were diluted in aqueous solution, putted in glass tubes and distributed in 5 groups: (L-MB-) control group; (L+MB-) laser alone by 5min; (L-MB+) MB alone through 5min; (3L+MB+) MB+laser 3min; (5L+MB+) MB+laser 5min. Laser parameters were P=30mW, λ=660nm, E=9J in 5min and E=5.4J in 3min. The samples were diluted and bacterial colonies were counted and converted into colony forming units (CFU). Absorption spectra of the MB-stained bacterial suspension and photosensitized bacterial suspension were obtained. Groups L-MB-, L+MB-, and L-MB+ did not show a decrease in CFU/mL. L+MB+ groups showed a significant decrease in CFU/mL but no statistically significant differences were observed between 3min and 5min. Spectroscopy showed that MB is photodegraded after irradiation and that dimer species are more notably consumed than monomeric species. These results suggest that MB is a suitable photosensitizer to reduce A. actinomycetemcomitans, and that 3min of irradiation are enough to produce a significant effect. Due to the spectral changes observed on MB solution after irradiation a type I mechanism may be involved.