Publications by authors named "Antônio Luiz Barbosa Pinheiro"

57 Publications

Photobiomodulation Therapy in the Proliferation and Differentiation of Human Umbilical Cord Mesenchymal Stem Cells: An Study.

J Lasers Med Sci 2020 3;11(4):469-474. Epub 2020 Oct 3.

Laser Center, School of Dentistry, Universidade de Pernambuco, Camaragibe, PE, Brazil.

Since photobiomodulation therapy (PBMT) favors mesenchymal stem cell (MSC) preconditioning before MSC transplantation, increasing the proliferation of these cells without molecular injuries by conserving their characteristics, in the present study we analyzed the effect of PBMT on the proliferation and osteogenic differentiation of human umbilical cord mesenchymal stem cells (hUCMSCs). Irradiation with an InGaAIP Laser (660 nm, 10 mW, 2.5 J/cm , 0.08 cm spot size, and 10 s) was carried out. The cells were divided into four groups: CONTROL [cells grown in Dulbecco's Modified Eagle Medium (DMEM)], OSTEO (cells grown in an osteogenic medium); PBMT (cells grown in DMEM+PBMT), and OSTEO+PBMT (cells grown in an osteogenic medium plus PBMT). The cell proliferation curve was obtained over periods of 24, 48 and 72 hours using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Osteogenic differentiation was analyzed by the formation of calcium nodules over periods of 7, 14 and 21 days. Morphometric analysis was performed to quantify the total area of nodular calcification. The highest cell proliferation and cell differentiation occurred in the OSTEO+PBMT group, followed by the PBMT, OSTEO and CONTROL groups respectively, at the observed times ( <0.05). PBMT enhanced the osteogenic proliferation and the differentiation of hUCMSCs during the periods tested, without causing damage to the cells and preserving their specific characteristics, a fact that may represent an innovative pretreatment in the application of stem cells.
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http://dx.doi.org/10.34172/jlms.2020.73DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7736934PMC
October 2020

Photobiomodulation and Pain Reduction in Patients Requiring Orthodontic Band Application: Randomized Clinical Trial.

Biomed Res Int 2020 25;2020:7460938. Epub 2020 May 25.

Unit of Orthodontics and Paediatric Dentistry, Section of Dentistry-Department of Clinical, Surgical, Diagnostic and Paediatric Sciences, University of Pavia, Pavia, Italy.

Purpose: The aim of this study was to investigate the effect of Photobiomodulation (PBM) in managing orthodontic pain intensity over time in patients requiring band application on upper first molars.

Methods: Maxillary first molars were banded. In the trial group, each molar received single-session PBM on two buccal and two palatal points ( = 830 ± 10 nm; 150 mW, 7.5 J/cm; spot of 0.1 cm; 5 sec per point), while the control group received a placebo treatment. All patients were asked to answer five pain rating scales to assess pain intensity at 5 minutes and 1, 12, 24, and 72 hours and completed a survey describing the type of pain and its temporal course in the next 7 days.

Results: 26 patients (mean age 11.8 years) were randomly assigned to a control or a trial group. The trial group showed significantly lower pain intensities ( < 0.05) at 5 min ( = 0.92, SD = 1.32), 1 h ( = 0.77, SD = 1.01), and 12 h ( = 0.77, SD = 1.54) after band application compared to the control group (5 min: = 1.62, SD = 1.26; 1 h: = 1.77, SD = 1.92; and 12 h: = 1.77, SD = 2.17), whereas no difference between groups ( > 0.05) was found at 24 h (trial: = 0.62, SD = 1.71; control: = 1.08, SD = 1.75) and 72 h (trial: = 0.31, SD = 0.75; control: = 0.15, SD = 0.55). Patients in the control group reported more frequently the presence of "compressive pain" (58.8%, < 0.05) from the appliance during the week after the application, while the trial group showed higher frequency of "no pain" (46.2%, < 0.05). However, PBM did not affect the pain onset (trial: = 10.86, SD = 26.97; control: = 5.25, SD = 7.86), peak (trial: = 15.86, SD = 26.29; control: 6.17, SD = 7.96), and end time (trial: 39.57, SD = 31.33; control: = 22.02, SD = 25.42) reported by the two groups ( > 0.05).

Conclusions: PBM might be considered a promising alternative to decrease general pain intensity, although not affecting the typical pain cycle, in terms of the onset, peak, and ending times.
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http://dx.doi.org/10.1155/2020/7460938DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7273483PMC
March 2021

Anti-Trypanosoma cruzi effect of the photodynamic antiparasitic chemotherapy using phenothiazine derivatives as photosensitizers.

Lasers Med Sci 2020 Feb 12;35(1):79-85. Epub 2019 May 12.

Center of Biophotonics, School of Dentistry, Federal University of Bahia (UFBA), 62 Araujo Pinho Ave, Canela, Salvador, BA, 40110-150, Brazil.

Chagas disease is endemic in Latin America and increasingly found in non-endemic countries. Its treatment is limited due to the variable efficacy and several side effects of benznidazole. Photodynamic antimicrobial chemotherapy (PACT) may be an attractive approach for treating Chagas disease. Here, the trypanocidal activity of PACT was investigated in vitro using phenothiazine derivatives. The cytotoxicity of both, methylene blue (MB) and toluidine blue (TBO), was determined on macrophages cultures using AlamarBlue method. The trypanocidal activity of the two photosensitizers was initially evaluated by determining their IC values against trypomastigote forms. After this, the trypanocidal effect was evaluated in cultures of infected macrophages using an automatized image analysis protocol. All experiments were performed in the dark and in the clear phase (after a photodynamic exposure). The compounds showed no cytotoxicity in both phases at the tested concentrations. The IC values for the sole use of MB and TBO were 2.6 and 1.2 μM, respectively. The photoactivation of the compounds using a fixed energy density (J/cm) caused a reduction of the IC values to 1.0 and 0.9 μM, respectively. It was found that, on infected macrophage, the use of TBO significantly reduced the number of infected cells and parasitic load, and this effect was increased in the presence of light. The results of the present study are indicative that PACT may be considered as both selective and effective therapeutic intervention for treating Chagas disease.
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http://dx.doi.org/10.1007/s10103-019-02795-4DOI Listing
February 2020

Photobiomodulation Therapy in Bone Repair Associated with Bone Morphogenetic Proteins and Guided Bone Regeneration: A Histomorphometric Study.

Photomed Laser Surg 2018 Nov;36(11):581-588

6 Center of Biophotonics, School of Dentistry, Federal University of Bahia , Salvador, Brazil .

Objective: To evaluate the efficacy of photobiomodulation for bone repair of critical surgical wounds with implants of bone morphogenetic proteins (BMPs) and bovine biological membranes, using histological and histomorphometric analysis.

Background: Tissue engineering has been developing rapidly through the use of various biomaterials for the treatment of bone defects, such as mechanical barriers consisting of biological membranes and implants of biomaterials for bone supply.

Materials And Methods: Thirty-two male rats were divided into four groups (n = 8): group I-C: control; group II-PT: photobiomodulation therapy; group III-PM: Gen-Pro BMPs+Gen-Derm membrane; and group IV-PMPT: Gen-Pro BMPs+Gen-Derm membrane+photobiomodulation therapy. A 3 mm bone cavity was performed in the upper third of the lateral surface of the right rat femur to obtain a bone defect considered to be critical. The irradiated groups received seven applications of AlGaAs diode laser 830 nm, P = 40 mW, continuous wave (CW) emission mode, f ∼ 0.6 mm, 4 J/cm per point (north, south, east, and west) at 48 h intervals, for a total of 16 J/cm per session (final dose: 112 J/cm). Bone repair was evaluated at sacrifice 15 and 30 days after the procedure. The specimens were embedded in paraffin and stained with hematoxylin and eosin and Picrosirius for analysis by light microscopy and by the Leica interactive measurement module software. Statistical analysis was performed (p < 0.05%).

Results: Histological analysis confirmed the histomorphometric results, with the experimental groups showing bone neoformation of significantly higher quality and quantity at the end of 30 days compared with the control group.

Conclusions: Photobiomodulation therapy was effective for bone repair mainly when associated with BMPs and a biological membrane. The results of this study are promising and stimulate further scientific and clinical research.
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http://dx.doi.org/10.1089/pho.2017.4421DOI Listing
November 2018

Does laser phototherapy influence the proliferation of myoepithelial cells in the salivary gland of hypothyroid rats?

J Photochem Photobiol B 2017 Aug 12;173:681-685. Epub 2017 Jul 12.

Department of Propedeutics and Integrated Clinic, School of Dentistry, Federal University of Bahia, Salvador, Brazil. Electronic address:

Thyroid hormones influence both development and growth of organs and tissues and guarantee metabolic demands that interfere with the quality of digestive secretions, including those of the salivary glands. Laser phototherapy - LPT can modulate various biological phenomena and its diverse effects permit the action on different cell types. The aim of this study was to evaluate the influence of laser phototherapy on myoepithelial cells of salivary glands of hypothyroid rats. Forty-two albino Wistar rats were divided into two main groups: euthyroid (EU) and hypothyroid (HYPO). Hypothyroidism was induced using propylthiouracil (PTU) for 4weeks. Each group was divided into subgroups: control (without laser) and laser groups (Red/infrared - IR). LPT was used on the submandibular gland and was carried out using a diode laser (λ660 or λ780nm, 40mW, spot size 0.04cm, irradiation area 1cm, 300s, 6J/cm per gland, 12J/cm per session) and started two weeks after PTU treatment. LPT was repeated every other day for two weeks. After animal death, the glands were removed, dissected and processed for immunohistochemical analysis. It was observed an increase in the number of myoepithelial cells of hypothyroid control rats in comparison to euthyroid controls (p=0.001). Visible LPT (λ660nm) caused significant higher proliferation of myoepithelial cells in EU rats when compared to IR LPT (λ 780nm)(p≤0.001).It is concluded that, despite the LPT protocol used did not influence myoepithelial proliferation on hypothyroid rats it significantly increased the proliferation on euthyroid animals.
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http://dx.doi.org/10.1016/j.jphotobiol.2017.07.008DOI Listing
August 2017

Biochemical changes on the repair of surgical bone defects grafted with biphasic synthetic micro-granular HA + β-tricalcium phosphate induced by laser and LED phototherapies and assessed by Raman spectroscopy.

Lasers Med Sci 2017 Apr 10;32(3):663-672. Epub 2017 Feb 10.

Center for Innovation, Technology and Education-CITE, Universidade Anhembi Morumbi-UAM, Parque Tecnológico de São José dos Campos, Estr. Dr. Altino Bondensan, 500, Eugênio de Melo, São José dos Campos, SP, 12247-016, Brazil.

This work aimed the assessment of biochemical changes induced by laser or LED irradiation during mineralization of a bone defect in an animal model using a spectral model based on Raman spectroscopy. Six groups were studied: clot, laser (λ = 780 nm; 70 mW), LED (λ = 850 ± 10 nm; 150 mW), biomaterial (biphasic synthetic micro-granular hydroxyapatite (HA) + β-tricalcium phosphate), biomaterial + laser, and biomaterial + LED. When indicated, defects were further irradiated at a 48-h interval during 2 weeks (20 J/cm per session). At the 15th and 30th days, femurs were dissected and spectra of the defects were collected. Raman spectra were submitted to a model to estimate the relative amount of collagen, phosphate HA, and carbonate HA by using the spectra of pure collagen and biomaterials composed of phosphate and carbonate HA, respectively. The use of the biomaterial associated to phototherapy did not change the collagen formation at both 15 and 30 days. The amount of carbonate HA was not different in all groups at the 15th day. However, at the 30th day, there was a significant difference (ANOVA, p = 0.01), with lower carbonate HA for the group biomaterial + LED compared to biomaterial (p < 0.05). The phosphate HA was higher in the groups that received biomaterial grafts at the 15th day compared to clot (significant for the biomaterial; p < 0.01). At the 30th day, the phosphate HA was higher for the group biomaterial + laser, while this was lower for all the other groups. These results indicated that the use of laser phototherapy improved the repair of bone defects grafted with the biomaterial by increasing the deposition of phosphate HA.
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http://dx.doi.org/10.1007/s10103-017-2165-2DOI Listing
April 2017

Laser and LED phototherapy on midpalatal suture after rapid maxilla expansion: Raman and histological analysis.

Lasers Med Sci 2017 Feb 24;32(2):263-274. Epub 2016 Nov 24.

Center of Biophotonics, School of Dentistry, Federal University of Bahia, Av. Araújo Pinho, 62, Canela, Salvador, BA, CEP 40110-150, Brazil.

The aim of this study was to analyze the effect of laser or LED phototherapy on the acceleration of bone formation at the midpalatal suture after rapid maxilla expansion. Forty-five rats were divided into groups at 7 days (control, expansion, expansion and laser irradiation, and expansion and LED irradiation) and into 14 days (expansion, expansion and laser in the 1st week, expansion and LED in the 1st week, expansion and laser in the 1st and 2nd weeks, expansion and LED in the 1st and 2nd weeks). Laser/LED irradiation occurred every 48 h. Expansion was accomplished with a spatula and maintained with a triple helicoid of 0.020-in stainless steel orthodontic wire. A diode laser (λ780 nm, 70 mW, spot of 0.04 cm, t = 257 s, SAEF of 18 J/cm) or a LED (λ850 ± 10 nm, 150 ± 10 mW, spot of 0.5 cm, t = 120 s, SAEF of 18 J/cm) was applied in one point in the midpalatal suture immediately behind the upper incisors. Raman spectroscopy and histological analyses of the suture region were carried and data was submitted to statistical analyses (p ≤ 0.05). Raman spectrum analysis demonstrated that irradiation increases hydroxyapatite in the midpalatal suture after expansion. In the histological analysis of various inflammation, there was a higher production of collagen and osteoblastic activity and less osteoclastic activity. The results showed that LED irradiation associated to rapid maxillary expansion improves bone repair and could be an alternative to the use of laser in accelerating bone formation in the midpalatal suture.
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http://dx.doi.org/10.1007/s10103-016-2108-3DOI Listing
February 2017

Estimating the concentration of urea and creatinine in the human serum of normal and dialysis patients through Raman spectroscopy.

Lasers Med Sci 2016 Sep 8;31(7):1415-23. Epub 2016 Jul 8.

Biomedical Engineering Institute, Universidade Camilo Castelo Branco - UNICASTELO, Parque Tecnológico de São José dos Campos, Estr. Dr. Altino Bondesan, 500, Eugênio de Melo, São José dos Campos, 12247-016, SP, Brazil.

Urea and creatinine are commonly used as biomarkers of renal function. Abnormal concentrations of these biomarkers are indicative of pathological processes such as renal failure. This study aimed to develop a model based on Raman spectroscopy to estimate the concentration values of urea and creatinine in human serum. Blood sera from 55 clinically normal subjects and 47 patients with chronic kidney disease undergoing dialysis were collected, and concentrations of urea and creatinine were determined by spectrophotometric methods. A Raman spectrum was obtained with a high-resolution dispersive Raman spectrometer (830 nm). A spectral model was developed based on partial least squares (PLS), where the concentrations of urea and creatinine were correlated with the Raman features. Principal components analysis (PCA) was used to discriminate dialysis patients from normal subjects. The PLS model showed r = 0.97 and r = 0.93 for urea and creatinine, respectively. The root mean square errors of cross-validation (RMSECV) for the model were 17.6 and 1.94 mg/dL, respectively. PCA showed high discrimination between dialysis and normality (95 % accuracy). The Raman technique was able to determine the concentrations with low error and to discriminate dialysis from normal subjects, consistent with a rapid and low-cost test.
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http://dx.doi.org/10.1007/s10103-016-2003-yDOI Listing
September 2016

Evaluation of laser phototherapy (λ 780 nm) after dental replantation in rats.

Dent Traumatol 2016 Dec 30;32(6):488-494. Epub 2016 May 30.

Laboratory of Oral Surgical Pathology, Department of Oral Pathology, School of Dentistry, Federal University of Bahia, Salvador, Bahia, Brazil.

Background/aim: Tooth replantation is the treatment of choice in cases of avulsion although the outcomes are variable. The teeth can be lost due to external root resorption. The aim of this study was to histologically assess of the effect of laser phototherapy (λ780 nm) on replanted teeth in rats.

Material And Methods: Sixty Wistar Albinus rats had their maxillary right incisors extracted and were then divided into four groups: G1-absence of storage medium; G2-milk as storage medium; G3-milk as storage medium followed by a laser irradiation of the root surfaces and entrance of the alveolus (λ = 780 nm; P = 70 mW; CW; DE = 21 J/cm ); G4-milk as storage medium, laser irradiation as in G3 before replantation. After this procedure, laser irradiation was performed on the buccal and palatal mucosa (8.4 J/cm per session) every 48 h for 15 days. The animals were euthanized 15, 30, and 60 days after replantation.

Results: The histological results showed that after 15 days, G4 exhibited intense chronic inflammation with the presence of clastic cells and moderate external inflammatory root resorption (P < 0.05) when compared with G3, in which these outcomes were not observed. At the 30th day, G1, G2, and G4 showed chronic inflammation varying from discrete to moderate, as well as intense external inflammatory root resorption. G3 remained without any inflammation and external inflammatory root resorption up to the 60th day.

Conclusions: The use of laser phototherapy on the root surface and at the entrance of the alveolus prior to replantation had a positive biomodulative effect on alveolar repair after tooth replantation in rats.
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http://dx.doi.org/10.1111/edt.12289DOI Listing
December 2016

Quantifying creatinine and urea in human urine through Raman spectroscopy aiming at diagnosis of kidney disease.

J Biomed Opt 2016 Mar;21(3):37001

Universidade Camilo Castelo Branco-UNICASTELO, Biomedical Engineering Institute, Parque Tecnológico de São José dos Campos, Estrada Dr. Altino Bondesan, 500, São José dos Campos, São Paulo 12247-016, Brazil.

Due to their importance in the regulation of metabolites, the kidneys need continuous monitoring to check for correct functioning, mainly by urea and creatinine urinalysis. This study aimed to develop a model to estimate the concentrations of urea and creatinine in urine by means of Raman spectroscopy (RS) that could be used to diagnose kidney disease. Midstream urine samples were obtained from 54 volunteers with no kidney complaints. Samples were subjected to a standard colorimetric assay of urea and creatinine and submitted to spectroscopic analysis by means of a dispersive Raman spectrometer (830 nm, 350 mW, 30 s). The Raman spectra of urine showed peaks related mainly to urea and creatinine. Partial least squares models were developed using selected Raman bands related to urea and creatinine and the biochemical concentrations in urine measured by the colorimetric method, resulting in r = 0.90 and 0.91 for urea and creatinine, respectively, with root mean square error of cross-validation (RMSEcv) of 312 and 25.2 mg/dL, respectively. RS may become a technique for rapid urinalysis, with concentration errors suitable for population screening aimed at the prevention of renal diseases.
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http://dx.doi.org/10.1117/1.JBO.21.3.037001DOI Listing
March 2016

Photodynamic Antimicrobial Chemotherapy (PACT) in osteomyelitis induced by Staphylococcus aureus: Microbiological and histological study.

J Photochem Photobiol B 2015 Aug 9;149:235-42. Epub 2015 Jun 9.

Center of Biophotonics, School of Dentistry, Federal University of Bahia, Salvador, BA 40110-150, Brazil; National Institute of Optics and Photonics, University of São Paulo, Physics Institute of São Carlos, São Carlos, SP 13560-970, Brazil; Camilo Castelo Branco University, Núcleo do Parque Tecnológico de São José dos Campos, São José dos Campos, SP 12247-004, Brazil. Electronic address:

Osteomyelitis is an inflammation either of medullar spaces or of the surface of cortical bones, which represents a bacterial infection. Photodynamic Antimicrobial Chemotherapy (PACT) is a treatment based on a cytotoxic photochemical reaction that induces a series of metabolic reactions and culminates in bacterial suppression. Such effect led to the idea that it could be used as a treatment of osteomyelitis. Following approval by the Animal Experimentation Committee of the School of Dentistry of the Federal University of Bahia, the present randomized study used eighty Wistar rats with the aim to evaluate, by microbiological and histological analysis, the effects of Photodynamic Antimicrobial Chemotherapy - PACT on tibial surgical bone defects in rats infected by Staphylococcus aureus. The animals were divided in groups: Control (non-infected); Control Osteomyelitis Induction; Saline solution; Photosensitizer; Red Laser and PACT - on this group, a diode laser (40mW; λ660nm ∅=0.04cm(2), CW, 10J/cm(2)) was used in combination with 5μg/ml of toluidine blue as the photosensitizer. On the microbiological study, immediately after treatment, the PACT group presented a bacterial reduction of 97.4% (p<0.001). Thirty days after treatment, there was a bacterial reduction of more than 99.9% (p<0.001). In the histological study, it was observed that the PACT group demonstrated an intense presence of osteocytes and absence of bone sequestration and micro-abscesses. The PACT using toluidine blue was effective in reducing the number of S. aureus enabling a better quality bone repair.
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http://dx.doi.org/10.1016/j.jphotobiol.2015.06.005DOI Listing
August 2015

Assessing the biochemical changes of tendons of rats in an experimental model of tenotomy under therapeutic ultrasound and LEDs (625 and 945 nm) by near-infrared Raman spectroscopy.

Lasers Med Sci 2015 Aug 23;30(6):1729-38. Epub 2015 Jun 23.

Faculdade Santo Agostinho - FSA, Av. Valter Alencar, 665, Teresina, PI, 64019-625, Brazil.

Given the complexity of the tendon repair process, where the neoformed scar tissue tends to prevent or hamper the tendon from performing its normal functions, ultrasound (US) and light-emitting diode (LED) devices have been applied to modulate the tendon repair process. This study aimed to compare the anti-inflammatory and healing effects of therapeutic US and LED in an experimental model of tenotomy using histomorphometry and Raman spectroscopy. Forty Wistar rats (235 ± 8.3 g) were separated into four groups: tenotomy (TC; control), tenotomy associated with ultrasound (US; 1 MHz, 0.5 W/cm(2)), tenotomy associated with LED at 625 nm (LR; 4 J/cm(2)), and tenotomy associated with LED at 945 nm (LIR; 4 J/cm(2)), in two experimental periods of 7 and 14 days. Histomorphometry showed a decrease of inflammatory cells (macrophages and polymorphonuclear leukocytes) for the group treated with US compared to the TC group (ANOVA, p < 0.0001) and the LIR group compared to the TC group (p < 0.05) at the seventh day, indicating an anti-inflammatory effect. In relation to the LR and TC groups, there was no significant difference. Raman spectroscopy revealed that the LR group presented an increased synthesis of collagen I compared to the other treatments and the TC groups on the 14th day (p < 0.01). US therapy showed an adjuvant effect with anti-inflammatory action, and the LED therapy at 625 nm showed an increase in collagen synthesis, contributing to the process of tendon healing.
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http://dx.doi.org/10.1007/s10103-015-1779-5DOI Listing
August 2015

Influence of laser photobiomodulation (GaAlAs) on salivary flow rate and histomorphometry of the submandibular glands of hypothyroid rats.

Lasers Med Sci 2015 May 27;30(4):1275-80. Epub 2015 Feb 27.

Faculty of Dentistry, Federal University of Bahia, Salvador, Brazil,

The aim of this study was to analyze the influence of laser photobiomodulation in salivary flow, weight, and histomorphometry of the submandibular glands of hypothyroid rats. Fifty-six male Wistar albino rats were divided in euthyroid group and hypothyroid group, treated with propylthiouracil (PTU) to induce hypothyroidism. Each group was divided into control (without laser) and laser groups (GaAlAs): λ660 nm (40 mW), λ780 nm (40 mW), and λ780 nm (70 mW). The laser application on the submandibular gland occurred after 2 weeks of PTU treatment and repeatedly during 2 weeks every 48 h. The rats were anesthetized, tracheostomized, and the evaluation of the salivary flow rate (μL/min/100 g body weight) was made by the weight of the saliva collected for 15 min from the first drop. After the animals' death, the glands were dissected and processed for histological analysis. There was an evident reduction of the salivary flow of hypothyroid rats in all groups in comparison to euthyroid group (Mann-Whitney test, p < 0.05). No significant difference was found in the salivary flow of rats that received laser photobiomodulation compared with their control groups. Histological analysis revealed a decrease in the parenchyma of the salivary glands of hypothyroid rats, but the laser was not able to reverse this process. Hypothyroid rats irradiated or not with laser showed acini and acinar cells with significantly smaller areas than euthyroid groups. The laser photobiomodulation protocol used was not able to change salivary flow or reverse the acinar atrophy process in the submandibular glands of hypothyroid rats.
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http://dx.doi.org/10.1007/s10103-015-1725-6DOI Listing
May 2015

Effect of laser (λ 660 nm) and LED (λ 630 nm) photobiomodulation on formocresol-induced oral ulcers: a clinical and histological study on rodents.

Lasers Med Sci 2015 Jan 30;30(1):389-96. Epub 2014 Oct 30.

Center of Biophotonic and Division of Endodontic, School of Dentistry, Federal University of Bahia, Salvador, Bahia, Brazil.

The aim of this study was to evaluate, clinically and histologically, the influence of laser and LED photobiomodulation in the healing of formocresol-induced oral mucosa ulcers of rats. We used 60 Wistar rats in which oral ulcers were induced on the gingiva of the lower incisors. Forty-eight hours after inducing the ulcers, the animals were divided into three groups: laser, LED, and untreated. Animals from the laser group received irradiation with GaAlAs, 660 nm, CW, 40 mW, φ 4 mm(2), 4.8 J/cm(2). Animals from the LED group received irradiation with InGaAIP, 630 nm, 150 mW, 4.8 J/cm(2), 0.8 cm spot. Forty-eight hours after oral ulcer induction, both irradiations were applied in a punctuate manner in the center of the ulcer at 48-h interval until the end of the experimental period. The animals were killed at 3, 5, 7, and 11 days after day 0. The results of the clinical evaluation showed that the laser and LED phototherapies were able to accelerate the healing of formocresol-induced oral ulcers, which occurred first in the laser group (ANOVA, p < 0.05). Histologically, there was a slight variation between LED and laser therapy; therefore, the laser group proved to be effective in accelerating wound healing, especially at 5 days, whereas the LED group was more effective at the end of the experimental period. It was concluded that laser and LED photobiomodulation were effective in accelerating the healing of formocresol-induced oral ulcers in both clinical and histological aspects.
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http://dx.doi.org/10.1007/s10103-014-1680-7DOI Listing
January 2015

Infrared LED light therapy influences the expression of fibronectin and tenascin in skin wounds of malnourished rats--a preliminary study.

Acta Histochem 2014 Sep 12;116(7):1185-91. Epub 2014 Jul 12.

Laboratory of Surgical Pathology, School of Dentistry, Federal University of Bahia, Salvador, Bahia, Brazil. Electronic address:

The aim of this investigation was to evaluate the effect of infrared (λ 846±20nm) LED irradiation on the expression profile of the extracellular matrix protein components, tenascin and fibronectin on skin wounds induced in well nourished and malnourished rats. Eighteen albino rats (21 days old) were randomly divided into a well-nourished group (standard diet) and a malnourished group (regional basic diet). After receiving the diet for 70 days, skin wounds were created and the animals were subdivided into three groups: well-nourished control (n=6), malnourished control (n=6), and malnourished+LED irradiated (λ 846±20nm, 100mW, 4J/cm(2)) (n=6). The animals were sacrificed 3 and 7 days after injury and histological sections were immunostained for both proteins. They were examined for the presence, intensity, distribution and pattern of immunolabeling. At 3 days, the distribution of tenascin was shown to be greater in the wound bed of malnourished animals compared to the well-nourished group. The intensity and distribution of tenascin was shown to be lower in the malnourished LED irradiated group compared to the malnourished control. There was a significant difference regarding the presence of fibronectin in the malnourished and well-nourished groups after 7 days (p=0.03). The intensity of fibronectin was slight (100%) in the irradiated group and moderate to intense in the malnourished control group. The results of the present study indicate that infrared LED irradiation modulates positively the expression of tenascin and particularly fibronectin.
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http://dx.doi.org/10.1016/j.acthis.2014.06.006DOI Listing
September 2014

Cellular effect of low-level laser therapy on the rate and quality of bone formation in mandibular distraction osteogenesis.

Photomed Laser Surg 2014 Jun;32(6):315-21

1 Oral and Maxillofacial Surgery Department, Dental Faculty, AJA University of Medical Sciences , Tehran, Iran .

Objective: Therapeutic lasers have been shown to influence bone physiology and repair. The aim of the present investigation was to evaluate the use of a GaAlAs (λ:810 nm) laser in distraction osteogenesis.

Background Data: To reduce problems associated with distraction osteogenesis and shorten the time required for treatment, it is desirable to accelerate the process of bone formation.

Materials And Methods: Eighteen male rabbits underwent corticotomy of mandibular body, and customized distraction devices were inserted. After a 5-day latency period, the mandibles were lengthened by 0.5 mm/day for 10 days. The rabbits were divided into two groups. A GaAlAs (λ: 810 nm) laser beam with the parameters power (P), 200 mW; energy density (ED), 3 J/cm(2); time (T), 7.5 sec; power density (PD) 400 mW/cm(2); energy (E) 1.5 J and spot diameter, 0.8 mm was directed medially and laterally in the study group; the control group received no laser treatment. The exposure continued with six more doses every other day. Three rabbits from each of the two groups were euthanized on the 10th, 20th, and 40th days post-distraction (consolidation) period.

Results: Both light microscopy and scanning electron microscopic (SEM) analysis showed significant improvement in new bone formation in the study group at the 10th and 20th days compared with the control group, but the difference was more prominent on the 10th day. By the 40th day, there were no significant differences between the two groups.

Conclusions: This study shows that a low-level GaAlAs (λ:810 nm; P, 200 mW) laser hastens new bone formation only in the early stages of the consolidation period in distraction osteogenesis, and has no significant effect in later stages.
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http://dx.doi.org/10.1089/pho.2013.3559DOI Listing
June 2014

Do laser/LED phototherapies influence the outcome of the repair of surgical bone defects grafted with biphasic synthetic microgranular HA + β-tricalcium phosphate? A Raman spectroscopy study.

Lasers Med Sci 2014 Sep 14;29(5):1575-84. Epub 2014 Mar 14.

Center of Biophotonics, School of Dentistry, Federal University of Bahia, Av. Araújo Pinho, 62, Canela, Salvador, BA, 40110-150, Brazil.

The treatment of bone loss is difficult. Many techniques are proposed to improve repair, including biomaterials and, recently, phototherapies. This work studied bone mineralization by Raman spectroscopy assessing intensities of Raman peaks of both inorganic (∼ 960, ∼ 1,070 cm(-1)) and organic (∼ 1,454 cm(-1)) contents in animal model. Six groups were studied: clot, laser, light-emitting diode (LED), biomaterial (HA + β-tricalcium phosphate), laser + biomaterial, and LED + biomaterial. Defects at right tibia were performed with a drill. When indicated, defects were further irradiated at a 48-h interval during 2 weeks. At the 15th and 30th days, the tibias were withdrawn and analyzed. The ∼ 960-cm(-1) peak was significantly affected by phototherapy on both clot- and biomaterial-filled defects. The ∼ 1,070-cm(-1) peak was affected by both time and the use of the LED light on clot-filled defects. On biomaterial-filled defects, only the use of the laser light significantly influenced the outcome. No significant influence of either the time or the use of the light was detected on clot-filled defects as regards the ∼ 1,454-cm(-1) peak. Raman intensities of both mineral and matrix components indicated that the use of laser and LED phototherapies improved the repair of bone defects grafted or not with biphasic synthetic microgranular HA + β-tricalcium phosphate.
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http://dx.doi.org/10.1007/s10103-014-1563-yDOI Listing
September 2014

Do laser and led phototherapies influence mast cells and myofibroblasts to produce collagen?

Lasers Med Sci 2014 Jul 20;29(4):1405-10. Epub 2014 Feb 20.

Center of Biophotonics, School of Dentistry, Federal University of Bahia, Av. Araújo Pinho, 62, Canela, Salvador, Bahia, CEP 40110-150, Brazil,

Laser and LED phototherapies accelerate tissue repair. Mast cells induce the proliferation of fibroblasts and the development of local fibrosis. Increased numbers of myofibroblasts and mast cells are frequently found together in a normal wound repair, suggesting that mediators produced by the mast cells could play a role in the regulation of myofibroblast differentiation and function. The aim of this study was to analyze the involvement of mast cells on the synthesis of collagen and their influence on myofibroblast differentiation in the late phase of tissue repair on wounds treated with LLLT (λ 660 nm, 10 J/cm(2), 40 mW, 252 s) or LED (λ 630 ± 10 nm, 10 J/cm(2), 115 mW, 87 s). A 1 × 1-cm surgical wound was created on the dorsum of 30 rats divided into three groups of ten animals each: control, laser, and LED. The animals of each group were irradiated and sacrificed 7 and 14 days after injury. The statistical analysis was performed using the Mann-Whitney and Spearman correlation tests. Laser light improved the collagen deposition rate along the time points (p = 0.22), but when compared to the control groups during the periods studied, the number of mast cells decreased significantly (p ≤ 0.05). With respect to myofibroblasts, the results showed a trend to their reduction. No statistical significances were observed for LED light according to the parameters used in this study. It is concluded that the mast cell and myofibroblast population might participate in the collagen formation of irradiated wounds particularly in relation to laser phototherapy.
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http://dx.doi.org/10.1007/s10103-014-1537-0DOI Listing
July 2014

Effect of low-level laser therapy (λ660 nm) on angiogenesis in wound healing: a immunohistochemical study in a rodent model.

Braz Dent J 2013 ;24(4):308-12

The aim of the present investigation was to evaluate the angiogenesis on dorsal cutaneous wounds in a rodent model treated with λ660 nm laser light. New vessel formation is a multistep process involving vessel sprouting, endothelial cell migration, proliferation and tube formation. Although several in vivo studies have shown that laser phototherapy influences tissue repair, a fully understanding of angiogenesis mechanisms are not yet known. Twenty-four young adult male Wistar rats weighing between 200 and 250 g were used. Under general anesthesia, one excisional wound was created on the dorsum of each animal and they were randomly distributed into two groups: one control and one treated with laser (λ660 nm, 16 mW, 10 J/cm2). Each group was subdivided into three subgroups according to the animal death timing (2, 4 and 6 days). Laser irradiation started immediately after surgery and was repeated every other day during the experiment and marked with Sirius Red, specific for collagen, and immunomarked with anti-TGF-β and anti-von Willebrand factor. Marked sections underwent histological analysis by light microscopy and the mean area of the wound of each animal was calculated and analyzed by ANOVA and Tukey's test (α=0.05). Although at some death periods, collagen expression and number of blood vessels on irradiated animals were higher than in the control ones, no significant differences were found at any time in relation to TGF-β expression (p>0.05). It was concluded that laser treatment (λ660 nm) contributed to increase angiogenesis.
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http://dx.doi.org/10.1590/0103-6440201301867DOI Listing
September 2015

Raman spectroscopy detection of molecular changes associated with two experimental models of osteoarthritis in rats.

Lasers Med Sci 2014 Mar 25;29(2):797-804. Epub 2013 Aug 25.

Grupo de Estudos e Pesquisa em Ciências da Saúde (GEP-CS), Instituto Federal de Educação, Ciência e Tecnologia do Sul de Minas Gerais, Campus Muzambinho. Estrada de Muzambinho, km 35, Caixa Postal 02, 37890-000, Muzambinho, Minas Gerais, Brazil,

The aim of the present study was to evaluate the feasibility of applying Raman spectroscopy in probing the molecular changes in terms of collagen deposition and tissue remodeling associated with two well-established experimental models of osteoarthritis (OA) in knee of rats. In order to evaluate alterations in the articular surface area, the menisci-covered tibial region was assessed into three groups as follows: control (joint preserved) and two models of experimental knee OA: collagenase-induced model (n = 8) and treadmill exercise-induced model (n = 8). Each group was examined for molecular changes using spectral parameters related to cartilage, subchondral bone, and bone tissues. A significant increase of Raman ratios related to mineralization and tissue remodeling was found (p < 0.05), suggesting that both models were successful for inducing OA in rats. The significantly lower phenylalanine content and higher crystallinity in the treadmill exercise-induced model of OA than collagenase-induced model of OA (p < 0.05) indicated that the OA pathogenesis was model-dependent. Thus, this work suggests that the Raman spectroscopy technique has potential for the diagnosis and detection of cartilage damage and monitoring of subchondral bone and bone in OA pathogenesis at the molecular level.
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http://dx.doi.org/10.1007/s10103-013-1423-1DOI Listing
March 2014

A new preclinical approach for treating chronic osteomyelitis induced by Staphylococcus aureus: in vitro and in vivo study on photodynamic antimicrobial therapy (PAmT).

Lasers Med Sci 2014 Mar 25;29(2):789-95. Epub 2013 Aug 25.

Center of Biophotonics, School of Dentistry, Federal University of Bahia, 62 Araujo Pinho Ave, Canela, Salvador, Bahia, 40110-150, Brazil,

Osteomyelitis is an acute or chronic inflammation in the marrow spaces in the superficial or cortical bone, and can be associated with bacterial or fungal infections. Chronic osteomyelitis represents a major health problem due to its difficult treatment and increased morbidity. Photodynamic antimicrobial therapy (PAmT) is a treatment based on a cytotoxic photochemical reaction in which a bright light produced by a laser system and an active photosensitizer absorbed by cells leads to a process of activation that induces a series of metabolic reactions that culminates a bacterial killing. The aim of the present randomized study was to evaluate, by in vitro and in vivo microbiological analysis, the effects of PAmT on tibial surgical bone defects in rats infected by Staphylococcus aureus using bacterial counts carried out immediately and after 30 days after treatment as outcome measure. In the preliminary in vitro study, a diode laser (λ660 nm; 40 mW; ϕ = 0.4 cm(2); 5 or 10 J/cm(2)) and 5, 10, and 15 μg/mL toluidine blue were tested, and the best parameter was chosen for the in vivo study. The concentration of 5 μg/mL was selected to perform the decontamination of S. aureus-infected tibial bone defects in rats. The findings were subjected to statistical analysis. For all PAmTs groups, with the different concentrations, treatment showed significant reductions (p < 0.001) in the amount of bacteria. The in vivo study PAmT group presented a bacterial reduction of 97.4% (p < 0.001). The PAmT using toluidine blue was effective in reducing the number of S. aureus in both in vitro and in vivo studies.
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http://dx.doi.org/10.1007/s10103-013-1422-2DOI Listing
March 2014

Use of laser fluorescence in dental caries diagnosis: a fluorescence x biomolecular vibrational spectroscopic comparative study.

Braz Dent J 2013 ;24(1):59-63

Biophotonics Center, Dental School, Federal Universityof Bahia, Salvador, BA, Brazil.

The aim of this work was to verify the existence of correlation between Raman spectroscopy readings of phosphate apatite (~960 cm-1), fluoridated apatite (~575 cm-1) and organic matrix (~1450 cm-1) levels and Diagnodent® readings at different stages of dental caries in extracted human teeth. The mean peak value of fluorescence in the carious area was recorded and teeth were divided in enamel caries, dentin caries and sound dental structure. After fluorescence readings, Raman spectroscopy was carried out on the same sites. The results showed significant difference (ANOVA, p<0.05) between the fluorescence readings for enamel (16.4 ± 2.3) and dentin (57.6 ± 23.7) on carious teeth. Raman peaks of enamel and dentin revealed that ~575 and ~960 cm-1 peaks were more intense in enamel caries. There was significant negative correlation (p<0.05) between the ~575 and ~960 cm-1 peaks and dentin caries. It may be concluded that the higher the fluorescence detected by Diagnodent the lower the peaks of phosphate apatite and fluoridated apatite. As the early diagnosis of caries is directly related to the identification of changes in the inorganic tooth components, Raman spectroscopy was more sensitive to variations of these components than Diagnodent.
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http://dx.doi.org/10.1590/0103-6440201302123DOI Listing
April 2014

Effects of imiquimod and low-intensity laser (λ660 nm) in chemically induced oral carcinomas in hamster buccal pouch mucosa.

Lasers Med Sci 2013 May 1;28(3):1017-24. Epub 2012 Sep 1.

Center of Biophotonics, School of Dentistry, Federal University of Bahia, Av. Araújo Pinho, 62, Canela, Salvador, BA, 40110-150, Brazil,

Squamous cell carcinoma (SCC) is the most common neoplasm of the oral cavity. It is aggressive, highly proliferative, and metastatic. This study aimed to evaluate the effect of LLLT and imiquimod on DMBA chemically induced lesions on the oral mucosa of hamsters. SCCs were induced on 25 hamsters. Animals of G1 (control 1) were killed and the presence of tumors confirmed; G2 (control 2) suffered no interventions for additional 4 weeks; animals of G3 (laser treatment) were irradiated (λ660 nm, 50 mW, CW, Ø=3 mm, 0.07 cm(2), 714.2 mW/cm(2), 133 s, 95 J/cm(2), 6.65 J) at every other day for 4 weeks; animals of G4 (imiquimod treatment) received 5 % imiquimod three times a week for 4 weeks; and animals of G5 (imiquimod and laser treatment) received both treatments for the same period. Samples were taken and underwent histological analysis by light microscopy and were investigated using immunohistochemistry for S-100(+) dendritic cells. In G1, G2, and G3, the evaluations showed malignant tumors and the absence of S-100(+) dendritic cells in the tumor stroma. In G4, 60 % of the animals had no malignant tumors, and S-100(+) dendritic cells were present in the stroma of the tumors as well as dysplasia. In G5, 40 % of the animals presented SCC, with scarce or no S-100(+) dendritic cells. The imiquimod treatment played a direct effect on SCC, demonstrated by the increased number of S-100(+) dendritic cells, which could suggest an important role of immune surveillance against neoplastic proliferation. Furthermore, its association with laser needs to be further investigated.
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http://dx.doi.org/10.1007/s10103-012-1192-2DOI Listing
May 2013

Laser and LED phototherapies on angiogenesis.

Lasers Med Sci 2013 May 25;28(3):981-7. Epub 2012 Aug 25.

Center of Biophotonics, School of Dentistry, Federal University of Bahia, 62 Araújo Pinho Ave, Canela, Salvador, BA, CEP 40140-110, Brazil.

Angiogenesis is a key process for wound healing. There are few reports of LED phototherapy on angiogenesis, mainly in vivo. The aim of the present investigation was to evaluate histologically the angiogenesis on dorsal cutaneous wounds treated with laser (660 and 790 nm) or LEDs (700, 530, and 460 nm) in a rodent model. Twenty-four young adult male Wistar rats weighting between 200 and 250 g were used on the present study. Under general anesthesia, one excisional wound was created on the dorsum of each animal that were then randomly distributed into six groups with four animals each: G0-control; G1-laser λ660 nm (60 mW, ϕ ∼2 mm, 10 J/cm(2)); G2-laser λ790 nm (50 mW, ϕ ∼2 mm, 10 J/cm(2)); G3-LED λ700 ± 20 nm (15 mW, ϕ ∼16 mm, 10 J/cm(2)); G4-LED λ530 ± 20 nm (8 mW, ϕ ∼16 mm, 10 J/cm(2)); G5-LED λ460 ± 20 nm (22 mW, ϕ ∼16 mm, 10 J/cm(2)). Irradiation started immediately after surgery and was repeated every other day for 7 days. Animal death occurred at the eighth day after surgery. The specimens were removed, routinely processed to wax, cut and stained with HE. Angiogenesis was scored by blood vessel counting in the wounded area. Quantitative results showed that green LED (λ530 ± 20 nm), red LED (λ700 ± 20 nm), λ790 nm laser and λ660 nm laser caused significant increased angiogenesis when compared to the control group. It is concluded that both laser and LED light are capable of stimulating angiogenesis in vivo on cutaneous wounds and that coherence was not decisive on the outcome of the treatment.
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http://dx.doi.org/10.1007/s10103-012-1187-zDOI Listing
May 2013

The efficacy of the use of IR laser phototherapy associated to biphasic ceramic graft and guided bone regeneration on surgical fractures treated with wire osteosynthesis: a comparative laser fluorescence and Raman spectral study on rabbits.

Lasers Med Sci 2013 May 26;28(3):815-22. Epub 2012 Jul 26.

Center of Biophotonics, School of Dentistry, Federal University of Bahia, Av. Araújo Pinho, 62, Canela, Salvador, BA, 40110-150, Brazil.

The aim of the present study was to assess, by Raman spectroscopy and laser fluorescence, the repair of surgical fractures fixed with wire osteosynthesis treated or not with infrared laser (λ780 nm, 50 mW, 4 × 4 J/cm(2) =16 J/cm(2), ϕ=0.5 cm(2), CW) associated or not to the use of hydroxyapatite and guided bone regeneration. Surgical tibial fractures were created under general anesthesia on 15 rabbits that were divided into five groups, maintained on individual cages, at day/night cycle, fed with solid laboratory pelted diet, and had water ad libitum. The fractures in groups II, III, IV, and V were fixed with wires. Animals in groups III and V were grafted with hydroxyapatite (HA) and guided bone regeneration (GBR) technique used. Animals in groups IV and V were irradiated at every other day during 2 weeks (4 × 4 J/cm(2), 16 J/cm(2) =112 J/cm(2)). Observation time was that of 30 days. After animal death, specimens were taken and kept in liquid nitrogen and used for Raman spectroscopy. The Raman results showed basal readings of 1,234.38 ± 220. Groups WO+B+L showed higher readings (1,680.22 ± 822) and group WO+B the lowest (501.425 ± 328). Fluorescence data showed basal readings of 5.83333 ± 0.7. Groups WO showed higher readings (6.91667 ± 0.9) and group WO+B+L the lowest (1.66667 ± 0.5). There were significant differences between groups on both cases (p<0.05). Pearson correlation was negative and significant (R (2)   = -0.60; p<0.001), and it was indicative that, when the Raman peaks of calcium hydroxyapatite (CHA) are increased, the level of fluorescence is reduced. It is concluded that the use of near-infrared lasertherapy associated to HA graft and GBR was effective in improving bone healing on fractured bones as a result of the increasing deposition of CHA measured by Raman spectroscopy and decrease of the organic components as shown by the fluorescence readings.
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http://dx.doi.org/10.1007/s10103-012-1166-4DOI Listing
May 2013

Removal of oral lichen planus by CO2 laser.

Braz Dent J 2011 ;22(6):522-6

Center of Biophotonics, Dental School, Federal University of Bahia, Salvador, BA, Brazil.

The aim of this case report is to present a histologically diagnosed oral lichen planus excised by the CO2 laser. Oral lichen planus is a chronic inflammatory mucocutaneous disease of unknown etiology. Different treatments have been used to manage this condition. A 46 year-old female was referred to the Laser Clinic of the Dental School of the Federal University of Bahia to excise a lesion characterized by white patches on the oral mucosa, which was causing pain and burning sensation and had not respond to treatment with triamcinolone and corticosteroids for 3 months. CO2 laser was used to remove the lesion and the conclusive histopathological diagnosis was oral lichen planus. The patient was followed up over 1 year with no signs of lesion recurrence. The use of the CO2 laser was found to be useful and effective to treat lichen planus.
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http://dx.doi.org/10.1590/s0103-64402011000600014DOI Listing
May 2012

Distribution of mast cells in benign odontogenic tumors.

Tumour Biol 2012 Apr 30;33(2):455-61. Epub 2011 Nov 30.

Department of Oral Pathology, Laboratory of Surgical Pathology, School of Dentistry, Federal University of Bahia, Salvador, Bahia, Brazil.

The aim of this study was to investigate the presence of mast cells in a series of odontogenic tumors. Forty-five cases of odontogenic tumors were investigated using immunohistochemistry for mast cell triptase, and differences between groups were statistically evaluated. Mast cells were present in 96% of odontogenic tumors. Mast cells present in solid ameloblastoma were observed in the tumor stroma surrounding more solid and follicular epithelial islands, with or without squamous metaplasia. The odontogenic mixoma showed few mast cells. In odontogenic tumors with a cystic structure, the mast cells were distributed throughout all areas of the lesions, mainly in keratocystic odontogenic tumor. In addition, the total density of mast cells between all odontogenic tumors showed no significant difference (p > 0.05). A greater mast cells distribution was found in keratocystic odontogenic tumor in relation to adenomatoid odontogenic tumor (p < 0.01), and when the unicystic ameloblastoma and keratocistic odontogenic tumor were compared to the odontogenic myxoma (p < 0.05). Syndrome keratocystic odontogenic tumor showed a higher mean of mast cells when compared with the other tumors of the sample. Mast cells values presented by syndrome keratocystic odontogenic tumor were significantly greater than those of the sporadic keratocystic odontogenic tumor that were not associated with the syndrome (p = 0.03). Mast cells are probably one of the major components of the stromal scaffold in odontogenic tumors. We found significant differences of mast cells between syndrome nonsyndrome keratocystic odontogenic tumors, although their distribution did not seem to have any influence on the biologic behavior of benign odontogenic tumors.
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http://dx.doi.org/10.1007/s13277-011-0274-2DOI Listing
April 2012

Evaluation of the effects of polarized light (λ400-200 nm) on the healing of third-degree burns in induced diabetic and nondiabetic rats.

Photomed Laser Surg 2011 Sep 1;29(9):619-25. Epub 2011 Jun 1.

Center of Biophotonics, School of Dentistry, Federal University of Bahia, Salvador, Bahia, Brazil.

Objective: The study evaluated, by light microscopy, the repair process on third-degree burns on diabetic and nondiabetic rats, illuminated or not, with a polarized light (PL) source.

Background Data: Burns are severe injuries that result in the loss of fluid and destruction of tissue, infection, and shock that may result in death. Diabetes mellitus is a public health problem that, being uncontrolled, causes severe disturbance to the body metabolism, including on wound healing. PL sources have been shown to be effective in improving healing in many situations.

Materials And Methods: Ninety male Wistar rats were divided into two groups (n=45): nondiabetic and diabetic. In one of the groups, diabetes mellitus was induced by streptozotocin. A third-degree burn, measuring 1.5×1.5 cm(2), was created in the dorsum of each animal. Phototherapy (λ400-2000 nm, 10.2 or 20.4 J/cm(2)) started immediately after burning and was repeated daily until animal death (7, 14, and 21 days). Specimens were taken, processed, and stained with H&E and Sirius red and immunomarked with cytokeratin (CK) AE1/AE3. Descriptive analysis was performed by light microscopy.

Results: Animals subjected to phototherapy showed an acceleration of the repair, the dose of 10.2 J/cm(2) being the one that caused best results, including higher deposition of collagen, quicker inflammatory reaction, and improved revascularization.

Conclusions: Our results suggest that the use of PL (10.2 J/cm(2)) improves the healing of third-degree burns on both diabetic and nondiabetic animals.
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http://dx.doi.org/10.1089/pho.2010.2914DOI Listing
September 2011

Effect of LED phototherapy (λ700 ± 20 nm) on TGF-β expression during wound healing: an immunohistochemical study in a rodent model.

Photomed Laser Surg 2011 Sep 19;29(9):605-11. Epub 2011 May 19.

Center of Biophotonics, School of Dentistry, Federal University of Bahia, Salvador, Bahia, Brazil.

Objective: The aim of the present investigation was to evaluate transforming growth factor β (TGF-β) expression on cutaneous wounds in rodents treated or not treated with LED light.

Background: TGF-β is a multifunctional cytokine that presents a central action during tissue repair. Although several studies both in vitro and in vivo have shown that LED phototherapy influences tissue repair, a full understanding of the mechanisms involved in its usage, such as in the modulation of some growth factors, remains unclear.

Materials And Methods: Under general anesthesia, 24 young adult male Wistar rats weighing 200-250 g had one excisional wound created on the dorsum of each, and were randomly distributed into two groups: G0 (Control) and G1 (LED, λ700 ± 20 nm, 16 mW, SAEF = 5 J/cm(2), Illuminated Area = 2 cm(2), 8 mWcm(2), 626 s) Each group was subdivided into three subgroups according to the animal death timing (2, 4, and 6 days). LED phototherapy started immediately after surgery and was repeated every other day during the experimental time. Following animal death, specimens were removed, routinely processed to wax, cut and immunomarked with polyclonal anti-TGF-β, and underwent histological analysis by light microscopy. The mean area of expression of each group was calculated. The data were statistically analyzed using ANOVA and Tukey's test.

Results: The area of the expression of TGF-β on LED-irradiated animals was significantly smaller than on controls at day 2 (p = 0.013). No significant difference was found at later times. It is concluded that the use of LED light, at these specific parameters, caused an inhibition of the expression of TGF-β at an early stage of the healing process.
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http://dx.doi.org/10.1089/pho.2010.2833DOI Listing
September 2011

Laser phototherapy as a treatment for radiotherapy-induced oral mucositis.

Braz Dent J 2011 ;22(2):162-5

Center of Biophotonics, Dental School, Federal University of Bahia, Salvador, BA, Brazil.

Oral mucositis is a harmful side effect of radiotherapy (RT) on the head and neck region. There are encouraging reports on the beneficial aspects of the use of laser light on the treatment of oral mucositis. This paper reports the efficacy of laser phototherapy (LPT) on the treatment of oral mucositis in a patient undergoing RT after surgical removal of a squamous cell carcinoma with osseous invasion of the maxilla. Palatal and commissural lesions were treated with λ660 nm, 40 mW, ∅=4 mm(2), in contact mode, 5 x 2.4 J/cm(2) per point, 14.4 J/cm(2) per session. For treating the lesion on the patient's nasal mucosa, LPT (∅=4 mm(2), λ780 nm, 70 mW, 3 x 2.1 J/cm(2) per point, 6.3 J/cm(2) per session, contact mode) was used on the external area of the nose. A single dose (2.4 J/cm(2)) with the λ660 nm laser, as described before, was applied on the entrance of each nostril. LPT was used 3 times/week during 4 weeks. Treatment results indicate that the use of LPT on oral mucositis was effective and allowed the patient to carry on the RT without interruption. However, long-term and controlled clinical trials are necessary to establish both preventive and curative protocols using LPT.
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http://dx.doi.org/10.1590/s0103-64402011000200013DOI Listing
September 2011
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