Maria Stella Moreira

Effect of phototherapy with low intensity laser on local and systemic immunomodulation following focal brain damage in rat.

Brain injury is responsible for significant morbidity and mortality in trauma patients, but controversy still exists over therapeutic management for these patients. The objective of this study was to analyze the effect of phototherapy with low intensity lasers on local and systemic immunomodulation following cryogenic brain injury. Laser phototherapy was applied (or not-controls) immediately after cryogenic brain injury performed in 51 adult male Wistar rats. The animals were irradiated twice (3 h interval), with continuous diode laser (gallium-aluminum-arsenide (GaAlAs), 780 nm, or indium-gallium-aluminum-phosphide (InGaAlP), 660 nm) in two points and contact mode, 40 mW, spot size 0.042 cm(2), 3 J/cm(2) and 5 J/cm(2) (3 s and 5 s, respectively). The experimental groups were: Control (non-irradiated), RL3 (visible red laser/ 3 J/cm(2)), RL5 (visible red laser/5 J/cm(2)), IRL3 (infrared laser/3 J/cm(2)), IRL5 (infrared laser/5 J/cm(2)). The production of interleukin-1IL-1beta (IL-1beta), interleukin6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-alpha) was analyzed by enzyme immunoassay technique (ELISA) test in brain and blood samples. The IL-1beta concentration in brain of the control group was significantly reduced in 24 h (p<0.01). This reduction was also observed in the RL5 and IRL3 groups. The TNF-alpha and IL-6 concentrations increased significantly (p<0.01 and p<0.05, respectively) in the blood of all groups, except by the IRL3 group. The IL-6 levels in RL3 group were significantly smaller than in control group in both experimental times. IL-10 concentration was maintained stable in all groups in brain and blood. Under the conditions of this study, it is possible to conclude that the laser phototherapy can affect TNF-alpha, IL-1beta and IL-6 levels in the brain and in circulation in the first 24 h following cryogenic brain injury.

Effect of laser phototherapy in the prevention and treatment of chemo-induced mucositis in hamsters

The aim of this study was to investigate the effect of laser phototherapy (LPT) in the prevention and/or treatment of oral mucositis induced by 5-fluorouracil (5-FU; Eurofarma, São Paulo, Brazil) in hamsters. Ninety-six hamsters were divided into four groups (n=24): Control (no treatment); Preventive [LPT from day (D) D-5 to D+5]; Therapeutic (LPT from D+5 to D+15); and Combined (preventive plus therapeutic LPT from D-5 to D+15). The animals received an intraperitoneal injection of 5-FU on Days 0 and 2. The pouch mucosa was scratched on Days 3 and 4. The irradiation parameters were: indium-gallium-aluminum-phosphide (InGaAlP) diode laser (MM Optics, São Carlos, Brazil) (660 nm), beam area of 0.036 cm2, 40 mW, 1.11 W/cm2, 6.6 J/cm2, power density applied daily of 39.6 J/cm2, in punctual mode (six points and six seconds per point) and contact mode, one application per day. The animals were sacrificed on Days 0, 5, 10 and 15 (n=6) and weighed, and the pouch mucosa was removed for histopathological analysis. Clinical and corresponding histological scores were compared using ANOVA and Tukeys test (p≤0.05). Similar weight losses ranging from 5% to 10% occurred in all groups. The therapeutic group had significantly lower clinical and histological scores than the other groups at Day 10. This study showed that positive effects on oral mucositis management were obtained only when LPT was applied in the therapeutic protocol (from D+5 to D+15 after chemotherapy).

Single session of Nd:YAG laser intracanal irradiation neutralizes endotoxin in dental root dentin

Abstract. Endotoxins released in the dental root by Gram-negative microorganisms can be neutralized by calcium hydroxide, when this medication is applied inside the root canal for at least seven days. However, several clinical situations demand faster root canal decontamination. Thus, for faster endotoxin neutralization, endodontists are seeking additional treatments. The in vitro study tested whether or not intracanal Nd:YAG laser irradiation would be able to neutralize endotoxin within the human dental root canal in a single session. Twenty-four human teeth with one root were mounted between two chambers. After conventional endodontic treatment, root canals were contaminated with Escherichia coli endotoxin. Then they were irradiated or not (controls) in contact mode with an Nd:YAG laser (1.5 W, 15 Hz, 100 mJ and pulse fluency of 124  J/cm2). The endotoxin activity was measured using the limulus lysate technique and data were statistically compared (p≤0.05). The concentration of active endotoxin measured in the negative control group was significantly lower than that of the positive control group (p=0.04). The concentrations of endotoxin in both irradiated groups were significantly lower than that of the positive control group (p=0.027) and similar to that of negative control group (p=0.20). A single session of intracanal Nd:YAG laser irradiation is able to neutralize endotoxin in the dental root tissues.

Photobiomodulation of mesenchymal stem cells encapsulated in an injectable rhBMP4-loaded hydrogel directs hard tissue bioengineering

Photobiomodulation (PBM) therapy displays relevant properties for tissue healing and regeneration, which may be of interest for the tissue engineering field. Here, we show that PBM is able to improve cell survival and to interact with recombinant human Bone Morphogenetic Protein 4 (rhBMP4) to direct and accelerate odonto/osteogenic differentiation of dental derived mesenchymal stem cells (MSCs). MSCs were encapsulated in an injectable and thermo‐responsive cell carrier (Pluronic® F‐127) loaded with rhBMP4 and then photoactivated. PBM improved MSCs self‐renewal and survival upon encapsulation in the Pluronic® F‐127. In the presence of rhBMP4, cell odonto/osteogenic differentiation was premature and markedly improved in the photoactivated MSCs. An in vivo calvarial critical sized defect model demonstrated significant increase in bone formation after PBM treatment. Finally, a balance in the reactive oxygen species levels may be related to the favorable results of PBM and rhBMP4 association. PBM may act in synergism with rhBMP4 and is a promise candidate to direct and accelerate hard tissue bioengineering.

Effect of low intensity laser therapy in an experimental model of cranio-encephalic trauma in rats

The aim of this study was to analyze the effects of phototherapy with low intensity laser on the inflammatory reaction after rat brain injury. Cryogenic injury was performed at the brain of 16 male Wistar rats (250-300g) using a cooper probe at -80º C. Immediately, 24 h and 48 h later, the rats received laser irradiation using a GaAlAs laser (830 nm, 100 mW). The samples were randomly divided into four groups (n= 4 per group): A: control (non- irradiated); B: energy density of 14.28 J/cm2; C: 28.57 J/cm2; D: 42.85 J/cm2. Three days later, the cerebral vascular permeability and the inflammatory cells at the trauma site were evaluated. For vascular permeability analysis, 2 h prior sacrifice an intra vascular injection of Evans blue stain was done in the rats. For inflammatory cells counting, frozen samples were sectioned and the histological slides were stained with Giemsa. The data were compared by either ANOVA or Kruskall-Wallis complemented by the Dunns test. The irradiated groups presented higher cerebral vascular permeability than controls (A: 2.6 ± 0.8; B:12.0 ± 2.0; C: 13.1 ± 4.1, and D: 12.4 ± 1.8; p=0.016). The inflammatory cell numbers of irradiated samples were similar to controls (A: 65 ± 6; B:85 ± 9; C: 84 ±14, and D: 83 ± 3; p=0.443). The data showed that phototherapy with low intensity laser modulates the inflammatory reaction in the brain by increasing the cerebral vascular permeability after a cryogenic trauma.

New Uses for Rehabilitation Protocol for Oral Sinus Communications in ARONJ Patients

This report presents a new use for rehabilitation protocol for oral sinus communications in patients with antiresorptive agent-induced osteonecrosis of the jaw. The treatment plan consisted of constructing an atraumatic complete denture with rounded edges, made with nontoxic resin, to prevent any injury to the mucosa and recurrence of the disease. The patient was followed up for 4 years, without any complications, and was socially reintegrated by resuming the normal life he experienced before tooth loss.

New rehabilitation protocol for oral sinus communications in BRONJ patients.

Sir, The management of bisphosphonate-related osteonecrosis jaw (BRONJ) is challenging because most surgical and medical interventions may not eradicate it. More alarming is performing prosthetic rehabilitation of these patients, subject not enough discussed in the literature. The demand of BRONJ patients in need of prosthetic rehabilitation has being dramatically increased in Brazil. We believe that this is also a huge problem in others countries too. The professionals are concerned about the possible induction of new lesions due to trauma caused by the fabrication and use of prostheses. However, the oral rehabilitation of BRONJ patients is of paramount importance for their quality of life. For circumvent this problem our research group in the School of Dentistry of the University of São Paulo developed a new protocol for obtaining prosthesis with chemical and mechanical characteristics conferring an atraumatic and atoxic pattern (Table 1). After more than 4 years of follow-up there is no recurrence of the BRONJ lesions. There is a lack of information on the use of osseointegrated implants in these patients, thus, due to the long half-life of BFs in the patients, or because patient will be still using BFs, new BRONJ lesions can occur, particularly in areas subject to trauma, our group opted for a denture fabrication based on those indicated for patients irradiated for head and neck cancer. Several parameters were considered for the construction of such prosthesis, including resin type, polymerization cycle, prosthesis finishing and internal adaptation, as described in the chart below. We believe that oral health professionals and their BRONJ patients worldwide will be beneficiated with this prosthetic rehabilitation protocol. We hope to have more discussion about this subject for now on.

The symbolic value of prostheses in maxillofacial rehabilitation

http://dx.doi.org/10.1016/j.oraloncology.2014.09.003 1368-8375/ 2014 Elsevier Ltd. All rights reserved. q DOI of original article: http://dx.doi.org/10.1016/j.oraloncology.2010.02.02 We read the article entitled ‘‘Quality of Life Perspectives in Patients with Oral Cancer,’’ published in Oral Oncology with great interest and would like to congratulate Rogers [1] on his important contribution to the field. The author reports on head and neck mutilation and its effects on patient quality of life, pointing out that restoring dentition is important for the sake of appearance, psychosocial well-being and self-esteem. The author also states that oral rehabilitation plays a decisive role in maintaining the quality of life of patients, and needs to be taken into consideration along with motivation and individual patient needs. Our group has been working in the maxillofacial prosthetic rehabilitation of cancer patients since 1998, and agrees with Dr. Rogers. Based on our clinical practice and on the research recently conducted by our group, we would like to extend the discussion a bit further by stressing the importance of listening carefully to patients and analyzing their discourses, as an integral aspect of treatment. Patient feedback, in its different forms, confirms that rehabilitation rather than merely restoring aesthetics, chewing and speech can restore the patient’s confidence in his/her cure, and the feeling that their rehabilitation is indeed feasible. Our group is conducting qualitative research to understand the deeper implications of maxillofacial prosthetics rehabilitation on a patient’s quality of life, by evaluating how patients who were submitted to oral resections refer to their rehabilitation process. What they communicated to us surprised us, since they revealed meanings that showed the magnitude of the importance that they gave to prosthetic rehabilitation. One of the patients who most impacted our team said: