Search

Objective: This randomized clinical trial evaluated the sensitive return of the lower alveolar nerve (LAN) using two photobiomodulation therapy (PBMT) techniques, after the extraction of lower third molars or implant surgery. Materials and methods: Sixty participants with sensory impairment of LAN were randomly divided into three groups ( n  = 20): group C-systemic medication (control-ETNA ® , 01 capsule, 8/8 h, 30 days); group laser therapy (LT) (808 nm, 100 mW, 40 sec/point, 4 J/point, intra/extraoral, irradiation following nerve path); group laser acupuncture (LA) (same parameters as the LT group, applied at six acupuncture points on the affected side (ST 4 [Dicang], M-HN-18 [Jiachengjiang], CV 24 [Chengjiang], ST 5 [Daying], ST 6 [Jiache], and point A1 [YNSA]). The following evaluations were performed, at predetermined times: general perception of paresthesia, thermal perception, vibratory mechanical perception, two-point discrimination, pain perception, and tactile perception. Data were analyzed by two-way analysis of variance (ANOVA), followed by the Tukey, except for the two-point discrimination, which was analyzed using the chi-square test. Results: In general and thermal perception, both PBMTs had better results than control; regarding cold perception, only the LT group was statistically superior to control. LA presented inferior results of neural regeneration for tests of perception of pain and tactile at the lip, and of tactile perception at the chin. In the other tests, there was no statistical difference among the groups. Conclusions: LT and the conventional drug treatment had the same effectiveness and both were superior to LA for the treatment of paresthesia of the LAN after oral surgeries.

Photobiomodulation is being widely applied for improving dermal or mucosal wound healing. However, the underlying cellular and molecular processes that directly contribute to its effects remain poorly understood. Pericytes are relevant cells involved in the wound microenvironment and could be one of the main targets of photobiomodulation due to their plasticity and perivascular localization. Herein, we investigate tissue repair under the photobiomodulation stimulus using a pericyte labeled (or reporter) transgenic mice. Using a model of two contralateral back wounds, one the control and the other photoactivated daily (660 nm, 20 mW, 0.71 W/cm 2 , 5 J/cm 2 , 7 s, 0.14 J), we showed an overall influx of immune and undifferentiated cells and higher mobilization of a potent pericyte subpopulation (Type-2 pericytes) in the photoactivated wounds in comparison to the controls. Doppler analysis showed a significant increase in the blood flow in the photoactivated wounds, while marked vascular supply was observed histologically. Histochemical analysis has indicated more advanced stages of tissue repair after photoactivation. These data suggest that photobiomodulation significantly accelerates tissue repair through its vascular effects with direct recruitment of pericytes to the injury site.

The effect of low-level laser therapy (LLLT) on the healing of skin lesions has been evaluated in many studies; however, the molecular mechanisms involved in the biostimulatory effects resulting from this treatment need to be better understood. The paper aims to analyze the effects of LLLT (660 nm) at doses of 1 and 5 J/cm 2 on cell viability and expression of vascular endothelial growth factor (VEGF) and interleukin (IL6) genes in L929 fibroblast cells. The dose-response curve was performed with the GaInAlAs (660 nm) laser-treated cells at energy rates of 1 and 5 J/cm 2 . Cell viability was quantified at 24, 48, and 72 h after irradiation and the effects of TLBP on the cytoskeleton and endoplasmic reticulum were evaluated by fluorescence microscopy and the RT-qPCR method was used for the analysis of gene expression. It was observed that the 72 h group had a statistically significant increase in cell viability compared to the 48 h group (p < 0.01) and when compared to the 72 h control (p = 0.03). In 72 h, a greater distribution of the cytoskeleton filaments and the more evident endoplasmatic reticulum was verified, indicating an increase in the protein synthesis when compared with the control group. In the expression of the VEGF gene, a significant increase of 1.98 times (p < 0.05) in the number of transcripts was observed; whereas for the IL6 gene, a decrease of the transcripts was 4.05 times (p < 0.05), both occurring within 72 h after irradiation at 5 J/cm 2 . The LLLT (660 nm) at the dose of 5 J/cm 2 should modulate cellular viability, upregulated VEGF, and downregulated IL6 expression of messenger RNA in culture of L929 fibroblast cells.

Objective: The aim of the present study was to conduct a review of the literature about adhesion on erbium laser prepared cavities, related to the specific conditions of the irradiated dentin substrate and the effects on bond strength values., Background Data: Advances in adhesive restorative techniques significantly influenced modern restorative dentistry. The concept of "minimally invasive dentistry" aims to perform more conservative treatment of cavities in which the removal of sound dentin is no longer necessary. This approach, which relies on the concept of adhesion of restorative materials to the mineralized dental tissues, is considered to be a contemporary outcome in dentistry. Similarly, laser technology in restorative dentistry opened new possibilities and strategies as alternatives to conventional treatment. Considering the clinical aspects of the use of erbium lasers for caries removal, cavity preparations, and substrate conditioning, treatment with lasers can be considered to be an efficient technique with wide acceptance by patients., Methods: Computerized and manual searches were conducted for studies through 2015 that addressed the topic., Results: According to the literature, there is no defined standard protocol concerning the information that articles must provide, making a definitive protocol very difficult to establish. Data varied from the type of adhesive and resin composite used, substrate, and parameters (power, energy density, pulse duration, irradiation time, distance, cooling system) to the bond strength test methodology used., Conclusions: Further studies are necessary in order to define a standard protocol with positive results and higher bond strength values when using erbium lasers. Detailed information concerning laser parameters should be implemented. Also, longitudinal clinical studies should be developed in the search for new parameters that behave favorably in the irradiated substrate.

Objective: The aim of this retrospective study was to evaluate the effectiveness of laser therapy for acceleration and recovery of nerve sensitivity after orthognathic or minor oral surgeries, by analysis of clinical records of patients treated at the Special Laboratory of Lasers in Dentistry (LELO, School of Dentistry, University of São Paulo), throughout the period 2007-2013., Background Data: Nerve tissue lesions may occur during various dental and routine surgical procedures, resulting in paresthesia. Laser therapy has been shown to be able to accelerate and enhance the regeneration of the affected nerve tissue; however, there are few studies in the literature that evaluate the effects of treatment with low-power laser on neural changes after orthognathic or minor oral surgeries., Methods: A total of 125 clinical records were included, and the data on gender, age, origin of the lesion, nerve, interval between surgery and onset of laser therapy, frequency of laser irradiation (one or two times per week), final evolution, and if there was a need to change the irradiation protocol, were all recorded. These data were related to the recovery of sensitivity in the affected nerve area. Descriptive analyses and modeling for analysis of categorical data (α=5%) were performed., Results: The results from both analyses showed that the recovery of sensitivity was correlated with patient age (p=0.015) and interval between surgery and onset of laser therapy (p=0.002)., Conclusions: Within the limits of this retrospective study, it was found that low- power laser therapy with beam emission band in the infrared spectrum (808 nm) can positively affect the recovery of sensitivity after orthognathic or minor oral surgeries.

Post-traumatic nerve repair represents a major challenge to health sciences. Although there have been great advances in the last few years, it is still necessary to find methods that can effectively enhance nerve regeneration. Laser therapy has been widely investigated as a potential method for nerve repair. Therefore, in this article, a review of the existing literature was undertaken with regard to the effects of low-power laser irradiation on the regeneration of traumatically/surgically injured nerves. The articles were selected using either electronic search engines or manual tracing of the references cited in key papers. In electronic searches, we used the key words as "paresthesia", "laser therapy", "low-power laser and nerve repair", and "laser therapy and nerve repair", considering case reports and clinical studies. According to the findings of the literature, laser therapy accelerates and improves the regeneration of the affected nerve tissues, but there are many conflicting results about laser therapy. This can be attributed to several variables such as wavelength, radiation dose, and type of radiation. All the early in vivo studies assessed in this research were effective in restoring sensitivity. Although these results indicate a potential benefit of the use of lasers on nerve repair, further double-blind controlled clinical trials should be conducted in order to standardize protocols for clinical application.

Objective: The aim of the present study was to compare the effect of low-level laser therapy (LLLT) and low-intensity pulsed ultrasound (LIPUS) on the cytoskeleton and endoplasmic reticulum of L929 cells. Thermal and non-thermal physical mechanisms such as LLLT and LIPUS induce clinically significant responses in cells, tissues, and organs., Materials and Methods: L929 fibroblast cell cultures were irradiated with LLLT and subjected to LIPUS. Cultures irradiated with the laser (904 nm) were divided into three groups: group I, control (no irradiation); group II, irradiated at 6 J/cm(2); and group III, irradiated at 50 mJ/cm(2). Cultures subjected to ultrasound were divided into five groups: group I, control (no LIPUS); group II, LIPUS at 0.2 W/cm(2) in pulsed mode at 10% (1:9 duty cycle); group III, LIPUS at 0.6 W/cm(2) in pulsed mode at 10% (1:9 duty cycle); group IV, LIPUS at 0.2 W/cm(2) in pulsed mode at 20% (2:8 duty cycle); and group V, LIPUS at 0.6 W/cm(2) in pulsed mode at 20% (2:8 duty cycle). Each group was irradiated at 24-h intervals, with the following post-treatment incubation times: 24, 48, and 72 h. The effects of LLLT and LIPUS on the cytoskeleton and endoplasmic reticulum was evaluated by the use of fluorescent probes and with fluorescence microscopy analysis., Results: The results following LLLT and LIPUS demonstrate that ultrasound was more effective than laser on fibroblast cell cultures when the endoplasmic reticulum was assessed, whereas there was a better distribution of the filaments of the cytoskeleton in the cells subjected to laser irradiation., Conclusion: The study demonstrated that both LLLT and LIPUS promote changes on the cellular level. However, LIPUS was more effective than LLLT at the doses used here, as assessed by fluorescence microscopy, which revealed increased reticulum activity and increased protein synthesis. However, when the organization of actin filaments was assessed, LLLT achieved a better result.

Objective: The purpose of the present study was to evaluate the effect of biomodulation on osteoblastic cells using a gallium-aluminium-arsenide diode laser., Background Data: Low-level laser therapy (LLLT) is a non-pharmacological therapeutic resource to which biological tissues respond well, producing such effects as the acceleration of bone formation and bone repair., Materials and Methods: Osteoblastic cell cultures (OFCOL II) were irradiated with a gallium-aluminium-arsenide diode laser (GaAlAs lambda = 830 nm; 50 mW; 3 J/cm(2); 600-microm-diameter optical fiber) and divided into two groups: group 1--irradiated cells, and group 2--non-irradiated cells. Irradiation occurred at 24-h intervals for a total of 3 d. After each interval, the cells were marked with Mito Tracker Orange dye to assess the biostimulatory effect on mitochondrial activity and cell proliferation using an MTT assay., Results: Intense grouping of mitochondria in the perinuclear region was observed at 24 h and 48 h following irradiation. Changes from a filamentous to a granular appearance in mitochondrial morphology and mitochondria distributed throughout the cytoplasm were observed 72 h following proliferation. Such changes led to an in vitro proliferation process, as confirmed by the MTT assay., Conclusion: LLLT has shown itself capable of altering mitochondrial activity and the population of OFCOL II cells.

Objective: The objective of this study was to compare the effect of low-level laser therapy (LLLT) and low-intensity pulsed ultrasound (LIPUS) on fibroblast cell culture. Several methods, including ultrasound treatment and LLLT, are being used to facilitate tissue repair and healing processes., Materials and Methods: L929 fibroblast cell cultures were irradiated with low-level laser energy and LIPUS. Cultures irradiated with ultrasound were divided into five groups: group 1: control (did not receive irradiation); group 2: 0.2 W/cm(2) in pulsed mode at 10% (1:9 duty cycle); group 3: 0.6 W/cm(2) in pulsed mode at 10% (1:9 duty cycle); group 4: 0.2 W/cm(2) in pulsed mode at 20% (2:8 duty cycle); and group 5: 0.6 W/cm(2) in pulsed mode at 20% (2:8 duty cycle). Cultures irradiated with laser energy were divided into three groups: group 1: control (did not receive irradiation); group 2: 6 J/cm(2); and group 3: 50 mJ/cm(2). Each group was irradiated at 24-h intervals, with the following incubation periods post-irradiation: 24, 48, and 72 h; after each irradiation cycle the cultures were analyzed using MTT [3-(4.5-dimethylthiazol-2-yl)-2.5 diphenyltetrazolium bromide]., Results: Analysis of results after LLLT and LIPUS demonstrated that the effect of laser therapy on fibroblast cell culture was greater than that of LIPUS (p < 0.05)., Conclusion: Results demonstrated that LLLT significantly increased fibroblastic activity more than LIPUS. Therefore, in the first and second phases of tissue repair, laser treatment may be more effective than ultrasound treatment.