Use of photobiomodulation (880 nm) for anesthesia puncture pain reduction: A split-mouth case report.

The objective of this split-mouth case report is to evaluate the effect of photobiomodulation (PBM, 880 nm) on pain control during pterygomandibular puncture. A patient received anesthesia on both sides of the mouth in a randomized manner. On the right side, an 880-nm infrared laser was applied immediately before local anesthesia. On the left side, a sham laser was applied using the same technique. There was a 50% reduction in pain levels on the PBM-treated side compared to the PBM-sham side, as measured by the visual analog scale. Sensitivity tests revealed that anesthesia was more effective on the PBM side. There was no difference in blood pressure. This case report suggests that PBM (880 nm) before anesthesia may alleviate puncture pain associated with pterygomandibular anesthesia. Although these findings are based on a single case report, they can serve as the initial stepping stone for further randomized clinical trials.

Cost analysis of photobiomodulation in tibia fracture in the Brazilian public health system.

Managing tibial fractures requires substantial health resources, which costs the health system. This study aimed to describe the costs of photobiomodulation (PBM) with LEDs in the healing process of soft tissue lesions associated with tibial fracture compared to a placebo. Economic analysis was performed based on a randomized controlled clinical trial, with a simulation of the cost-effectiveness and incremental cost model. Adults (n = 27) hospitalized with tibia fracture awaiting definitive surgery were randomized into two distinct groups: the PBM Group (n = 13) and the Control Group with simulated phototherapy (n = 14). To simulate the cost-effectiveness and incremental cost model, the outcome was the evolution of wound resolution by the BATES-JENSEN scale and time of wound resolution in days. The total cost of treatment for the Control group was R$21,164.56, and a difference of R$7,527.10 more was observed when compared to the treatment of the PBM group. The proposed intervention did not present incremental cost since the difference in the costs to reduce measures between the groups was smaller for the PBM group. When analyzing the ICER (Incremental cost-effectiveness ratio), it would be possible to save R$3,500.98 with PBM and decrease by 2.15 points in the daily average on the BATES-JENSEN scale. It is concluded, therefore, that PBM can be a supportive therapy of clinical and economic interest in a hospital setting.

Effects of the invasive and non-invasive systemic photobiomodulation using low-level laser in experimental models: A systematic review.

Systemic photobiomodulation (PBM) of the blood or over blood vessels has been associated with bio-stimulating, vasodilating, and anti-inflammatory properties. This treatment modality has been used for modulating inflammatory processes, tissue repair, atherosclerosis, and systemic arterial hypertension, and is described more often in clinical studies than experimental models. Therefore, the aim of the present study was to conduct a literature review regarding the effect of systemic PBM involving the intravascular laser irradiation of blood (ILIB) or non-invasive vascular photobiomodulation (VPBM) using low-level laser (LLL) in experimental (animal) models. The PubMed/MEDLINE®, Scopus, SPIE Digital Library, and Web of Science databases were searched for articles on the use of VPBM with LLL in animal models. Nine original articles met the inclusion criteria and were critically evaluated. The variables of interest were the dosimetric laser parameters, different methods for delivering energy, and the main results. The use laser in the red spectrum was more prevalent and VPBM (non-invasive) predominated over ILIB (invasive). No standardization was found in the dosimetric parameters. However, the studies showed the positive effects of VPBM on arterial pressure and blood circulation, the positive effects of ILIB on blood composition and hematological markers, as well as positive effects of both forms of systemic PBM (ILIB and VPBM) on the tissue repair process. In conclusion, the studies evaluated in the present review showed that the use of systemic PBM with ILIB or non-invasive VPBM induced positive effects, modulating metabolic conditions and tissue repair. However, there is a need for standardization in the dosimetric parameters for the different conditions and processes evaluated using experimental models.

Photobiomodulation increases uprighting tooth movement and modulates IL-1ß expression during orthodontically bone remodeling.

This study investigated the effects of photobiomodulation (PBM) in acceleration of orthodontic movement of inferior molar uprighting movement. Thirty-four individuals, with indication of molar uprighting movement for oral rehabilitation, were randomly divided in two groups: verticalization + PBM (808 nm, 100 mW, 1 J per point, 10 points and 25 J/cm2 ) or verticalization + PBM simulation. Elastomeric chain ligatures were changed every 30 days for 3 months. FBM was performed immediately, 24 h, 72 h, 1 and 2 months after activation. The primary outcome was the amount of uprighting movement. Secondary outcomes were pain, amount of medication, OHIP-14 questionnaire, and cytokine IL-1ß. PBM group increase uprighting movement when compared to control after 3 months and modulate IL-1ß expression. For pain control, the amount of medication and OHIP-14 no difference were found. This study suggests that PBM accelerates tooth movement during molar uprighting, due to modulation of IL-1ß during bone remodeling.

Investigation on the effect of antimicrobial photodynamic therapy as an adjunct for management of deep caries lesions-study protocol for a randomized, parallel groups, controlled clinical trial.

BACKGROUND: Alternatively to conventional treatments, chemo-mechanical caries removal agents can be used. A modality of treatment that has been increasing in dentistry is antimicrobial photodynamic therapy (aPDT). Bixa orellana is being researched for application in aPDT. This protocol aims to determine the effectiveness of aPDT with Bixa orellana extract in deep caries lesions. METHODS: A total of 160 teeth with deep occlusal dental caries will be selected and divided into 4 groups: G1 - control group (Caries removal with a low-speed drill); G2 - Partial Caries Removal with Papacarie™ (Fórmula e Ação, São Paulo, SP, Brazil); G3 - Partial Caries Removal with Papacarie™ and application Bixa orellana extract (20%) (Fórmula e Ação, São Paulo, SP, Brazil); G4 - Partial Caries Removal with Papacarie™ and application Bixa orellana extract (20%) with LED (Valo Cordless Ultradent®, South Jordan, UT, USA) (aPDT). After treatment, all the teeth will be restored with glass ionomer cement and followed up clinically and radiographically, with evaluations at immediately, 1 week, and 1, 3, 6, and 12 months. Dentin samples before and after treatment will be analyzed microbiologically. The efficacy of treatments will be assessed with microbiological (colony-forming units, before and after carious tissue removal), radiographic (integrity of the periapical area and eventual changes in the radiolucent zones), and clinical examinations (retention of the restorative material in the cavity and occurrence of secondary caries), as well as with the time required for the procedures and the need for anesthesia during the procedures. In case data distribution is normal, analysis of variance (ANOVA) will be used for both the dependent and independent variables. In case the data distribution is not normal, the Friedman test will be used for the dependent variables. For independent variables, the Kruskal-Wallis test will be used. DISCUSSION: Procedures using aPDT have been developed for the treatment of dental caries, but there are few controlled clinical trials in the literature confirming its efficacy. TRIAL REGISTRATION: This protocol is registered at ClinicalTrials.gov under the number NCT05236205 and it was first posted on 01/21/2022 and last updated on 05/10/2022.

Photodynamic therapy with acai (Euterpe oleracea) and blue light in oral cells: A spectroscopic and cytotoxicity analysis.

OBJECTIVE: To evaluate the potential of photodynamic therapy (PDT) with blue light-emitting diode (LED) 460 nm at 25, 50 and 100 J/cm2 using three concentrations of acai extracts (100, 40, and 10 mg/ml), in the proliferation and viability of head and neck tumor lines (SCC9). METHODS: Three groups of cells were analyzed for 3 days in an in vitro assay with MTT (3- (4,5-dimethylthiazol-2-yl) -2,5, -diphenyltetrazolium bromide) and crystal violet: cells in the absence of acai extract and PDT (control group); cells in the presence of acai extract and no light; and cells in the presence of acai extract and LED blue light (PDT groups). RESULTS: When using acai as a PS combined with blue LED (460 nm, 0.7466 cm2 , 1000 mW/cm2 ) and irradiation at 25, 50, and 100 J/cm2 , after 72 h, cell viability (p < 0.0001 vs. control, p = 0.0027 vs. 100 mg/ml açai group, p = 0.0039 vs. 40 mg/ml açai group, p = 0.0135 vs. 10 mg/ml açai group; One-Way ANOVA/Tukey) and proliferation (p < 0.05, One-Way ANOVA/Tukey) decreased. CONCLUSION: The acai in question is a potential photosensitizer (PS), with blue light absorbance and efficacy against head and neck tumor lines (SCC9).

Effects of systemic vascular photobiomodulation using LED or laser on sensory-motor recovery following a peripheral nerve injury in Wistar rats.

Peripheral nerve injury (PNI) is associated with considerable functional impairment. Photobiomodulation (PBM) has demonstrated positive effects regarding neuromuscular repair after PNI when applied locally to the nerve or injured muscle. However, the effects of systemic PBM with transcutaneous application over an important artery, which is also denominated vascular PBM (VPBM), remain unclear. The aim of the study was to compare the effects of VPBM with low-level laser (LLL) and light-emitting diode (LED) on gait, sensitivity and muscle morphology following a PNI. PNI was induced on Wistar rats using the sciatic nerve crushing technique. VPBM was performed over the rat's artery tail region with LED (850 nm, 40 mW, 3.2 J) and LLL (780 nm, 40 mW, 3.2 J). Gait functionality, mechanical (nociceptive) sensitivity, and morphology of the tibialis anterior muscle were evaluated at 7, 14, and 21 days after injury. An improvement in functional gait was shown in the VPBM-LLL group in all periods. Motor sensitivity was found after 14 days in the VPBM-LLL group. The left/right (L/R) muscle mass ratio revealed a reduction in muscle atrophy in the VPBM-LLL group at 7 days. Muscle fiber diameter increased in the VPBM-LED group at 14 days and increases in the cross-section area were found in the VPBM-LED and VPBM-LLL groups at 7 days. VPBM with both light sources (LED and LLL) positively modulated functioning and neuromuscular recovery following sciatic nerve injury in rats, with more pronounced results when using LLL.

Evaluation of intravascular irradiation of blood in children with sleep bruxism: Study protocol for a randomized controlled clinical trial.

BACKGROUND: The objective of this study will be to evaluate the effect of intravascular irradiation of blood (ILIB) combined with myofunctional exercises for sleep bruxism in pediatrics. METHODS: This study will be a randomized controlled clinical trial. A triage of individuals between 4 and 17 years old with a diagnosis of sleep bruxism will be carried out at the clinic of the Catholic University of Uruguay, and in a private office referred by different private care centers. The selected participants will be evaluated before and after treatment by means of questionnaires on bruxism, sleep quality and nocturnal oxygen saturation measurement. For this, 46 patients with sleep bruxism will be recruited, who will be divided into 2 groups: control group (CG), which will undergo an application of placebo ILIB and an orofacial myofunctional therapy (MFT) exercise protocol; and na ILIB group, which will carry out an active application of ILIB and an exercise protocol, this being once a week for 8 weeks. The laser treatment (808 nm) will be performed twice a week for 8 weeks. The values will be tested for normality by the Kolmogorov-Smirnov test. For the comparison between the groups, t test will be carried out, considering a level of significance of 0.5% (P < .05). DISCUSSION: Although local photobiomodulation (PBM), acupuncture PBM and physiotherapy have been studied in the treatment of bruxism, this is the first study to evaluate the effect of ILIB combined with myofunctional exercises for sleep bruxism in pediatrics.

Vascular photobiomodulation in the treatment of children with temporomandibular disorders: Study protocol for a randomized, controlled, blind, clinical trial.

BACKGROUND: This study aims to verify if the use of intravascular laser irradiation of blood (ILIB) influences the reduction of pain and increases the range of motion in opening and closing of the mouth in children and adolescents with temporomandibular disorders (TMD). METHODS: This will be a blind, randomized, and controlled clinical trial, which will be carried out on children between 6 and 12 years of age who enter the Catholic University of Uruguay, Faculty of Health Sciences, Postgraduate School, for treatment. To be included, children must present temporomandibular disorders, based on the diagnostic criteria will be the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Forty-five participants will be randomized to three groups: Group 1-ILIB with 2 sessions of 20 minutes for 12 weeks (n = 15); Group 2-Placebo laser application with 2 sessions of 20 minutes for 12 weeks (n = 15); Group 3-Control with no treatment (n = 15). Irradiation will be performed by continuous and direct transcutaneous application to the radial artery, by means of a bracelet that inserts the laser beam. The laser to be used is infrared, power 100 mW ± 20%, wavelength 808 nm ± 10 nm, continuous application. RDC/TMD and pain evaluated through a visual analog scale will be the outcome measures. DISCUSSION: Due to the low level of evidence, new studies are needed on the effect of ILIB in children with TMD.

Vascular photobiomodulation increases muscle fiber diameter and improves the gait during compensatory hypertrophy of plantar muscle in rats.

The local photobiomodulation (LPBM) has demonstrated positive effects during compensatory hypertrophy (CH) in skeletal muscle as a response to an overload. The aim was to compare the effects of the transcutaneous vascular photobiomodulation (VPBM) and the LPBM on muscle fiber size, gait functionality, and on mechanical sensitivity during the CH model in rats. VPBM was administered over the rat's main tail vein and LPBM was applied over the plantar muscle region. VPBM induced an increase in muscle fiber diameter and cross-sectional area (CSA) after 7 days. At 14 days, an increase in the fiber diameter was found in both irradiated groups. The VPBM and LPBM promoted the reestablishment of normal gait evaluated by the sciatic functional index after 14 days. No changes were found in the mechanical (nociceptive) sensitivity in VPBM and LPBM groups in comparison to the CH group but there was an increase in the nociceptive sensitivity in the CH groups in comparison to the control after 7 and 14 days. In conclusion, both PBM, vascular and local, were able to improve the muscle size and gait during the CH process with more pronounced effects when irradiation was performed systemically (VPBM).

Simultaneous red and infrared light-emitting diodes reduced pain in individuals with temporomandibular disorder: a randomized, controlled, double-blind, clinical trial.

The aim of the present study was to evaluate the effects of photobiomodulation (PBM) with the simultaneous use of red and infrared LEDs on pain and mandibular range of motion in individuals with temporomandibular disorder (TMD). Eighteen participants were randomly allocated to an LED group or control group. The device had 18 red LEDs (660 nm) and 18 infrared LEDs (850 nm), with a total power irradiated of 126 mW and 75.6 J per point. The device was placed in the regions of the temporomandibular joint (TMJ) and masticatory muscles once per day three times per week for 2 weeks. Pain intensity was measured using the visual analog scale (VAS). Mandibular range of motion was determined using digital calipers and considering different conditions (unassisted opening without pain, maximum opening with and without assistance, right and left lateral movements, and protrusion). Evaluations were performed before treatment, immediately after the first LED irradiation session and at the end of six sessions. A significant reduction in pain intensity was found in the LED group at the end of treatment compared to the control group (p < 0.001) as well as in the comparison between the pretreatment and end of treatment evaluations (p < 0.001). Regarding mandibular movements, no statistically significant differences between the LED group and control group were found at the end of treatment for any of the conditions analyzed or in the comparison between the beginning and end of treatment with LED. Photobiomodulation using a cluster with red and infrared LEDs induced a reduction in pain in individuals with temporomandibular disorder but did not alter mandibular range of motion in these individuals. Trial registration number: NCT03696706; retrospectively registered (ClinicalTrials.gov).

Effect of photobiomodulation on fatigue in individuals with relapsing-remitting multiple sclerosis: a pilot study.

Multiple sclerosis is an autoimmune disease of the central nervous system characterized by inflammation and destruction of the myelin sheath. Fatigue is one of the main symptoms of this disease, with a negative impact on quality of life and few treatment options. Photobiomodulation is used for several inflammatory conditions and may be beneficial for the treatment of fatigue in individuals with multiple sclerosis. Conduct a pilot study to analyze the effect of photobiomodulation on fatigue in individuals with relapsing-remitting multiple sclerosis. The participants were recruited from the UNINOVE Integrated Health Clinic and randomly allocated to two groups: group 1, administration of photobiomodulation (808 nm, 36 J for 360 s) under the tongue and group 2, administration of photobiomodulation over the radial artery. Fatigue was measured using the Modified Fatigue Impact Scale (MFIS). No significant differences were found regarding the total MFIS score or subscale scores (p < 0.05, two-way ANOVA). Photobiomodulation with the parameters employed in the present study had no effect on fatigue in individuals with multiple sclerosis. ClinicalTrials.gov Identifier: NCT03360487.

Effects of photobiomodulation in experimental spinal cord injury models: A systematic review.

This systematic review investigated the repercussions of photobiomodulation using low-level laser therapy (LLLT) for the treatment of spinal cord injury (SCI) in experimental models. Studies were identified from relevant databases published between January 2009 and December 2021. Nineteen original articles were selected and 68.4% used light at an infrared wavelength. There was a considerable variation of the power used (from 25 to 200 mW), total application time (8-3000 s) and total energy (0.3-450 J). In 79% of the studies, irradiation was initiated immediately after or within 2 h of the SCI, and treatment time ranged continuously from 5 to 21 days. In conclusion, LLLT can be an auxiliary therapy in the treatment of SCI, playing a neuroprotective role, enabling functional recovery, increasing the concentration of nerve connections around the injury site and reducing pro-inflammatory cytokines. However, there is a need for standardization in the dosimetric parameters.

Non-surgical interventions for the treatment of masticatory muscular spasticity in patients with cerebral palsy. Systematic review of randomized clinical trials.

INTRODUCTION: Muscle disorders caused by cerebral palsy (CP) can affect oral function. The treatment for masticatory muscle spasticity is important to minimize muscle hyperactivity and preclude oral damages. OBJECTIVES: To evaluate the efficacy and safety of non-surgical interventions for the treatment of masticatory muscle spasticity in CP patients. METHODS: A comprehensive search was performed in the following databases: MEDLINE, Embase, Cochrane Library, LILACS, BBO, PEDro, Clinicaltrials.gov and WHO/ICTRP, without date and language restrictions. Randomized controlled trials (RCT) evaluating non-surgical interventions were considered. Primary outcomes such as masticatory function and adverse events were planned to be assessed. The risk of bias assessment was performed using the Cochrane risk of bias tool. The certainty of the evidence was assessed using the GRADE approach. RESULTS: Three RCT assessing the effects of botulinum toxin, functional masticatory training and neuromuscular electrostimulation (NMES) were included. Evidence with a very low certainty showed: (i) no difference between botulinum toxin and placebo regarding maximum chewing strength, chewing efficiency and global oral health scale; (ii) improvement in masticatory function in favor of functional masticatory training versus conventional exercises, and (iii) in favor of strengthening exercises plus NMES versus placebo. CONCLUSIONS: There was insufficient evidence to support the use of botulinum toxin and masticatory muscle strengthening programs alone and associated with NMES for the treatment of masticatory muscle in patients with PC. The clinical decision must be individualized, and further studies are needed to support or refute the use of different non-surgical interventions for PC. PROSPERO register number CRD42020209761.

Histological and biochemical effects of preventive and therapeutic vascular photobiomodulation on rat muscle injury.

The intravascular or transcutaneous application of photobiomodulation (PBM) over blood vessels (vascular photobiomodulation, VPBM) has been used for the treatment of inflammatory and chronic conditions with promising systemic results. This study evaluated the VPBM effects on a model of muscle regeneration after acute injury and compared the outcomes of preventive and therapeutic VPBM. Transcutaneous VPBM was administered over the rat's main tail vein. Serum levels of creatine kinase (CK), aspartate aminotransferase (AST), and lactate were evaluated and muscles were processed for macroscopic and microscopic analysis. Preventive and therapeutic VPBM led to decreased inflammatory infiltrate, edema, and myonecrosis but with an increase in immature muscle fibers. CK, AST, and lactate levels were lower in the groups treated with VPBM (lowest concentrations in preventive VPBM application). Preventive and therapeutic VPBM were capable of exerting a positive effect on acute muscle injury repair, with more accentuated results when preventive VPBM was administered.

The effects of photobiomodulation using LED on the repair process of skin graft donor sites.

The benefits of photobiomodulation (PBM) applied to wounds are well-described in the literature; however, its effects in skin graft donor sites have been poorly studied. The aim of this study is to evaluate the effects of LED PBM on re-epithelialization and wound quality of the skin donor site and on pain during repair process. This is a case series study that part of the patients received standard treatment and the others received standard treatment combined with PBM. Data collection was performed at the Burn Unit at a Public Hospital, Brazil. The study had 21 participants and 25 donor sites, 13 in the control group (conventional treatment with Membracel® bandage) and 12 in the experimental group (Membracel® + LED). Irradiation parameters were 1.53 J/cm2, 2.55 mW/cm2, 660 nm, 600 s in the immediate postoperative period as well as on the 1st, 3rd, 5th, and 7th days postoperatively. Pain was measured using the visual analog scale. The Bates-Jensen scale was used to monitor the re-epithelialization process and measurements were performed of donor skin sites in the postoperative period. Quantitative variables were expressed as mean ± standard deviation or median and interquartile range [p25; p75]. The comparison of the distribution of these variables between groups was performed using the Mann-Whitney test. No differences between groups were found for re-epithelialization time, area or quality of the wound. Regarding pain, a significant reduction was found on the 5th postoperative day in the experimental group compared to the control group. PBM did not induce changes in the re-epithelialization period, wound area or wound quality scores of the Bates-Jensen Scale but did induce a reduction in pain compared to the group treated with Membracel® alone.

Effect of photobiomodulation combined with physical therapy on functional performance in children with myelomeningocele: A protocol randomized clinical blind study.

INTRODUCTION: Myelomeningocele is a severe type of spina bifida, resulting from improper closure of the neural tube. This condition drastically affects the structures of the spinal cord resulting in deficiencies. The combination of these deficiencies results in an overall decrease in mobility and functional participation amongst this population. Physiotherapy plays an essential role in rehabilitating people with MMC. The current literature shows that resources such as photobiomodulation (PBM) may support the rehabilitation of neurological conditions. The aim of the proposed study is to evaluate the effects of photobiomodulation (PBM) combined with physical therapy on functional performance in children with low lumbosacral myelomeningocele. MATERIALS AND METHODS: This is a protocol randomized clinical blind study, that will include 30 individuals of both sexes, aged between 5 to 8 years, diagnosed with low and sacral lumbar myelomeningocele and capable of performing the sit-to-stand task. The participants will be randomly assigned into two treatment groups: PBM + physiotherapeutic exercises and sham PBM + physiotherapeutic exercises. Irradiation will be carried out with light emitting diode (LED) at a wavelength of 850 nm, energy of 25 J per point, 50 seconds per point and a power of 200 mW. The same device will be used in the placebo group but will not emit light. Muscle activity will be assessed using a portable electromyograph (BTS Engineering) and the sit-to-stand task will be performed as a measure of functioning. Electrodes will be positioned on the lateral gastrocnemius, tibialis anterior and rectus femoris muscles. The Pediatric Evaluation of Disability Inventory will be used to assess functional independence. Quality of life will be assessed using the Child Health Questionnaire-Parent Form 50. Changes in participation will be assessed using the Participation and Environment Measure for Children and Youth. The data will be analyzed with the aid of GraphPad PRISM. DISCUSSION: The results of this study can contribute to a better understanding of the effectiveness of PBM on functioning and quality of life in children with myelomeningocele. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04425330.

The Effect of Photobiomodulation on Analgesia During Childbirth: A Controlled and Randomized Clinical Trial.

Background: Pain during labor can be a barrier when choosing vaginal delivery. In an attempt to relief pain during labor, several pharmacological and nonpharmacological methods are proposed. Objective: To assess the effect of light-emitting diode (LED) photobiomodulation on analgesia during labor. Methods: A clinical trial was conducted with 29 women who were divided into two groups: G1 (experimental group-LED) and G2 (control group-hot shower). In the experimental group, an LED plate with red and infrared merged [red 660 ± 20 nm, 5 mW/cm2, 3 J per LED (108 J) and infrared 850 ± 20 nm, 5 mW/cm2, 3 J per LED (108 J), total energy = 216 J] was placed on the subjects' dorsal region, at the level of T10 to S4, for 10 min, with the plate automatically turning off. Hot shower at controlled temperature was offered for 30 min. To verify the effect of LED on analgesia during labor, the following variables were assessed: (1) perception of pain, (2) fetal well-being assessed by cardiotocography or intermittent auscultation of fetal heart rate, (3) Apgar score at minutes 1 and 5 after birth, and (4) labor duration. Results: There was a statistically significant difference (p < 0.05) in pain reduction evidenced by a millimetric visual scale, before and after application on G1-LED (7.92 ± 1.78). Regarding the other variables, there was no statistical difference between the groups when comparing fetal well-being, Apgar score and labor duration. Conclusions: It is concluded that LED can be considered an alternative, since it caused pain reduction without changing other parameters during labor, compared with hot shower, a method included in hospital protocols, proving to be safe. Clinical Trial Registration number: NCT03496857.

Evaluation of the Preventive Effect of Photobiomodulation on Orofacial Discomfort in Dental Procedures: A Randomized-Controlled, Crossover Study and Clinical Trial.

Background: Orofacial pain has been a prevalent symptom in the worldwide population, which may cause restrictions in daily activities and, consequently, have a great impact on the well-being of affected individuals. Photobiomodulation using light sources, such as low-level laser or light emitting diodes, with different wavelengths, has been widely used in the last years, in addition to being a noninvasive, low-cost resource and reducing pain. Objective: This study aimed at evaluating the effect of photobiomodulation as a protocol treatment to prevent facial muscle discomfort after long-term clinical procedures. Methods: The volunteers were randomized and allocated as follows: laser (n = 16) and placebo (n = 16) groups, following a crossover study design. The laser parameters were as following: 786 nm wavelength, 9 J per point, and 100 mW power of 2.393 W/cm2 irradiance. The discomfort was induced by simulating a 50-min dental procedure (with bilateral mouth open), and the pain scale (assessed bilaterally), tiredness, and temperature measurement through thermography were used for analysis. Results: The results showed a significant lower pain and tiredness in the laser group. Also, the results showed a statistically significant valid temperature change between the groups at times: T1, T40, and T50. Conclusions: According to our results, photobiomodulation showed a positive effect on the face musculature in patients submitted to the treatments, reducing pain and improving the subjective perception of exertion.

Effect of Photobiomodulation in Lipopolysaccharide-Treated Myoblasts.

Objective: To evaluate the effect of photobiomodulation (PBM) on cell viability, synthesis of nitric oxide (NO), and interleukin (IL)-6 inflammatory cytokine production in myoblasts cultured in the presence of lipopolysaccharides (LPSs). Methods: C2C12 myoblasts were treated with LPS and PBM using different parameters (wavelength: 780 nm; beam spot: 0.04 cm2; power output: 10 or 40 mW; energy density: 5 or 20 J/cm2; and 20-sec exposure time). Nonirradiated cells were used to the control group. Results: An increase in cell viability was found in both LPS groups in comparison with the control. PBM with the higher power output (40 mW) induced a reduction in cell viability. PBM also modulated the synthesis of NO in the myoblasts, but did not alter the expression of IL-6. Conclusions: Based on these findings, PBM is capable of modulating the cell viability and the production of NO in LPS-treated myoblasts and it is, therefore, a possible tool for the treatment of muscle injury caused by infection.