Photobiomodulation on isolated mitochondria at 810 nm: first results on the efficiency of the energy conversion process.

In this paper the photobiomodulation on isolated mitochondria of bovine liver is studied as a thermodynamic process of conversion of energy. This analysis is conducted by considering a particular set-up for the photobiomodulation experiments of interest. It allows, in particular, the computation of the electromagnetic field and the related energetic quantities in the stimulated organelles. The measurements of the excess of biochemical power density produced by the illuminated mitochondria are performed at regular time intervals after the experiments. The calculations and the measurements finally allow us to obtain the first results on the efficiency of the process of conversion of electromagnetic energy into excess of biochemical energy released by the isolated organelles.

Adjunctive use of laser biostimulation with nonsurgical periodontal therapy: a split-mouth, randomized, case-control study in diabetic and nondiabetic periodontitis patients.

Background/aim: Laser biostimulation therapy (LBT) is suggested to have positive effects on periodontal healing. This study evaluated LBT with nonsurgical periodontal therapy (NSPT) in diabetes mellitus (DM) and systemic health (SH) conditions. Materials and methods: Thirty periodontitis patients (15 with DM and 15 with SH) were included in the study, which had a split-mouth design, by applying LBT in the mouth of the same systemic condition. Thus, 4 study groups were formed, as 1) NSPT - DM: NSPT alone in DM, 2) NSPT + LBT - DM: NSPT + LBT application in DM, 3) NSPT - SH: NSPT alone in SH, and 4) NSPT + LBT - SH: NSPT + LBT application in SH. NSPT was performed on days 15, 30, 37, 44, 51, 58, and 65. LBT was performed 6 times on days 30, 37, 44, 51, 58, and 65 with an Nd:YAG laser. The plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment level (CAL) were assessed as the clinical parameters and recorded at baseline and days 30, 37, and 72. Gingival crevicular fluid levels of interleukin 1 beta (IL-1ß) and IL-10 were evaluated by ELISA as the biochemical parameters at baseline and on days 30, 37, and 72. Results: Clinical parameters had improved in all of the groups on day 72 (p < 0.01). PPD and CAL improved more in the DM group with NSPT and LBT group than in the DM group with NSPT without LBT on day 37 (p < 0.05). IL-1ß decreased and IL-10 increased in all of the groups on day 72 (p < 0.01). This change was more evident in the DM group with NSPT and LBT than in the DM group with NSPT without LBT on day 7 (p < 0.05). Conclusion: These results revealed the short-term impacts of LBT on periodontal healing, which return to ineffectiveness with repeated irradiation. Therefore, it may be speculated that LBT via the protocol herein may have a short-term antiinflammatory contribution to NSPT, only in impaired healing conditions such as DM.

Efficacy of root coverage with the use of the conventional versus laser-assisted flap technique with platelet-rich fibrin in class I and class II gingival recession: A randomized clinical trial.

BACKGROUND: The coronally advanced flap (CAF) technique is the preferred option in treating recession defects, especially when the attached gingiva is adequate. A laser-assisted vestibular releasing incision after surgery could enhance the outcome. Platelets, when used as adjunctive treatment, have shown good results. However, laser biostimulation post-surgery has not been studied. OBJECTIVES: The present study compared the benefits of using the conventional and laser-assisted flap technique with platelet-rich fibrin (PRF) in the treatment of class I and class II gingival recession. MATERIAL AND METHODS: The study included 24 subjects, both males and females. The participants, diagnosed with Miller's class I and II gingival recession, were categorized into 2 groups: group A (n = 12) treated with CAF and PRF; and group B (n = 12) treated with laser-assisted CAF and PRF. Root coverage (RC), the probing depth (PD), the clinical attachment loss (CAL), and the keratinized tissue width (KTW) were assessed preand 6 months postoperatively. The wound healing index (WHI) and the visual analog scale (VAS) scores were assessed 1 week post-surgery. RESULTS: Most clinical parameters improved significantly within the groups at 6 months postoperatively as compared to baseline (p < 0.05), except for PD and percentage root coverage (PRC). However, when intergroup comparisons were made, it was observed that both groups performed equally well and the differences between them were not significant. CONCLUSIONS: Both treatment modalities improved the clinical parameters post-surgery. However, further trials are warranted to affirm the benefits of the laser-assisted CAF technique.

Laser Biostimulation Induces Wound Healing-Promoter ß2-Defensin Expression in Human Keratinocytes via Oxidative Stress.

The innate immune system is the first line of defense of the body composed of anatomical barriers, such as skin and mucosa, as well as effector cells, antimicrobial peptides, soluble mediators, and cell receptors able to detect and destroy viruses and bacteria and to sense trauma and wounds to initiate repair. The human ß-defensins belong to a family of antimicrobial small cationic peptides produced by epithelial cells, and show immunomodulatory and pro-healing activities. Laser biostimulation is a therapy widely used to contrast microbial infection and to accelerate wound healing through biological mechanisms that include the creation of oxidative stress. In this paper, we explored laser biostimulation's ability to modulate the production of two ß-defensins, hBD-1 and hBD-2, in human keratinocytes and whether this modulation was, at least in part, oxidative-stress-dependent. Human spontaneously immortalized keratinocytes (HaCaT) were stimulated using laser irradiation at a 980 nm wavelength, setting the power output to 1 W (649.35 mW/cm2) in the continuous mode. Cells were irradiated for 0 (negative control), 5, 10, 25 and 50 s, corresponding to an energy stimulation of 0, 5, 10, 25 and 50 J. Positive control cells were treated with lipopolysaccharide (LPS, 200 ng/mL). After 6 and 24 h of treatment, the cell conditioned medium was collected and analyzed via ELISA assay for the production of hBD-1 and hBD-2. In another set of experiments, HaCaT were pre-incubated for 45 min with antioxidant drugs-vitamin C (Vit. C, 100 µM), sodium azide (NaN3, 1 mM); ω-nitro-L-arginine methyl ester (L-NAME, 10 mM) and sodium pyruvate (NaPyr, 100 µM)-and then biostimulated for 0 or 50 s. After 6 h, the conditioned medium was collected and used for the ELISA analysis. The hBD-1 and hBD-2 production by HaCaT was significantly increased by single laser biostimulation after 6 h in an energy-dependent fashion compared to basal levels, and both reached production levels induced by LPS. After 24 h, only hBD-2 production induced by laser biostimulation was further increased, while the basal and stimulated hBD-1 levels were comparable. Pre-incubation with antioxidative drugs was able to completely abrogate the laser-induced production of both hBD-1 and hBD-2 after 6 h, with the exception of hBD-1 production in samples stimulated after NaN3 pre-incubation. A single laser biostimulation induced the oxidative-stress-dependent production of both hBD-1 and hBD-2 in human keratinocytes. In particular, the pro-healing hBD-2 level was almost three times higher than the baseline level and lasted for 24 h. These findings increase our knowledge about the positive effects of laser biostimulation on wound healing.

Rare clinical case report of a contralateral effect of laser biostimulation on the bone regeneration.

This paper describes a unique clinical case of peri-implantitis treated by a laser biostimulation in one side of maxilla and the effect extended to contralateral side in the maxilla. This indicates that low level laser therapy treatment may have some degree of bilateral effects within the orofacial region.

Low-level laser therapy (LLLT) improves alveolar bone healing in rats.

The main objective of the present study was to evaluate the effect of low-level laser therapy (LLLT) in enhancing bone healing in irradiated alveolus post-tooth extraction. Sixty male Wistar rats (180 ± 10 g) were used in the present study. The left maxillary first molars were extracted, and the alveolar region was irradiated by diode laser device (GaAlAs) immediately after extraction and for more 3-day daily applications. The animals were randomly assigned into two groups: control group (n = 30, with left maxillary molar extraction-CG) and experimental group (n = 30, with tooth extraction and low-level laser therapy applied to the dental alveolus for 42 s-EG). These groups were divided into subgroups (five rats per subgroup) according to the observation time point-1, 2, 3, 5, 7, and 10 days-post-tooth extraction. The maxillary bone was separated, and the specimens were stained with hematoxylin and eosin, Masson's trichrome, and picrosirius red and immunohistochemistry for RUNX-2. Parametric and nonparametric tests were used with a significance level of 5%. LLLT accelerated bone healing with mature collagen fiber bundles and early new bone formation. Histomorphometric analysis revealed an increase of osteoblast (RUNX-2) and osteoclast (TRAP) activity and in the area percentage of cancellous bone in the lased alveolus compared to the control group. This increase was statistically significant (p < 0.05). Application of LLLT with a GaAlAs diode laser device enhanced bone healing and mineralization on alveolar region.

Comparative efficacy of topical aloe vera and low-level laser therapy in the management of oral lichen planus: a randomized clinical trial.

This randomized clinical trial aimed to compare the efficacy of topical aloe vera with low-level laser therapy in patients with oral lichen planus (OLP). A randomized, parallel arm, single-blind study comprising of 60 patients with OLP was randomly divided into two groups. Group A was given topical aloe vera extract gel applied thrice daily for 2 months, and group B was given low-level laser therapy (LLLT) at 980 nm twice weekly for 2 months. Both groups were followed up for 9 months. Patients were assessed for various parameters according to the Escudier scale at baseline, after treatment at 9 months. Results were assessed using the McNemar-Bowker test and the Mann-Whitney U test. Both individual groups showed significant (p < 0.05) results at the end of the treatment period (0-2 months) and the follow-up period (2-7 months). Intergroup comparison showed significant results in the laser group (reduction of VAS by 44.1%, site score by 24.6%, and activity score by 50%) as compared with the aloe vera group (reduction of VAS by 26.7%, site score by 9.2%, and the activity score by 26%) in the treatment period. In the follow-up period, both groups showed insignificant differences in comparison to each other. Within the limitations of the study, LLLT was more effective as compared with topical aloe vera in managing oral lichen planus during the active treatment time, while both were equally effective during the follow-up period. The clinical study was registered under the Clinical Trials Registry India with the registration number CTRI/2018/04/013147.

Usefulness of high-frequency ultrasound to assess the healing progress of shin ulcers.

INTRODUCTION: As the average lifespan becomes longer, the number of cases of chronic shin ulcers is rising, which is slowly becoming a societal problem. Currently, there no methods for objective evaluation of ulcer healing process. AIM OF THE STUDY: The aim of the study was to assess the use of high-frequency ultrasound to monitor the healing of shin ulcers subjected to laser biostimulation. MATERIAL AND METHODS: The study included 8 patients (4 men and 4 women) aged from 46 to 81 years with 9 shin ulcers in whom the healing process did not progress within 8 weeks despite effective causal treatment. The ulcers were subjected to laser biostimulation. The induced changes were monitored using high-frequency ultrasound and photographic records. Ultrasound examination was used to assess the depth of ulceration and the thickness of granulation tissue, migrating epidermis, subepidermal low-echogenic band (SLEB) and epidermis in the immediate vicinity. The wound severity index and ulcer vascularity were also assessed. RESULTS: As a result of laser therapy, in 7 out of 9 cases the ulcers healed completely and in the remaining 2 cases ulcer size was reduced. During the ulcer healing process induced by laser therapy, ultrasound examination revealed decreasing ulcer depth, wound severity index and SLEB thickness. Granulation tissue increased in thickness and there was an epidermal formation effect (newly formed epidermis was much thicker than the one surrounding the wound and became thicker as a result of laser therapy sessions). During the healing of ulcers induced by laser therapy no significant changes were observed in ulcer vascularity and thickness of the surrounding epidermis. CONCLUSIONS: High-frequency ultrasound is a useful technique for the imaging of leg ulcers. It allows one to monitor their healing process induced by laser biostimulation. Further research on the subject needs to be pursued.

Laser therapy increases the proliferation of preosteoblastic MC3T3-E1 cells cultured on poly(lactic acid) films.

This study aimed to verify the efficacy of low-level laser irradiation (LLLI) on the proliferation of MC3T3-E1 preosteoblasts cultured on poly(lactic acid) (PLA) films. The produced films were characterized by contact angle tests, scanning electron microscopy (SEM), atomic force microscopy, differential scanning calorimetry, and X-ray diffraction. The MC3T3-E1 cells were cultured as three different groups: Control-cultured on polystyrene plastic surfaces; PLA-cultured on PLA films; and PLA + Laser-cultured on PLA films and submitted to laser irradiation (660 nm; 30 mW; 4 J/cm2 ). Cell proliferation was analyzed by Trypan blue and Alamar blue assays at 24, 48, and 72 h after irradiation. Cell viability was assessed by Live/Dead assay, apoptosis-related events were evaluated by Annexin V/propidium iodide (PI) expression, and cell cycle events were analyzed by flow cytometry. Cell morphology on the surface of films was assessed by SEM. Cell counting and biochemical assay results indicate that the PLA + Laser group exhibited higher proliferation (p < 0.01) when compared with the Control and PLA groups. The Live/Dead and Annexin/PI assays indicate increased cell viability in the PLA + Laser group that also presented a higher percentage of cells in the proliferative cell cycle phases (S and G2/M). These findings were also confirmed by the higher cell density observed in the irradiated group through SEM images. The evidence from this study supports the idea that LLLI increases the proliferation of MC3T3-E1 cells on PLA surfaces, suggesting that it can be potentially applied in bone tissue engineering.

Effect of 808 nm Semiconductor Laser on the Stability of Orthodontic Micro-Implants: A Split-Mouth Study.

BACKGROUND: To evaluate the effect of photobiomodulation (PBM) on orthodontic micro-implants (n = 44; 14 women, 8 men). METHODS: PBM with 808 nm diode laser was applied immediately, 3, 6, 9, 12, 15, and 30 days post the implantation. Results were assessed within same time frames and additionally after 60 days to check for implants stability using the Periotest device. Patients pain experiences following the first day post-treatment and potential loss of micro-implants after 60 days were recorded. The procedure involved insertion of mini-implants in the maxilla for the laser group (L, n = 22) and negative control group (C, n = 22). Irradiation was carried buccally and palatally with respect to the maxillary ridge (2 points). The energy per point was 4 J (8 J/cm2), total dose was 56 J. RESULTS: Patients did not report significant differences in terms of pain experiences comparing the L and C groups (p = 0.499). At 30 days post-treatment, higher secondary stability of implants was observed in the laser group (Periotest Test Value, PTV 6.32 ± 3.62), in contrast to the controls (PTV 11.34 ± 5.76) (p = 0.004). At 60 days post-treatment, significantly higher stability was recorded in the laser group (PTV 6.55 ± 4.66) compared with the controls, PTV (10.95 ± 4.77) (p = 0.009). Conclusions: Application of the 808 nm diode laser increased secondary micro-implant stability.

Enhancement of Healing of Periodontal Intrabony Defects Using 810 nm Diode Laser and Different Advanced Treatment Modalities: A Blind Experimental Study.

BACKGROUND: Low-level laser therapy (LLLT) in the early stage of bone healing was demonstrated as a positive local biostimulative effect. It was also shown that platelet-rich fibrin (PRF) and nanohydroxyapatite alloplast (NanoHA) are effective in treating periodontal intrabony defects. AIM: The study aimed to evaluate the combined effects of LLLT (810 nm), PRF and NanoHA on induced intrabony periodontal defects healing. MATERIAL AND METHODS: The study was conducted on 16 defects in 8 adult male rabbits (n = 16) divided into 4 groups; Control non-treated group (C), laser irradiated control group (CL), PRF+NanoHA graft (NanoHA-Graft+PRF) treated group and laser irradiated and treated group (NanoHA-Graft+PRF+L). CT radiography was made at baseline, 15 and 30 days later. The defects were induced in the form of one osseous wall defects of 10 mm height, 4 mm depth between the 1st and the 2nd molars using a tapered fissure drill coupled to a high-speed motor. Statistical analysis was done using ANOVA. RESULTS: (NanoHA-Graft+PRF+L) group significantly produced bone density higher than C, CL and NanoHA-G+PRF alone. CONCLUSION: The combination of LLLT+PRF+NanoHA as a treatment modality induced the best results in bone formation in the bone defect more than LLLT alone or PRF+NanoHA alone.

Comparative Evaluation of Effect of Lasers and Biodentine in Dentine Regeneration: A Clinical Study.

AIM: To compare and evaluate the effect of different liners separately and in combination with lasers that is resin modified glass-ionomer cement (RMGIC), Laser+RMGIC, Biodentine, Laser+Biodentinein the treatment of deep carious lesions. MATERIALS AND METHODS: Forty patients with deep caries indicated for pulp capping were selected. Curative procedure including the cavity preparation with maximal removal of softened dentine using spoon excavator, slow speed handpiece with round burs was performed. Patients were divided into four groups with 10 patients in each group In group A RMGIC liner, group B laser biostimulation followed by RMGIC liner, group C biodentine liner, group D laser biostimulation followed by Biodentine liner were placed in the cavity after caries removal. Cavities were temporarily restored with IRM for 8 weeks. After 8 weeks, liners in each group were removed, and cavities were permanently restored lower half of the cavity with a layer of flowable Z350 XT composite, and then the remaining half of the cavity with P60 filled composites (3 M ESPE, USA) in all the groups. The observation period was 12 months. RESULTS: All the patients showed a positive response to cold test and electric pulp test at 3 months, 6 months, 12 months follow-up. In group A (RMGIC) two patients and in group B (Laser+Biodentine) three patients did not return back for the follow-up. To standardize the samples, seven patients were selected from each group with a total of 28 samples included in the study (n = 7) and statistical analysis was done using analysis of variance (ANOVA) test. The mean for the total amount of dentine deposited after 12 months was highest in: Group D-(Laser+Biodenitne) 0.32 mm > Group C-(Biodentine) 0.25 mm > Group B-(Laser+RMGIC) 0.10 > Group A-(RMGIC) 0.07 mm Conclusion: Within the limitation of the present study the following conclusion was drawn: • Lasers and biodentine are good indirect pulp capping agents • Laser has an additional effect on the tertiary dentine formation. CLINICAL SIGNIFICANCE: Lasers with antibacterial effect penetrate into dentinal tubules and accelerate the rate of dentin bridge formation in deep carious lesions.

The influence of low-intensity laser therapy on bone healing.

OBJECTIVE: Low-intensity laser therapy (LILT) is defined to supply direct biostimulative light energy to the cells. While several studies have demonstrated that LILT has stimulating effects on bone cells and can accelerate the repair process of the bone, others reported delayed fracture healing or no effects after LILT. The aim of this article was to review the studies evaluating the biomodulation effects of LILT on bone-derived stem cells. MATERIALS AND METHODS: To access relevant articles, searching in three electronic databases including PubMed, Google Scholar and Science Direct was conducted until April 2012. The key words used were low-level laser, low-intensity laser, low-power laser therapy, stem cell, bone marrow stem cell, bone and osteoblast. The articles that met the eligibility criteria were included in this review of literature. RESULTS: Twenty-five relevant articles (13 in vitro and 12 animal studies) were included. Eleven in vitro studies showed positive results with regard to acceleration of cell proliferation and differentiation. All animal studies showed improved bone healing in sites irradiated with low-intensity laser. CONCLUSION: Based on the results of the reviewed articles, low intensity laser therapy can accelerate bone healing in extraction sites, bone fracture defects and distraction osteogenesis, provided proper parameters were applied.

Efecto de la terapia láser de baja potencia sobre el hueso alveolar dañado / The low level laser therapy effect on alveolar bone damaged

La terapia con láser de baja potencia ha demostrado tener propiedades analgésicas antiinflamatorias, bioestimulantes y promotoras de la respuesta tisular al daño. El propósito de este estudio fue determinar el efecto que el láser de baja potencia tiene sobre el hueso alveolar dañado. Se utilizaros 13 ratas Sprage Dawley, en las cuales se realizó una lesión estandarizada del hueso alveolar, posterior a lo cual una muestra aleatoria de 7 ratas fue sometida a un protocolo de irradiación de 6 J/cm2, tres veces por semana durante cuatro semanas. Las muestras obtenidas del sitio lesionado en ratas expuestas y no expuestas a la terapia fueron procesadas para hematoxilina eosina, contabilizándose el número de osteonas al microscopio óptico con aumento de 40x. Los resultados muestran un aumento en el número de osteonas en el grupo irradiado, diferencia que resultó estadísticamente significativa (p<0,01), con una alta fuerza de asociación estadística (O.R=5,6 ). Estos resultados sugieren que la terapia láser de baja potencia favorece la respuesta del hueso alveolar dañado.

The Low Level Laser Therapy (LLLT) has demostrated to have analgesic, antiinflamatory, bioestimulant and promoters from the tissues responses properties to the damage. The purpose of this study was determinate the Low Level Laser Therapy effect in the damaged alveolar bone. Thirteen Sprage Dawley rats were used. Total number of animals alveolar bones a standarized lesion was made, later an aleatory sample of seven rats was subjected to the irradiation protocol 6 J/cm², three times per week during four weeks. The obtained samples of the injured area, of exposed and not exposed rats to the laser therapy were processed for hematoxilin & eosin, being the osteon number count by optic microscope with increase of 40x. The result show an increase in the osteon number in the irradiated group, this differentiated was statistically significant (p<0.01), whit a high strength of statistical association (OR=5.6). These result suggest that the therapy laser of low power favors the answer of the damaged alveolar bone.

Efecto de la Aplicación de Láser de Baja Potencia Sobre la Mucosa Oral Lesionada / Effect of the Low-power Laser on the Oral Mucous Injured

La utilización del láser ha tenido una constante evolución y desarrollo. Se ha comprobado en numerosos estudios los efectos bioestimulantes que la irradiación láser de baja potencia produce al interactuar con los tejidos y células. Este estudio pretende determinar la existencia de diferencias morfológicas en la mucosa oral lesionada, posterior a la irradiación con láser de baja potencia, a través de cambios en la densidad vascular del plexo subpapilar de la mucosa oral. Se utilizaron 15 ratas Sprague Dawley, las cuales se dividieron en tres grupos. A la totalidad de los animales se les lesionó la mucosa oral, en la zona media del frenillo labial inferior. El grupo I se tomó como control; al grupo II se le aplicó láser de baja potencia sobre la mucosa oral inmediatamente realizada la lesión, luego, a las 24 y 48 horas, en una dosis de 6 Joule/cm² por aplicación; al grupo III se le aplicó láser de baja potencia en una dosis única de 18 Joule/cm² inmediatamente efectuada la lesión. La unidad de muestra y análisis fueron los cortes histológicos obtenidos de la sección de la mucosa oral lesionada. Los resultados muestran una mayor densidad vascular en el grupo II con respecto a los grupos I y III, con una densidad promedio de 4,07 vasos sanguíneos/25mm², mientras el grupo I de 2,47 vasos sanguíneos/25mm² y el grupo III de 1,87 vasos sanguíneos/25mm². No se observó diferencia entre las densidades obtenidas para los grupos I y III. Estos resultados indican que la aplicación de láser de baja potencia en dosis baja produce un aumento en la densidad vascular en la mucosa oral lesionada.

The laser use has had a constant evolution and development; the bioestimulantion effects have been verified in numerous studies that the irradiation laser of fall promotes produces on having interacted with cells and tissues This study tries to determine the morphologic differences in the oral mucous injured, after the application of low-level laser, across changes in the vascular density of the subpapilar plexus of the mucous oral. Fifteen Sprague Dawley mice were used, which formed three groups, in the total number of animals the oral mucous was injured, in the average zone of the labial low frenum. Group I was taken as a control; in group II a low-level laser was applied on the mucous immediately the oral injury, then, at 48 after 24 hours in a dose of 6 Joule/cm² for application; Group III a low-level laser in a single dose of 18 Joule/cm² was applied immediately the oral injury. The unit of sample and analysis they were the histological cuts obtained of the section of the oral mucous injured. The results show a major vascular density in the group the II with regard to the group I and the III, with a density I mediate of 4,07 vassels/25mm², while the group I of 2,47 vassels/25mm² and group II of 1,87 vassels/25mm². No find differences between groups I and III. These results indicate that the application of low-level laser in low dose originate an increase in the vascular density in the oral mucous injured.