Photons Induce Vesicular Exocytotic Release of Glutamate in a Power-Dependent Way.

Increasing evidence indicates that photobiomodulation, based on tissue irradiation with photons in the red to near-infrared spectrum, may be an effective therapeutic approach to central nervous system disorders. Although nervous system functionality has been shown to be affected by photons in animal models, as well as in preliminary evidence in healthy subjects or in patients with neuropsychiatric disorders, the mechanisms involved in the photobiomodulation effects have not yet been clarified. We previously observed that photobiomodulation could stimulate glutamate release. Here, we investigate mechanisms potentially involved in the glutamate-releasing effect of photons from adult mouse cerebrocortical nerve terminals. We report evidence of photon ability to induce an exocytotic vesicular release of glutamate from the terminals of glutamatergic neurons in a power-dependent way. It can be hypothesized that photobiomodulation, depending on the potency, can release glutamate in a potentially neurotoxic or physiological range.

A Narrative Review on Oral and Periodontal Bacteria Microbiota Photobiomodulation, through Visible and Near-Infrared Light: From the Origins to Modern Therapies.

Photobiomodulation (PBM) consists of a photon energy transfer to the cell, employing non-ionizing light sources belonging to the visible and infrared spectrum. PBM acts on some intrinsic properties of molecules, energizing them through specific light wavelengths. During the evolution of life, semiconducting minerals were energized by sun radiation. The molecules that followed became photoacceptors and were expressed into the first proto-cells and prokaryote membranes. Afterward, the components of the mitochondria electron transport chain influenced the eukaryotic cell physiology. Therefore, although many organisms have not utilized light as an energy source, many of the molecules involved in their physiology have retained their primordial photoacceptive properties. Thus, in this review, we discuss how PBM can affect the oral microbiota through photo-energization and the non-thermal effect of light on photoacceptors (i.e., cytochromes, flavins, and iron-proteins). Sometimes, the interaction of photons with pigments of an endogenous nature is followed by thermal or photodynamic-like effects. However, the preliminary data do not allow determining reliable therapies but stress the need for further knowledge on light-bacteria interactions and microbiota management in the health and illness of patients through PBM.

Near-Infrared 810 nm Light Affects Porifera Chondrosia reniformis (Nardo, 1847) Regeneration: Molecular Implications and Evolutionary Considerations of Photobiomodulation-Animal Cell Interaction.

Chemotrophic choice as a metabolic source of energy has characterised animal cell evolution. However, light interactions with animal cell photoacceptors that are able to increase energetic metabolism (photo-biomodulation (PBM)) have been previously described. In the present study, we cut three specimens of Chondrosia reniformis into four equal parts (12 fragments), and we irradiated the regenerating edge of six fragments with the previously characterised 810 nm near-infrared light, delivered at 1 W, 60 J/cm2, 1 W/cm2, and 60 J in a continuous-wave mode for 60 s through a flat-top hand-piece with a rounded spot-size area of 1 cm2. Six fragments were irradiated with 0 W for 60 s as the controls. We performed irradiation at the time 0 h and every 24 h for a total of five administrations. We monitored the regeneration process for five days (120 h) in aquaria by examining the macroscopic and histological changes. We analysed the gene expression profile of the inflammatory processes, apoptosis, heat stress, growth factors, and collagen production and determined oxidative stress enzyme activity and the total prokaryotic symbiont content. PBM sped up C. reniformis regeneration when compared to the controls. Particularly, transforming growth factor TGF3 and TGF6 upregulation during the early phase of regeneration and TGF5 upregulation 120 h postinjury in the irradiated samples supports the positive effect of PBM in sponge tissue recovery. Conversely, the expression of TGF4, a sponge fibroblast growth factor homologue, was not affected by irradiation, indicating that multiple, independent pathways regulate the TGF genes. The results are consistent with our previous data on a wide range of organisms and humans, suggesting that PBM interaction with primary and secondary cell targets has been conserved through the evolution of life forms.

The effects of 808-nm near-infrared laser light irradiation on actin cytoskeleton reorganization in bone marrow mesenchymal stem cells.

Tailoring the cell organelles and thus changing cell homeostatic behavior has permitted the discovery of fascinating metabolic features enabling enhanced viability, differentiation, or quenching inflammation. Recently, photobiomodulation (PBM) has been accredited as an effective cell manipulation technique with promising therapeutic potential. In this prospective, in vitro results revealed that 808-nm laser light emitted by a hand-piece with a flat-top profile at an irradiation set up of 60 J/cm2 (1 W, 1 W/cm2; 60 s, continuous wave) regulates bone marrow stromal cell (BMSC) differentiation toward osteogenesis. Considering the importance of actin cytoskeleton reorganization, which controls a range of cell metabolic activities, comprising shape change, proliferation and differentiation, the aim of the current work is to assess whether PBM therapy, using a flat-top hand-piece at higher-fluence irradiation on BMSCs, is able to switch photon signals into the stimulation of biochemical/differentiating pathways involving key activators that regulate de novo actin polymerization. Namely, for the first time, we unearthed the role of the flat-top hand-piece at higher-fluence irradiation on cytoskeletal characteristics of BMSCs. These novel findings meet the needs of novel therapeutically protocols provided by laser treatment and the manipulation of BMSCs as anti-inflammatory, osteo-inductive platforms.

Electromagnetic Dosimetry for Isolated Mitochondria Exposed to Near-Infrared Continuous-Wave Illumination in Photobiomodulation Experiments.

This paper presents results on the electromagnetic field computed inside isolated mitochondria when they are exposed to near-infrared illuminations with reference to photobiomodulation experiments. The accurate calculation of the electromagnetic dose is considered to be important for a better understanding of the mechanism of interaction of light with these organelles and to improve the reliability and repeatability of the experiments. To get such results, we introduce several models. Even though they refer to a well-defined experimental setup, different models are necessary to take into account the possible different dispositions of the mitochondria, and of the differences in their dimensions and in their constitutive parameters. Different wavelengths and polarizations are considered as well. The effects of all parameters on the electromagnetic field inside mitochondria are discussed. © 2021 Bioelectromagnetics Society.

Improving Consistency of Photobiomodulation Therapy: A Novel Flat-Top Beam Hand-Piece versus Standard Gaussian Probes on Mitochondrial Activity.

The tremendous therapeutic potential of photobiomodulation therapy in different branches of medicine has been described in the literature. One of the molecular mechanisms for this treatment implicates the mitochondrial enzyme, cytochrome C oxidase. However, the efficacy and consistency of clinical outcomes with photobiomodulation treatments has been fiercely debated. This work was motivated by this need to improve photobiomodulation devices and delivery approaches. We designed a novel hand-piece with a flat-top beam profile of irradiation. We compared the beam profile versus a standard hand-piece and a fibre probe. We utilized isolated mitochondria and performed treatments at various spots within the beam, namely, the centre, left and right edge. We examined mitochondrial activity by assessing ATP synthesis with the luciferin/luciferase chemiluminescent method as a primary endpoint, while mitochondrial damage was assessed as the secondary endpoint. We observed a uniform distribution of the power density with the flat-top prototype compared to a wide Gaussian beam profile with the standard fibre and standard hand-piece. We noted increased production of ATP in the centre of all three beams with respect to the non-treated controls (p < 0.05). Both the fibre and standard hand-piece demonstrated less increase in ATP synthesis at the edges than the centre (p < 0.05). In contrast, ATP synthesis was increased homogenously in the flat-top handpiece, both in the centre and the edges of the beam. Fibre, standard hand-piece and the flat-top hand-piece prototype have discrete beam distribution characteristics. This significantly affected the mitochondrial activity with respect to their position within the treated areas. Flat-top hand-piece enhances the uniformity of photobiomodulation treatments and can improve the rigour and reproducibility of PBM clinical outcomes.

Photobiomodulation by Near-Infrared 980-nm Wavelengths Regulates Pre-Osteoblast Proliferation and Viability through the PI3K/Akt/Bcl-2 Pathway.

BACKGROUND: bone tissue regeneration remains a current challenge. A growing body of evidence shows that mitochondrial dysfunction impairs osteogenesis and that this organelle may be the target for new therapeutic options. Current literature illustrates that red and near-infrared light can affect the key cellular pathways of all life forms through interactions with photoacceptors within the cells' mitochondria. The current study aims to provide an understanding of the mechanisms by which photobiomodulation (PBM) by 900-nm wavelengths can induce in vitro molecular changes in pre-osteoblasts. METHODS: The PubMed, Scopus, Cochrane, and Scholar databases were used. The manuscripts included in the narrative review were selected according to inclusion and exclusion criteria. The new experimental set-up was based on irradiation with a 980-nm laser and a hand-piece with a standard Gaussian and flat-top beam profile. MC3T3-E1 pre-osteoblasts were irradiated at 0.75, 0.45, and 0.20 W in continuous-wave emission mode for 60 s (spot-size 1 cm2) and allowed to generate a power density of 0.75, 0.45, and 0.20 W/cm2 and a fluence of 45, 27, and 12 J/cm2, respectively. The frequency of irradiation was once, three times (alternate days), or five times (every day) per week for two consecutive weeks. Differentiation, proliferation, and cell viability and their markers were investigated by immunoblotting, immunolabelling, fluorescein-FragELTM-DNA, Hoechst staining, and metabolic activity assays. RESULTS AND CONCLUSIONS: The 980-nm wavelength can photobiomodulate the pre-osteoblasts, regulating their metabolic schedule. The cellular signal activated by 45 J/cm2, 0.75 W and 0.75 W/cm2 consist of the PI3K/Akt/Bcl-2 pathway; differentiation markers were not affected, nor do other parameters seem to stimulate the cells. Our previous and present data consistently support the window effect of 980 nm, which has also been described in extracted mitochondria, through activation of signalling PI3K/Akt/Bcl-2 and cyclin family, while the Wnt and Smads 2/3-ß-catenin pathway was induced by 55 J/cm2, 0.9 W and 0.9 W/cm2.

Mitochondrial Bioenergetic, Photobiomodulation and Trigeminal Branches Nerve Damage, What's the Connection? A Review.

BACKGROUND: Injury of the trigeminal nerve in oral and maxillofacial surgery can occur. Schwann cell mitochondria are regulators in the development, maintenance and regeneration of peripheral nerve axons. Evidence shows that after the nerve injury, mitochondrial bioenergetic dysfunction occurs and is associated with pain, neuropathy and nerve regeneration deficit. A challenge for research is to individuate new therapies able to normalise mitochondrial and energetic metabolism to aid nerve recovery after damage. Photobiomodulation therapy can be an interesting candidate, because it is a technique involving cell manipulation through the photonic energy of a non-ionising light source (visible and NIR light), which produces a nonthermal therapeutic effect on the stressed tissue. METHODS: The review was based on the following questions: (1) Can photo-biomodulation by red and NIR light affect mitochondrial bioenergetics? (2) Can photobiomodulation support damage to the trigeminal nerve branches? (preclinical and clinical studies), and, if yes, (3) What is the best photobiomodulatory therapy for the recovery of the trigeminal nerve branches? The papers were searched using the PubMed, Scopus and Cochrane databases. This review followed the ARRIVE-2.0, PRISMA and Cochrane RoB-2 guidelines. RESULTS AND CONCLUSIONS: The reliability of photobiomodulatory event strongly bases on biological and physical-chemical evidence. Its principal player is the mitochondrion, whether its cytochromes are directly involved as a photoacceptor or indirectly through a vibrational and energetic variation of bound water: water as the photoacceptor. The 808-nm and 100 J/cm2 (0.07 W; 2.5 W/cm2; pulsed 50 Hz; 27 J per point; 80 s) on rats and 800-nm and 0.2 W/cm2 (0.2 W; 12 J/cm2; 12 J per point; 60 s, CW) on humans resulted as trustworthy therapies, which could be supported by extensive studies.

Xerostomia and hyposalivation in patients with obstructive sleep apnoea.

OBJECTIVE: (a) To report the xerostomia prevalence and severity in patients with obstructive sleep apnoea (OSA). (b) To assess the saliva pH in patients with OSA. DESIGN: Simultaneous cohort observational clinical study. SETTING: In Sleep Medicine Centre at Lomonosov Moscow State University from March to June 2019. PARTICIPANTS: The study was conducted on 30 patients with OSA aged from 35 to 65 years. MAIN OUTCOMES MEASURES: The diagnosis of sleep apnoea was made after standard polysomnography using the Domino programme. The severity of OSA was indicated using the Apnoea-Hypopnea Index. Xerostomia was evaluated using Fox's test. Hyposalivation was evaluated by measurement of salivary flow rate. Determination of the saliva pH was carried out with a pH metre. Statistical analysis was performed by one-way ANOVA and Tukey-Kramer multi-comparison test. RESULTS: Twenty-two out of 30 (73.3%) patients were diagnosed with "dry mouth". Hyposalivation was observed in 6 out of 30 (20%). Dry mouth on awakening was observed in 60.0%, 72.7% and 88.9% of patients with mild, moderate and severe OSA, respectively. The average salivary flow rate was 0.28 mL/min, 0.24 mL/min and 0.14 mL/min, respectively. The average pH value in patients with mild, moderate and severe apnoea was 6.40 ± 0.017, 6.15 ± 0.27 and 5.87 ± 0.24, respectively. CONCLUSIONS: In patient with mild and moderate OSA, the saliva amount and rate are similar (P > .05). With the increase of OSA severity, both these parameters change (P < .001). The acidity of the saliva was correlated with the level of OSA, and it statistically increased with the increment of the OSA severity (P < .05-P < .001).

pH Evaluation over a Period of 6 months of Two-bottle Water-based Self-etching Primers: An In Vitro Study.

AIM AND OBJECTIVE: The objective of this study was to monitor the pH stability over a period of 6 months of two-bottle self-etching (SE) primers. MATERIALS AND METHODS: Four commercially available two-bottle SE primer solutions, Adhese SE (Ivoclar Vivadent; Schaan, Liechtenstein), Clearfil SE (Kuraray; Tokyo, Japan), Contax Primer (DMG; Hamburg, Germany), and Enabond SE (Micerium; Avegno (Ge), Italy), containing water as the main solvent were selected. The pH values during a 6-month storage period at intermittent temperature were daily measured by means of a microprocessor-based pH/temperature meter and hence recorded, tabulated, and analyzed. RESULTS: The mean values of overall pH measurements and standard deviation for Adhese SE, Clearfil SE, Contax Primer, and Enabond SE are, respectively, 1.70 (±0.01), 1.72 (±0.01), 1.20 (±0.01), 1.80 (±0.01). One-way ANOVA did not detect any significant change of the mean pH values of all measurements over time. CONCLUSION: The conventional 6-months storage did not affect the pH values of the water-containing primers of two-bottle SE adhesives. CLINICAL SIGNIFICANCE: This study provides evidence that conventional storage under adequate conditions did not affect the pH values of the water-containing primers of two-bottle SE adhesives with different monomer formulations. Clinicians may rely on the known pH value of the selected SE adhesive during shelf-life.

Free Gingival-Bone Graft in the Anterior Maxilla: A Clinical Case Report.

AIM: To present the healing, development, and long-term clinical results after a combined gingival-bone graft as an alternative treatment for the management of critical extraction sites in the esthetic zone. BACKGROUND: To enhance the knowledge of in vivo soft and hard tissue remodeling, in this case report, we observed the healing, development, and long-term clinical results after a case of a combined gingival-bone graft as an alternative treatment for the management of critical extraction sites. CASE DESCRIPTION: Autogenous grafts of gingival and bone tissue were placed in a 56-year-old female patient, where a hopeless upper left central incisor with an evident loss of both the buccal and the palatal bony plates and with endodontic problems was due for extraction. In order to obtain enough autogenous tissue for filling the defect, a cylindrical free gingival and bone graft was retrieved from the retromolar area with a trephine drill, to obtain hard and soft tissues for grafting the postextraction defect. After 6 months, following soft tissue maturation and once esthetic and natural gingival contours were achieved, the surgical site was prosthetically restored with a porcelain fused to a metal bridge and scheduled for regular follow-up. CONCLUSION: No complications were observed either from the donor site or from the recipient site. The post-treatment result was esthetically pleasing, based upon successful architectural stability of both hard and soft tissues. Although more studies are needed to confirm the beneficial use of this approach, the procedure can be considered a viable option in the management of soft and hard tissue remodeling in esthetically compromised cases. CLINICAL SIGNIFICANCE: The gingival-bone graft may be considered as an alternative treatment for the management of critical extraction sites in the esthetic area. How to cite this article: Signore A, Stepanov M, Angelis ND, et al. Free Gingival-Bone Graft in the Anterior Maxilla: A Clinical Case Report. J Contemp Dent Pract 2021;22(5):568-571.

Apical Leakage Evaluation of Two Different Coated Carrier Systems for Root Canal Obturation Using a Dye Penetration Evaluation Method.

AIM: The carrier-based obturation is a reliable technique for sealing the endodontic space. The GuttaCore with a pink internal core of cross-linked gutta-percha, named GuttaCore Pink, has been recently introduced into the market. The aim of this in vitro study was to compare the quality of the apical seal of two-carrier-based system, Soft Core and the GuttaCore Pink, through the measurement of apical dye leakage. MATERIALS AND METHODS: Eighty-six extracted human teeth with single canals were used. Samples were shaped using ProTaper Universal rotary files up to a #30 apical size and randomly divided into four groups. Group SC (n = 40) was obturated with #30 Soft Core Obturators; Group GCP (n = 40) was obturated with #30 GuttaCore Pink obturators; Group CT+ (n = 3) and CT- (n = 3) left nonobturated used as positive and negative controls, respectively. The samples underwent a process of passive/active dye penetration and after a clearing procedure. The extent of the dye was measured under stereomicroscope. RESULTS: The Mann-Whitney U test showed a statistically significant difference (p <0.05) between Soft Core and GuttaCore Pink in terms of apical dye leakage, both considering the mean and the maximum infiltration value with a greater infiltration rate for Soft Core. CONCLUSION: In vitro GuttaCore Pink showed less apical dye leakage than Soft Core. CLINICAL SIGNIFICANCE: The apical leakage of carrier-based obturation materials, observed in both GuttaCore Pink and Soft Core, may be considered material-dependent.

Loss of p62 impairs bone turnover and inhibits PTH-induced osteogenesis.

The p62 (also named sequestosome1/SQSTM1) is multidomain and multifunctional protein associated with several physiological and pathological conditions. A number of studies evidenced an involvement of p62 on the disruptive bone scenarios due to its participation in the inflammatory/osteoclastogenic pathways. However, so far, information regarding the function of p62 in the fine-tuned processes underpinning the bone physiology are not well-defined and are sometime discordant. We, previously, demonstrated that the intramuscular administration of a plasmid coding for p62 was able to contrast bone loss in a mouse model of osteopenia. Here, in vitro findings showed that the p62 overexpression in murine osteoblasts precursors enhanced their maturation while the p62 depletion by a specific siRNA, decreased osteoblasts differentiation. Consistently, the activity of osteoblasts from p62-/- mice was reduced compared with wild-type. Also, morphometric analyses of bone from p62 knockout mice revealed a pathological phenotype characterized by a lower turnover that could be explained by the poor Runx2 protein synthesis in absence of p62. Furthermore, we demonstrated that the parathyroid hormone (PTH) regulates p62 expression and that the osteogenic effects of this hormone were totally abrogated in osteoblasts from p62-deficient mice. Therefore, these findings, for the first time, highlight the important role of p62 both for the basal and for PTH-stimulated bone remodeling.

Dose-Dependent Clinical, Radiographic, and Histopathologic Changes of 17ß-Estradiol Levels Within the Temporomandibular Joint: An Experimental Study in Ovariectomized Dogs.

PURPOSE: The aim of this study was to test the hypothesis that the dose of estrogen replacement therapy may have an influence on the clinical, radiographic, and histopathologic changes within the temporomandibular joint (TMJ). MATERIALS AND METHODS: A prospective experimental study was conducted in 12 mature ovariectomized dogs. Dogs were randomly allocated into 1 of 4 groups (OVX-E0, dogs that did not receive any estrogen replacement therapy; OVX-E0.5, dogs that received 0.15 mg/kg of estradiol; OVX-E1, dogs that received 0.3 mg/kg of estradiol; and OVX-E2, dogs that received 0.6 mg/kg of estradiol); dogs were evaluated clinically for 12 weeks; and contact radiographic and histopathologic examinations of the TMJ were performed just after euthanasia. RESULTS: Radiographic examination of the TMJ in the OVX-E0 group showed narrowing of the joint space with marginal osteophyte formation along the mandibular condyle. The OVX-E0.5 group showed mild widening of the joint space with no remarkable changes within the mandibular fossa or condyle. The OVX-E1 group was free of radiographic changes within the TMJ. High doses of estrogen in the OVX-E2 group showed marked flattening of the mandibular condyle and fossa with sclerosis of the subchondral bone. Histopathologic sections in the OVX-E0 group showed thin compact bone with scanty, less organized lacunae. The OVX-E0.5 group showed compact bone of medium thickness with large osteons and disorganized lacunae. The OVX-E1 group showed thick compact bone with reduced intertubercular spaces and organized lacunae. The OVX-E2 group showed thin bone with reduced trabecular and increased intertrabecular thickness. The collagen content did not change significantly among the 4 groups, whereas its quality changed significantly (P < .05). CONCLUSIONS: Estrogen dosage is potentially a key regulator of bone metabolism within the TMJ. Estrogen replacement therapy exhibited an inverted U-shaped beneficial effect. Estrogen depletion as well as high doses of estrogen resulted in clinical, radiographic, and histopathologic changes within the TMJ. Estrogen replacement therapy should be prescribed at the optimum dose when indicated as hormonal replacement therapy.

P62 deficiency shifts mesenchymal/stromal stem cell commitment toward adipogenesis and disrupts bone marrow homeostasis in aged mice.

With advancing age have been observed bone and bone marrow phenotypic alterations due to the impaired bone tissue homeostatic features, involving bone remodeling, and bone marrow niche ontogeny. The complex "inflamm-aging" pathological scenario that culminates with osteopenia and mesenchymal/stromal and hematopoietic stem cell commitment breakdown, is controlled by cellular and molecular intramural components comprising adapter proteins such as the sequestosome 1 (p62/SQSTM1). p62, a "multiway function" protein, has been reported as an effective anti-inflammatory, bone-building factor. In this view, we considered for the first time the involvement of p62 in aging bone and bone marrow of 1 year and 2 years p62-/- mice. Interestingly, p62 deficiency provoked accelerated osteopenia and impaired niche operational activities within the bone marrow. The above findings unearthed the importance of p62 in mesenchymal stem cell maintenance/differentiation schedule in old animals and provide, at least in part, a mechanistic scenario of p62 action.

First identification of a fatal fungal infection of the marine sponge Chondrosia reniformis by Aspergillus tubingensis.

Sponges are considered promising sources of biomolecules for both pharmaceutical and cosmetic interests as well as for the production of biomaterials suitable for tissue engineering and regenerative medicine. Accordingly, the ability to grow sponges in captivity and in healthy conditions to increase their biomass is a required goal for the development of sponge aquaculture systems. To date, little information is available about the pathogenicity of fungi associated with sponges. In our study, we identified an infection in freshly collected specimens of Chondrosia reniformis (Porifera, Demospongiae) and determined that the fungus Aspergillus tubingensis was the pathogen responsible. This is the first description of a natural infection of C. reniformis by A. tubingensis. Despite raising an inflammatory response by means of an increase in tumour necrosis factor (TNF) mRNA, the infected C. reniformis specimens were not able to control the fungal infection, leading to rotting in 15 d. Characterization of this infection shows that a widely distributed fungus can represent a potential hazard to sponge aquaculture industries and how, especially in stressed or compromised marine environments, this fungus could represent a fatal opportunistic pathogen.

Correction to: Outpatient erbium:YAG (2940 nm) laser treatment for snoring: a prospective study on 40 patients.

In the originally published article, the name of the first author was incorrectly labeled. Given name is Isabelle and family name is Fini Storchi.

Photobiomodulation with 808-nm diode laser light promotes wound healing of human endothelial cells through increased reactive oxygen species production stimulating mitochondrial oxidative phosphorylation.

Photobiomodulation of cells using near-infrared (NIR) monochromatic light can affect cell functions such as proliferation, viability, and metabolism in a range of cell types. Evidence for the effects of near-infrared light on endothelial cells has been reported, but the studies were mainly performed using VIS light emitted by low-energy lasers, because NIR wavelengths seemed negatively stimulate these cells. Cell viability, free radical-induced oxidative stress, NF-κB activation, nitric oxide release, mitochondrial respiration, and wound healing repair were assessed in human endothelial cells (HECV) irradiated with 808-nm diode laser light (laser setup = 1 W/cm2, 60 s, 60 J/cm2, CW vs measured energy parameter = 0.95 W/cm2, 60 s, 57 J/cm2, mode CW) emitted by an handpiece with flat-top profile. No difference in viability was detected between controls and HECV cells irradiated with 808-nm diode laser light for 60 s. Irradiated cells demonstrated higher proliferation rate and increased migration ability associated to moderate increase in ROS production without a significant increase in oxidative stress and oxidative stress-activated processes. Near-infrared light stimulated mitochondrial oxygen consumption and ATP synthesis in HECV cells. Short near-infrared irradiation did not affect viability of HECV cells, rather led to a stimulation of wound healing rate, likely sustained by ROS-mediated stimulation of mitochondrial activity. Our results demonstrating that near-infrared led to a shift from anaerobic to aerobic metabolism provide new insight into the possible molecular mechanisms by which photobiomodulation with 808-nm diode laser light protects against inflammation-induced endothelial dysfunction, seemingly promising to enhance their therapeutic properties.

Outpatient erbium:YAG (2940 nm) laser treatment for snoring: a prospective study on 40 patients.

Snoring is a sleep phenomenon due to the partial upper airway obstruction during sleep which causes vibration of the tissues of the rhino-oro-hypopharynx and less frequently the larynx. This study evaluated the use and effectiveness of the erbium:YAG 2940-nm laser as an adjunctive in providing treatment for patients suffering from chronic snoring-related sleep disorders. A prospective study of 40 consecutive patients with snoring and sleep disorders was performed, assessing data before and after three Er:YAG laser treatment sessions. During laser treatment, the pain was almost absent. There were no side effects, except a very mild sore throat in 1 out of 40 patients. The patient's evaluation of satisfaction of the results obtained after the treatments showed that 85% of cases were very satisfied, 5 patients (12.5%) reported being fairly satisfied with the treatment and only 1 subject (2.5%) was not satisfied. Mallampati, Friedman Tongue Position, and degree of O (oropharynx) at nose oropharynx hypopharynx and larynx classification were significantly decreased after the laser sessions. The decrease of Epworth Sleepiness Scale and Visual Analogue Scale for loudness of snoring, waking up during sleep because of snoring, dry mouth on waking, and choking was all statistically significant. The incidence of dreaming during the night also raised significantly; 30/40 (75%) of cases perceived less tightness in their throat and better breathing after treatment. These results were stable at 20 months follow-up (14-24 q) in 72% of cases. Nonsurgical and non-invasive Er:YAG laser treatment demonstrated to be a valid procedure in reducing the loudness of snoring.

808-nm laser therapy with a flat-top handpiece photobiomodulates mitochondria activities of Paramecium primaurelia (Protozoa).

Photobiomodulation is proposed as a non-linear process, and only low-level laser therapy (LLLT) is assumed to stimulate exposed cells, whereas high powered laser and fluences can cause negative effects, exhausting the cell's energy reserve as a consequence of excessive photon-based stimulation. In our work, we investigated and compared the effects of 808-nm diode laser (CW) with a new flat-top handpiece. To this purpose, we tested the photobiomodulation effects of 1 and 3 J/cm(2) fluence, both generated by 100 mW or 1 W of laser power and of 64 J/cm(2) of fluence generated by 100 mW, 1 W, 1.5 W or 2 W, as expressed through oxygen consumption and ATP synthesis of Paramecium. Data collected indicates the incremental consumption of oxygen through irradiation with 3 J/cm(2)-100 mW or 64 J/cm(2)-1 W correlates with an increase in Paramecium ATP synthesis. The Paramecium respiration was inhibited by fluences 64 J/cm(2)-100 mW or 64 J/cm(2)-2 W and was followed by a decrease in the endogenous ATP concentration. The 1 J/cm(2)-100 mW or 1 W and 3 J/cm(2)-1 W did not affect mitochondrial activity. The results show that the fluence of 64 J/cm(2)-1 W more than the 3 J/cm(2)-100 mW causes greater efficiency in Paramecium mitochondria respiratory chain activity. Our results suggest that thanks to flat-top handpiece we used, high fluences by high-powered laser have to be reconsidered as an effective and non-invasive therapy. Possible associated benefits of deeper tissue penetration would increase treatment effectiveness and reduced irradiation time.