Influence Of Low-level Laser Therapy Research Articles

The brain functional connectivity alterations in traumatic patients with olfactory disorder after low-level laser therapy demonstrated by fMRI.

Low-level laser therapy (LLLT) has been clinically accepted to accelerate the nerve regeneration process after a nerve injury or transection. We aimed to investigate the neuronal basis and the influence of LLLT on brain functional networks in traumatic patients with olfactory dysfunction. Twenty-four Patients with traumatic anosmia/hyposmia were exposed to pleasant olfactory stimuli during a block-designed fMRI session. After a 10-week period, patients as control group and patients who had completed the sessions of LLLT were invited for follow-up testing using the same fMRI protocol. Two-sample t-tests were conducted to explore group differences in activation responding to odorants (p-FDR-corrected <0.05). Differences of functional connectivity were compared between the two groups and the topological features of the olfactory network were calculated. Correlation analysis was performed between graph parameters and TDI score. Compared to controls, laser-treated patients showed increased activation in the cingulate, rectus gyrus, and some parts of the frontal gyrus. Shorter pathlength (p = 0.047) and increased local efficiency (p = 0.043) within the olfactory network, as well as decreased inter-network connectivity within the whole brain were observed in patients after laser surgery. Moreover, higher clustering and local efficiency were related to higher TDI score, as manifested in increased sensitivity to identify odors. The results support that low-level laser induces neural reorganization process and make new connections in the olfactory structures. Furthermore, the connectivity parameters may serve as potential biomarkers for traumatic anosmia or hyposmia by revealing the underlying neural mechanisms of LLLT.

Impact of Low-Level Laser Therapy on Orthodontic Tooth Movement and Various Cytokines in Gingival Crevicular Fluid: A Split-Mouth Randomized Study.

A few investigations have detailed the influence of low-level laser therapy (LLLT) on orthodontic tooth movement (OTM), with varying results. The objectives of this study were twofold: to assess the impact of LLLT on OTM and various cytokine levels in gingival crevicular fluid and to contrast the pain levels experienced by patients receiving orthodontic treatment with and without LLLT. This split-mouth randomized controlled prospective study comprised 40 patients with an average age of 19.7±2.4 years with Angle Class I malocclusion combined with bimaxillary protrusion who were advised for extraction of the maxillary first premolar and bilateral canine distalization. The control-side canine was distalized solely by the coil spring. On the test arm, a low-level gallium-aluminum-arsenide semiconductor diode laser operating at 980 nm and 100 mW with a continuous-wave energy of 8 J/cm2 was used. The canine distalization on either side was measured with a digital caliper following the first premolar extraction (TO), one month after treatment (TOTM1), two months later (TOTM2), and three months later (TOTM3). The gingival index and the level of various cytokines were determined by an enzyme-linked immunosorbent assay at the beginning of the study, on the third and seventh days, and at four, eight, and 12 weeks following the canine distalization. The intra-group and inter-group comparisons were carried out using one-way analysis of variance (ANOVA) and t-tests, respectively, at a 5% significance level. The results show a highly statistically significant difference in the extent of canine distalization in the test group (TOTM1=2.92±0.44; TOTM2=1.04±0.1; TOTM3​=0.62±0.21 mm) in contrast to the control group (TOTM1=3.23±0.8; TOTM2=2.65±0.2; TOTM3​​​​=2.11±0.24 mm) (p<0.01). After three months of canine distalization, the laser and control group had 34 and 27 patients with mild gingivitis, respectively. Interleukin-1β and interleukin-6 concentrations surged with values of 0.74±0.13 and 0.049±0.001 pg/g at seven days following treatment in the laser group, respectively. The difference in tumor necrosis factor concentration between the groups was shown to be highly statistically significant in all treatment phases (p<0.001). The differences in the epidermal growth factor and microglobulin levels were found to be statistically significant within both groups from T0 to T5.The average visual analog scale (VAS) scores at several subsequent evaluations of the laser and control groups were found to be highly statistically significant. The findings imply that when the periodontal microenvironment is stimulated by orthodontic force, several paramount cytokines are released, triggering an ordered sequence of biological processes that appear to expedite OTM with reduced associated pain.

The Influence of Low-Level Laser Therapy on CBCT Radiographic and Biochemical Profiles of Type II Controlled Diabetic Patients After Dental Implant Insertion: A Randomized Case-Control Study.

Background Low-level laser treatment (LLLT) was thought to increase bone quality during osseointegration when combined with dental implants. However, there is no sufficient information on its impact on dental implants in diabetics. Osteoprotegerin (OPG) has been described as a marker for bone turnover to determine implant prognosis. The current research aims to evaluate the effect of low-level laser therapy (LLLT) on bone density (BD) and osteoprotegerin levels in peri-implant crevicular fluid (PICF) in type II diabetic patients. Methods This study comprised 40 individuals with type II diabetes mellitus (T2DM). Implants were randomly placed in 20 non-lasered T2DM patients (control) and 20 lasered T2DM patients (LLLT group). At the follow-up stages, BD and OPG levels in the PICF were evaluated in both groups. Results Significant variations were shown among control and LLLT groups concerning OPG level and BD (p≤0.001). OPG was significantly decreasing with follow-up points (p≤0.001). There was a significant decrease in OPG with time in both groups with a higher decrease in the control group. Conclusion LLLT is promising in controlled T2DM patients due to its outstanding influence on BD and estimated crevicular levels of OPG. Regarding its clinical significance, LLLT significantly improved bone quality during osseointegration on dental implants in T2DM.LLLT is considered potentially important for T2DM patients during implant placement. Trial registration The study was registered on ClinicalTrial.govunder registration number NCT05279911 (registration date: March 15, 2022) (https://clinicaltrials.gov/ct2/show/NCT05279911).

ВЛИЯНИЕ НИЗКОИНТЕНСИВНОГО ЛАЗЕРНОГО ИЗЛУЧЕНИЯ НА ИММУНОЛОГИЧЕСКИЕ ПОКАЗАТЕЛИ У ПАЦИЕНТОВ С ФЛЕГМОНАМИ ЧЕЛЮСТНО-ЛИЦЕВОЙ ОБЛАСТИ И ШЕИ

Background. The problem of treatment of phlegmon of the maxillofacial region and neck remains one of the most urgent problems of maxillofacial surgery. Aim. To determine the degree of influence of local Low Level Laser Therapy (LLLT) on the quantitative and functional characteristics of immunocytes and humoral factors in peripheral blood and lavage fluid in phlegmon of the maxillofacial region and neck. Material and methods. We have examined and treated 60 patients with phlegmon of the maxillofacial region and neck. Of these, 30 people made up group 1 – traditional treatment and 30 people were included into group 2 (traditional treatment supplemented with local LLLT). Also, 12 practically healthy individuals were examined to determine the regional norm of the selected indicators (control group). The total number of leukocytes and their subpopulations were determined in the blood and lavage fluid, immunophenotyping of lymphocytes was performed using monoclonal antibodies (CD3+, CD4+, CD8+, CD16+, CD19+, CD25+, CD95+), determination of the phagocytic index (PhI) and phagocytic number (PhN), the study of hemolytic complement activity (CH50), the presence of circulating immune complexes (CIC) and the level of immunoglobulins (Ig) of classes M, A, G. Results. Weekly local exposure of LLLT contributed to a decrease in leukocytes and neutrophils in the blood with an increase in their functional activity (PhN), an increase in the number of lymphocytes, levels of IgM, IgG, while reducing CH50 in blood serum. In the lavage fluid under the influence of LLLT, a decrease in leukocytes, neutrophils, activation of phagocytosis, an increase in lymphocytes due to the number of CD3+ and CD4+ T-lymphocytes, a decrease in CD8+ of cytostatic T-lymphocytes, CD25+ activated T- and B-lymphocytes, CD95+T- and B-lymphocytes, decrease in CH50, IgM level and increase in IgG were revealed. Conclusion. Comprehensive treatment of patients with phlegmon of the maxillofacial region supplemented with LLLT has a modulating effect on cellular and humoral immunity factors by enhancing the local immune response.

Serum Level of Il-2 in Patients with Type 2 Diabetes Mellitus and Periodontopathy

The purpose of this study was to investigate the influence of low-level laser therapy (LLLT) in patients with type 2 diabetes mellitus (T2DM) and chronic periodontopathy (ChP) on serum levels of IL-2. Methods and Results: A total of 80 patients aged 35-60 years were followed; all of them had T2DM diagnosed (HbA1C≤7.5%) with ChP, where clinical attachment loss (CAL) was ≥4mm on at least 50% of affected teeth. All participants are divided into two groups. Group A included 40 patients who underwent conservative (non-surgical) periodontal treatment supplemented with LLLT. Group B included 40 patients who underwent only conservative therapy. Patients used oral antidiabetic medications to control glycemia: Metformin (Alkaloid, Skopje S. Macedonia) 500 mg two times a day. LLLT (Laser HF® comfort, Hager. Werken, Duisburg, Germany) was applied (660 nm, 10 mW, 8 min/day) with contact to the gingiva for five consecutive days. Serum IL-2 was determined by ELISA in 3 time intervals: at the first examination, 6 weeks, and 3 months after treatment in both groups. In Group A and Group B, at the first examination, 6 weeks after therapy, and 3 months after treatment, the serum IL-2 was 17.20±0.54 pg/ml and 17.22±0.66 pg/ml, 17.12±0.63 pg/ml and 17.17±0.63 pg/ml, and 17.03±0.64 pg/ml and 16.98±0.65 pg/ml, respectively. In Group A, there was a significant difference between the serum IL-2 values in specified time points (first examination, 6 weeks, and 3 months after the therapy) (Friedman’s ANOVA: χ² (n=40, df=2) = 17.22 and P=0.0002). In Group B, between the serum IL-2 levels, there also was a significant difference in specified time points (Friedman’s ANOVA: χ² (n=40, df=2) = 42.33 and P=0.0000). The intergroup analysis, according to the temporal dynamics of the measurements, showed an evident difference between the two groups, but the serum IL-2 values in the two groups treated with and without LLLT were close, and no statistical significance was recorded between them. Conclusion: No significant differences were recorded in the serum IL-2 levels in T2DM patients with ChP non-surgically treated with and without the application of LLLT.

Changes in Cell Biology under the Influence of Low-Level Laser Therapy

Low-level laser therapy (LLLT) has become an important part of the therapeutic process in various diseases. However, despite the broad use of LLLT in everyday clinical practice, the full impact of LLLT on cell life processes has not been fully understood. This paper presents the current state of knowledge concerning the mechanisms of action of LLLT on cells. A better understanding of the molecular processes occurring within the cell after laser irradiation may result in introducing numerous novel clinical applications of LLLT and potentially increases the safety profile of this therapy.

Influence of low-level laser therapy on implant stability in implants placed in healed sites: a randomized controlled trial

BackgroundThe present study aims to assess the influence of low-level laser therapy (LLLT) on stability in implants placed in healed sites.Material and methodsThe present study followed the SPIRIT statement and is reported according to CONSORT. Patients were randomly allocated to LLLT or control groups. LLLT consisted in the application of 808-nm GaAlA laser applied before the preparation of the implant bed and after suturing (80 seconds; 11J/cm2). Implant stability quotient (ISQ) and the distance between the implant platform to the alveolar bone crest (millimeters) were assessed at implant placement (T0) and the abutment selection phase (4–6 months, Ta).ResultsA total of 64 implants were placed in 33 patients. The insertion torque ranged from 10 to 70 N.cm (mean 43.23; SD ±16.82). The T0 ISQ ranged from 18 to 95.5 (mean 61.7; SD ±18.23) and the crestal bone radiographic distance was 2.03 mm (SD±1.27). At Ta, the ISQ ranged from 39 to 90 (mean 64.2; SD±9.84), and the mean crestal bone radiographic loss was 1.70mm (SD±1.65). However, no differences were observed when LLLT and control groups were compared with ISQ difference (Ta–T0; p=0.598) or radiographical peri-implant alterations (p=0.531).ConclusionLLLT did not influence the implant stability in implants placed in healed sites compared to a control group.Trial registrationReBEC, RBR-35TNJ7. Registered May 23, 2018

Male autoimmune infertility: analysis of results and prediction of efficacy of low-level laser therapy in infrared spectrum

INTRODUCTION: Autoimmune infertility is diagnosed in 515% of men. Currently applied methods of medical therapy of autoimmune male infertility are not very effective, which requires the development of new ones and creation of predictive algorithms for their efficacy.&#x0D; The aim of our study was to evaluate the influence of low-level laser therapy (LLLT) in infrared spectrum on MAR-test rate and sperm fertile properties in men with autoimmune infertility, develop ways to predict the efficacy of this therapy.&#x0D; PATIENTS AND METHODS: 47 men with autoimmune infertility were examined. 31 of them (1st group) underwent course of LLLT in infrared spectrum (10 procedures), and 16 patients (2nd group, comparison) had placebo-laser therapy sessions (10 procedures). MAR-test value, main semen parameters and sperm DNA fragmentation were assessed before and after the treatment. For creation of LLLT efficacy algorithm we used discriminate analysis.&#x0D; RESULTS: In patients of the 1st group we indicated statistically significant decrease of MAR-test by an average of 19% immediately after the course of procedures, and by 33% within two months after the end of the treatment, at its initial level 60% or lower. LLLT contributed to improvement of the semen fertile properties, pregnancy developed in the natural reproductive cycle in 19% of couples. We developed math model for prediction the efficacy of LLLT in infrared spectrum of autoimmune male infertility.&#x0D; CONCLUSION: LLLT in infrared spectrum of male autoimmune infertility leads to MAR-test value decrease at its initial level less than 60%; improves sperm fertile properties. It is appropriate to use before LLLT predictive algorithm of its efficacy developed by us.

Effects of diode low-level laser therapy on healing of tooth extraction sockets: a histopathological study in diabetic rats

Diabetes mellitus is mostly interrelated to deficiency in wound healing. Low-level laser therapy has been shown to exert reliable effects on the acceleration of wound healing process. This study aimed to determine the potential influence of low-level laser therapy (LLLT) on the healing of extraction sockets in diabetic rats. A total of 24 healthy male Wistar rats were selected for this study. After diabetes induction, the maxillary first molars of all rats were extracted bilaterally. Then, the animals were subjected either to Ga-Al-As laser at 808 nm or to Al-Ga-In-P laser at 660 nm at the right extracted socket every day for the next 14 days. The left sockets served as controls. Rats were sacrificed on the 3rd, 5th, 7th, and 14th days after tooth extraction. The samples were examined by a pathologist. LLLT at 808 nm was able to significantly repress inflammation, improve osteoid formation, and promote vascularization in comparison to the non-treated sockets. LLLT at 660 nm significantly suppressed inflammation and developed vascularization in comparison to the non-treated sockets, but failed to improve osteoid formation in the treated sockets. This study suggests that LLLT could be considered asa reliable treatment for wound healing in diabetic experimental rats.

No Clear Evidence for the Effect of Low-Level Laser Treatment on Orthodontically Induced Inflammatory Root Resorption: More Human Clinical Studies Are Needed

Influence of low-level laser therapy on orthodontically induced inflammatory root resorption. A systematic review. Michelogiannakis D, l-Shammery D, Akram Z, Rossouw PE, Javed F, Romanos GE. Arch Oral Biol 2019;100:1-13. The authors reported that this article did not receive any specific grants from funding agencies in the public, commercial, or nonprofit sectors. Systematic review.

Influence of low-level laser therapy on implant stability in implants placed in fresh extraction sockets: A randomized clinical trial.

Low-level laser therapy (LLLT) has been suggested to improve primary stability at the early stages of osseointegration in animal models. However, there is still scarce evidence about its influence on implant stability in humans. To assess the influence of LLLT on implant stability in implants placed in fresh extraction sockets. A randomized controlled trial was designed according to the SPIRIT guidelines and is reported following the CONSORT. Patients were randomly allocated according to control or LLLT groups. LLLT consisted in the application of GaAlAs laser (808 nm, avg. power density: 50 mW, circular spot diameter and area: 0.71 cm/0.4cm2 ) applied in six points in contact mode with peri-implant soft tissue (1.23 minutes in each point of application; dose per point 11 J) before bone perforation and after suturing. The total dose resulted in 66 J per application moment. This LLLT protocol was applied only in the dental implant placement session. Implant stability was by ISQ at implant placement (T0 ) and the abutment selection (Ta ). Digital radiographs for T0 and Ta were used to assess the distance between the implant platform and alveolar bone crest, in millimeters. T-test and Shapiro-Wilk test were used to analyze data between groups using the implant as a unit of analysis. Fifty implants were placed in 44 patients. The insertion torque ranged from 15 to 60 N.cm (mean 35.64 ± 13.34). Two implants of the LLLT and one of the control groups were lost to follow-up and one implant of the control group failed to osseointegrate (4.3%). ISQ at T0 ranged from 17 to 79 (mean 59.33 ± 13.05) and from 40 to 89 (mean 66.46 SD ± 11.56) at Ta . No differences were observed when comparing the groups with ISQ difference (P = .433) or radiographical peri-implant alterations (P = .261). LLLT did not influence implant stability in implants placed in fresh extraction sockets when assessed at healing abutment installation.

Low Intensity Laser Influence on Orthodontic Movement: A Randomized Clinical and Radiographic Trial

Introduction: Finding a method to decrease orthodontic treatment time has been a concern for several authors. This study evaluated, clinically and radiographically, the influence of low-level laser therapy on the rate of orthodontic movement and dental tissue integrity. Methods: The sample included 11 individuals with class I malocclusion, requiring extraction of 4 first premolars. Gallium aluminum arsenide diode laser with a wavelength of 780 nm was used once a month during retraction mechanics, to irradiate the maxillary and mandibular canines on one side and compare them with the nonirradiated contralateral side, after spring activation, until canine retraction was completed. This was followed by movement measurement. Periapical radiographs were used to check for possible modifications in the supporting tissues and root surface of the displaced canines. Results: No differences in the rate of tooth movement were found between the irradiated and nonirradiated side on both dental arches. There was no resorption of the root and/or alveolar bone crest, maintaining the integrity of these tissues. Conclusions: Low-level laser therapy did not promote an increment on the rate of tooth movement and did not cause greater root and alveolar bone crest resorption than on the nonirradiated side with the used protocol.

Influence of low-level laser therapy on inflammation, collagen fiber maturation, and tertiary dentin deposition in the pulp of bleached teeth.

We evaluated the effects of low-level laser therapy (LLLT) using an infrared laser (IRL) and a red laser (RL) on the pulp of molar teeth in rats after dental bleaching to assess inflammation, collagen fiber maturation, and tertiary dentin formation. Eighty Wistar rats (Rattus norvegicus, albinus) were randomly divided into eight groups with 10 hemimaxillae in each of the following: control; bleached (Ble, 35% hydrogen peroxide [H2O2]); Ble-1IRL and Ble-1RL (one IRL [808nm, 30s, 3J] or RL [660nm, 15s, 1.5J] application immediately after H2O2); Ble-3IRL and Ble-3RL (three [immediately, 24h, and 48h] IRL or RL applications after H2O2); and 3IRL and 3RL (three IRL or RL applications without bleaching). The rats were euthanized after 2 and 30days for histological evaluation of inflammation (hematoxylin-eosin) and maturation of collagen fibers (picrosirius red). Additionally, the dentin deposition in the specimens obtained at 30days was quantified via microtomography of the pulp chamber volume. Statistical analyses were performed (P < 0.05). Initially, severe damages to the pulp were observed in the Ble and Ble-1RL groups. Ble-1IRL and Ble-3RL groups showed lower inflammation. The bleached groups had a greater amount of mature collagen fibers than the control group. The Ble-3IRL group had a greater number of immature fibers than the Ble group. At 30days, there was an absence of inflammation and equal proportion of mature and immature collagen fibers. All bleached groups showed a reduction in the volume of the pulp chamber. Three consecutive applications of RL and one IRL application can minimize damage to the pulp of bleached teeth, whereas three IRL applications can minimize pulp fibrosis. However, LLLT did not prevent deposition of tertiary dentin. This study describes LLLT protocols capable of minimizing inflammation and maturation of collagen fibers in pulp tissue after dental bleaching. However, the protocols proved insufficient for reducing the formation of tertiary dentin in bleached teeth.

Healing of Skin Wounds in Rats: Influence of Low-Level Laser Therapy, Alone or Combined with Natural Products

Background: A great variety of natural products have been evaluated for the skin wound healing due to anti-inflammatory, antioxidant and antibacterial activities, and procollagen synthesis, of which may be mentioned the honey and propolis. In turn, low-level laser therapy (LLLT) is considered an important tool in the treatment of skin wounds, because of ability to raise the ATP production, to stimulate the microcirculation, and formation of new blood vessels. Therefore,this study aimed to assess the influence of LLLT, alone or combined with natural products, in the healing of excisional skin wounds in rats. Materials, Methods &amp; Results: One hundred twenty-six male Wistar rats, aged 14 weeks, were randomly divided into seven groups (n = 18 per group) according to wound treatments: G1 (negative control): 0.9% saline solution; G2 (positive control): allantoin + zinc oxide ointment; G3: LLLT; G4: mixture of honey + 5% propolis hydroalcoholic solution; G5: LLLT + honey + hydroalcoholic solution of 5% propolis; G6: LLLT + honey in natura; G7: LLLT + 5% propolis hydroalcoholic solution. Six rats from each group were euthanized on the 7th, 14th, and 21th postoperative days. Macroscopic and histological evaluations of wound healing were performed. A decrease in wound area occurred in all groups, but in general G4 had the higher reduction and G1 and G3 had the lower reductions. These findings corresponded to the percentage of wound contraction, since the largest contraction was G4 and the lowest contractions were G1 and G3. Histological analysis showed no significant difference among groups on the 7th postoperative day. On postoperative day 14, a significant decrease in hemorrhage occurred between G1xG4, G1xG5 and G1xG7, and a significant decrease in congestion between G1xG7 and G2xG5. In addition, intensity of the inflammatory infiltrate showed a significant reduction between G1xG7, G2xG7 and G3xG7. On postoperative day 21, a significant changed from mixed to mononuclear inflammatory infiltrate was observed between G1xG3, G1xG4, G1xG6, G1xG7, G2xG3, and G2xG6. Regarding organization of fibroblasts, there were differences between G1xG6 and G1xG7. Discussion: Spite the red laser has been associated to in increase fibroblast proliferation, G3 showed inadequate decrease in wound area and percentage of contraction. Histological examination showed no differences among groups in the inflammatory phase. However, in the proliferative and remodeling phases around days 14 and 21 were found some differences among groups, which may be related to the actions of the natural products, or laser. Studies have shown that honey acts as a repair and anti-inflammatory agent in skin woundthat may be associated to lower hemorrhage in G4 and G4 compared to G1 on day 14. Propolis is related to reduction of free radicals and increasing the amount of collagen, which may have contributed for quality improvement of the inflammatory infiltrate in G4 and G7 compared to G1, and fibroblast organization in G7 at postoperative day 21. In conclusion, macroscopically the mixture of honey + 5% propolis hydroalcoholic solution was the most effective in reducing wound area and increasing wound contraction. However, based on the parameters evaluated histologically, may be highlighted the evolution of the treatments with LLLT + honey, as well as LLLT + 5% propolis hydroalcoholic solution. Keywords: honey, propolis, biomodulation, wound, healing.

HISTOLOGICAL ANALYSIS OF WISTAR RATS SCIATIC NERVES SUBJECTED TO COMPRESSION AND TREATED WITH LOW LEVEL LASER THERAPY AND NEURAL MOBILIZATION

Background: The physical therapy resources, as Low-Level Laser Therapy (LLLT) and neural mobilization are usually used with regenerative purpose and for the relief of symptoms for peripheral nerve injury. However, there is a lack of consensus on its effects as well as its association. Objective: Evaluate the influence of low-level laser therapy (LLLT) associated with neural mobilization (NM) on nerve regeneration of female Wistar rats subjected to sciatic compression. Methods: Twenty four Wistar rats were divided into: G1 (Placebo), G2 (NM), G3 (LLLT) and G4 (NM+LLLT), all animals were subject to compression of the right sciatic nerve. The treatment occurred on the 3 rd , 5 th , 7 th , 10 th , 12 th and 14 th postoperative day (PO). On the 17th PO the animals were euthanized. Histological and morphometric analysis of the right (compression) and the left (control) sciatic nerve were performed. Results: In the morphometric analysis no significant differences between groups, but differences among sides were found. Histological analysis revealed the presence of inflammatory infiltrate and disruption of nerve fibers in the right sciatic nerves. Conclusion: Both techniques used (LLLT and neural mobilization), isolated and associated, on the parameters proposed, were not effective to accelerate the process of nerve regeneration.

Influence of Low Intensity Laser Biomodulation on the Osseointegration of Delayed and Delayed-Immediate Implants

The aim of this study was to compare and contrast the influence of low-level laser therapy (LLLT) on the osseointegration of delayed and delayed-immediate dental implants. Forty implants were installed in the maxillary premolar regions of forty male subjects of age ranged 40-45 years old. Subjects were then randomly divided into four groups (I, II, III, and IV), delayed implant control group, delayed implant laser group, delayed-immediate implant control group, and delayed-immediate implant control group. Following implant insertion, the healing phase of groups (I and III) was left to progress spontaneously. Groups (II and IV) were subjected to low intensity (gallium arsenide diode) laser application with wavelength of 904 nm, an output power of 30 mWatts, and a frequency of 9999 Hz for 3 minutes in three sessions on three alternative days starting from the tenth post-operative day. A six month follow up period was applied radiographically to all subjects of both groups using sequential conventional radiographs. Radiographs were digitized by a professional scanner and bone density was recorded. The results revealed that low intensity laser therapy (LLLT) provided an easy as well as efficient method for accelerating bone healing and improving osseointegration whatever the technique used for implant insertion. The study concluded that laser could be used as additional aid for improving osseointgration and increasing the success rate for implantation protocols.Keywords: Laser, LLLT, Osseointegration, Dental Implant.

Low-level laser therapy as a modifier of erythrocytes morphokinetic parameters in hyperadrenalinemia.

Low-level laser therapy (LLLT) is widely used in clinical practice for treatment of various pathologies. It is assumed that LLLT impact on microcirculation is among the mechanisms underlying its therapeutic effect. The microcirculation disorder is observed in the pathogenesis of any inflammatory process and is significantly influenced by red blood cells (RBCs). On this point, studying the RBCs morphology under the influence of LLLT on alterated organism is of scientific interest and practical importance. The aim of the present study was to analyze the LLLT effect on morphokinetic parameters of RBCs in hyperadrenalinemia. The LLLT effect was analyzed on rats intraperitoneally injected with adrenaline hydrochloride solution (0.1mg/kg). As the comparison groups, the effects of LLLT, adrenaline, or saline injection as well as the parameters of intact animals were studied. LLLT was applied on the occipital region of rats for 10min. The light irradiation with pulse frequency 415Hz at 890nm wavelength and average power density in the plane of the output window at 193μW/cm2 was used. The dynamics of morphological characteristics of RBCs was studied by phase interference microscopy; the RBC electrophoretic mobility was tested by microelectrophoresis technique; photometric analyses of the RBCs amount, hemoglobin content, and osmotic fragility were performed. The adrenaline injection resulted in a significant increase in the amount of RBC pathological forms and a decrease in discocytes and normocytes by more than 50%. An increase in the optical density of RBC phase portraits, a decline in osmotic resistance, and electronegativity of RBC membranes and a reduction of their number in peripheral blood were also registered. The revealed effects persisted for 1week after the adrenaline administration. LLLT did not significantly impact on the RBC parameters 1h after adrenaline injection. However, a day later, LLLT reduced the severity of the adrenaline effect on RBSs, which was manifested in a decreased amount of the pathological forms of RBCs, restored RBC phase portraits, higher electrophoretic mobility and osmotic resistance, and RBSs amount in peripheral blood restored up to the level of intact animals. We suppose that the mechanism of LLLT action is realized both at cellular level through the laser radiation effect on RBC membranes, and at systemic level through the activation of stress-realizing systems of the organism with subsequent limitation of inflammatory response.

Effect of Low-Level Laser on the Healing of Neurosensory Disturbance Following Sagittal Split Ramus Osteotomy: A Double-Blind, Randomized Clinical Trial

Background: Neurosensory disturbances following orthognathic surgery, especially sagittal split ramus osteotomy are quite common. Furthermore improving the injuries to the inferior alveolar nerve following ramus osteotomy is still a challenge. Objectives: This study aims to evaluate the influence of low-level laser therapy (LLLT) on the improvement of neurosensory disturbance following sagittal split ramus osteotomy. Methods: This randomized, double- blinded clinical study was executed in a university-affiliated hospital, Tehran, Iran, during January 2017 and March 2018. Patients underwent sagittal split ramus osteotomy (SSRO) divided into case and control groups. Ten sessions of laser irradiation of 810 nanometers wavelength and power of 70 mW were rendered for eight minutes in the case group, while the patients in the control group were not irradiated. Thermal test, mechanoreceptor sensory tests, and satisfaction of the patients were evaluated during follow up examinations. Mapping of the affected skin area was marked to assess the healing process of the nerve damage. Results: A total of 40 patients were included in the current study followed for a 12-month period. Statistical analysis of extracted data from the two-point discrimination test showed the significant better response of mechanoreceptors among the case group patients rather than the control ones (P value = 0.035). Marking the hyposthetic skin area in the patients that experienced laser therapy demonstrated that almost all of them manifested less sense on the vermilion area (85% in the case group versus 15% in the control group). Despite the control group patients whom on the mental foramen area significantly more paresthesia was experienced. Conclusions: In conclusion, low-level laser therapy following sagittal split osteotomy may be helpful in faster recovery of nerve injuries and higher satisfaction of the patients.

Low-level laser irradiation modifies the effect of hyperglycemia on adhesion molecule levels.

Endothelium plays a key role in maintaining vascular homeostasis by secreting active factors involved in many biological processes such as hemostasis, angiogenesis, and inflammation. Hyperglycemia in diabetic patients causes dysfunction of endothelial cells. Soluble fractions of adhesion molecules like sE-selectin and vascular cell adhesion molecule (sVCAM) are considered as markers of endothelial damage. The low-level laser therapy (LLLT) effectively supports the conventional treatment of vascular complications in diabetes, for example hard-to-heal wounds in patients with diabetic foot syndrome. The aim of our study was to evaluate the effect of low-energy laser at the wavelength of 635nm (visible light) and 830nm (infrared) on the concentration of adhesion molecules: sE-selectin and sVCAM in the supernatant of endothelial cell culture of HUVEC line. Cells were cultured under high-glucose conditions of 30mM/L. We have found an increase in sE-selectin and sVCAM levels in the supernatant of cells cultured under hyperglycemic conditions. This fact confirms detrimental influence of hyperglycemia on vascular endothelial cell cultures. LLLT can modulate the inflammation process. It leads to a decrease in sE-selectin and sVCAM concentration in the supernatant and an increase in the number of endothelial cells cultured under hyperglycemic conditions. The influence of LLLT is greater at the wavelength of 830nm.

Effect of low-level laser therapy on tissue repair after dental extraction in rats administered zoledronic acid and dexamethasone.

Bisphosphonates (BPs) are being increasingly used for the treatment of metabolic and oncological pathologies involving the skeletal system. Because of the severity of the BP associated osteonecrosis of the jaws, the difficulties of treatment, and patient discomfort, additional support methods for their management are needed. Laser therapy has an easy handling, photobiostimulator effect on tissues healing, so it can be considered a preferred therapy. The aim of this study was to evaluate the influence of low-level laser therapy in the 685- and 830-nm wavelength in the healing process of the bone and soft tissues in rats under BP therapy [zoledronic acid (ZA)] and dexamethasone concomitantly that underwent a surgery for the extraction of upper molars. There were statistically significant differences in the clinical evaluation of the wound and the weight of the animals. Regarding the histological evaluation, it was possible to observe the different maturations of the healing stage between groups. The effect of drug therapy with ZA and dexamethasone in the bone tissue repair process induces osteonecrosis of the jaw in rats and slows down the healing process. In the laser groups, at the stipulated dosimetry, a positive influence on the bone and soft tissue repair process was observed.