Effect of low-level laser therapy on tooth-related pain and somatosensory function evoked by orthodontic treatment

Low-level laser therapy(LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodontic treatment. Forty individuals(12–33 years old; mean ± standard deviations: 20.8 ± 5.9 years) scheduled to receive orthodontic treatment were randomly divided into a laser group(LG) or a placebo group(PG)(1:1). The LG received LLLT(810-nm gallium-aluminium-arsenic diode laser in continuous mode with the power set at 400 mW, 2 J·cm–2) at 0 h, 2 h, 24 h, 4 d, and 7 d after treatment, and the PG received inactive treatment at the same time points. In both groups, the non-treated side served as a control. A numerical rating scale(NRS) of pain, pressure pain thresholds(PPTs), cold detection thresholds(CDTs), warmth detection thresholds(WDTs), cold pain thresholds(CPTs), and heat pain thresholds(HPTs) were tested on both sides at the gingiva and canine tooth and on the hand. The data were analysed by a repeated measures analysis of variance(ANOVA). The NRS pain scores were significantly lower in the LG group(P = 0.01). The CDTs,CPTs, WDTs, HPTs, and PPTs at the gingiva and the PPTs at the canine tooth were significantly less sensitive on the treatment side of the LG compared with that of the PG(P < 0.033). The parameters tested also showed significantly less sensitivity on the nontreatment side of the LG compared to that of the PG(P < 0.043). There were no differences between the groups for any quantitative sensory testing(QST) measures of the hand. The application of LLLT appears to reduce the pain and sensitivity of the tooth and gingiva associated with orthodontic treatment and may have contralateral effects within the trigeminal system but no generalized QST effects. Thus, the present study indicated a significant analgesia effect of LLLT application during orthodontic treatment.Further clinical applications are suggested.

Low-level laser therapy enhances the number of osteocytes in calvaria bone defects of ovariectomized rats

Background : Osteoporosis can make bone repair difficult. Low-level laser therapy( LLLT) has been shown to be a promising tool for bone neoformation. This study aimed to analyze the effect of LLLT on calvaria bone defects of ovariectomized rats using stereology. Methods : Fifty-four Wistar rats were subjected to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups(n = ?6 per group), and 24 hours after the bone defects were created they received three, six or 12 sessions of LLLT at 0, 20 or 30 J/cm 2, using a 780-nm low-intensity GaAlAs laser. One-way ANOVA followed by Tukey ' s post hoc test was used for data processing. A difference of P < 0.05 was considered statistically significant. The parameters evaluated were osteocyte density( Nv_(ost)), total osteocyte number( Nto ost), trabecular surface density( Sv_t), and trabecular surface area( Sa_t). Results : Data obtained showed that Nto ost, Sv t, and Sa t in group G2 rats were significantly different from G1(0 J/cm^2)( P < 0.05). Compared to group G4, G5 presented higher values for the parameters Sv t and Sa t, and G6 presented significantly higher values for almost all the analyzed parameters( Nv _(ost), Nto_(ost), Sv_t, and Sa t)( P < 0.05). Compared to group G7, G8 showed a higher value only for the parameter Sa t, and G9 showed significantly higher values for parameters Nv ost, Nto ost, Sv_t, and Sa_t. Conclusion : We conclude that LLLT stimulated bone neoformation and contributed to an increase in the total number of osteocytes, especially with a laser energy density of 30 J/cm^2 given for six and 12 sessions.

Induction of Autologous Bone-Marrow Stem Cells by Low-Level Laser Therapy Has Beneficial Effects on the Kidneys Post-Ischemia-Reperfusion Injury in the Rat

Acute renal failure has a 50% - 80% mortality rate. Currently, treatment options for this life-threatening disease are limited. Low-level laser therapy (LLLT) has been found to modulate biological activity. The aim of the present study was to investigate the possible beneficial effects of laser application to stem cells in the bone marrow, on the kidneys of rats that had undergone ischemia-reperfusion injury (IRI). IRI was induced by occlusion of the renal artery to 3- and 7-month-old rats for 15 or 30 minutes. In an additional experiment IRI was applied to both kidneys for 20 min each in 2-3-month-old rats. Rats were then divided randomly into two groups of control and laser-treated. Laser therapy (Ga-Al-As 810 nm, 200 mW output for 2 min) was applied to the bone marrow 1 and 7 days post-IRI to the kidneys, and rats were sacrificed 2 weeks later. Histomorphometry and immunohistochemistry were performed on kidney sections and blood markers for kidney function. Quantitative histomorphometric analysis revealed a reduction in dilatation of the renal tubules, restored structural integrity of the renal tubules, and reduced necrosis in the laser-treated rats as compared to the control, non-laser-irradiated group. C-kit positive cell density in kidneys post-IRI and laser-treatment was significantly (p = 0.015) 3.2-fold higher compared to the control group. Creatinine and blood urea nitrogen content were significantly lower in the laser-treated rats as compared to control. It is concluded that LLLT application to the bone marrow (BM) causes a significant increase in the density of mesenchymal stem cells in the kidneys post-IRI, probably by induction of stem cells in the BM, which subsequently migrate to the IRI kidney, significantly reducing the pathological features of the kidney and increasing kidney function post IRI.

Low-Level Laser Therapy versus Four Layers Compression Technique in the Treatment of Venous Ulcers

Objective: The aim of the study is to evaluate the effect of low-level laser therapy in comparison to compression bandage therapy in the treatment of venous ulcers. Subjects & Methods: This study was carried out in the period from March 2013 to March 2014. The study included 40 adult patients with a diagnosis of venous ulcer classified as C6 according to the clinical classification of CEAP classification. The patients were divided into 2 groups: the first one included 20 patients treated by low-level laser therapy at the Rheumatology and Rehabilitation department, and the second group included 20 patients in whom we use four layers compression bandaging at the vascular surgery department. Results: 32 ulcers were treated in group I and 35 ulcers were treated in group II. The patients of group I were 7 (35%) females and 13 (65%) males, their age range were (24 - 56) years. The patients of group II were 11 (55%) males and 9 (45%) females;their age ranges were (32 - 50) years. Measurements of the ulcers size by (cm2) were taken at the beginning of therapy, at 1 month, at 2 months and at 3 months later on. The calculation of the area of the ulcer was done by using the graph papers to document the ulcer’s perpendicular linear dimensions. According to the size of the ulcer, some ulcers heal within 1 month (15.6%) ulcers in group I, and (28.5%) in group II. Some ulcers heal within 2 months (28%) in group I, and (37%) in group II. The remaining ulcers heal within 3 months or more which are (56%) ulcers in group I, and (34.2%) ulcers in group II. The recurrence rate of chronic venous leg ulcer in compression bandage technique used in group II was the least one as the total number of recurrent cases were 5 (25%), followed by laser therapy used in group I. Conclusion: There was no significant efficacy of the low-level laser therapy over the four layers compression technique in the management of chronic venous ulcers.

Effects of wavelength,beam type and size on cerebral low-level laser therapy by a Monte Carlo study on visible Chinese human

Low-level laser therapy(LLLT)has been clinically utilized for many indications in medicine requiring protection from el/issue death,stimulation of healing and repair of injuries,pain reduction,swelling and inflammation.Presently,the use of LLLT to treat stroke,traumnatic brain injury and cognitive dysfunction are attracting growing interest.Near infrared light is capable of penetrating into the cerebral cortex,allowing noninvasive treatments to be caried out with few treatment-related adverse events.Optimization of LLLT treatment flfect is a crucial isse of this field;however,only a few experimental tests on mice for wavelength selection have been reported.We addressed this ssue by low-ost,straightforward and quantitative comparisons on light dosage distribution within visible Chinese human head by Monte Carlo modeling of near infrared light propagation.Optimized selection in wavelength,beam type and size were given based on comparisons among frequently used setups(ie,wavelengths:660,810 and 980 nm;beam type:Gaussian and flat beamn;beam diameter:2,4 and 6 cm).This study provided an fficient way for guiding the optimization of LLLT setup and selection on wavelength,beam type and size for clinical brain LLLT.

Effect of Intrauterine Laser Therapy at the IVF Success Rate on Infertile Patients with a History of IVF Failure: A Pilot Non-Blinded Study

Backgrounds: While there’s developing proof aimed toward improving embryo implantation thru a focal point on great development, restrained studies have been performed on enhancing endometrial receptivity. Intrauterine Laser Therapy (LT) can be powerful in selling endometrial cell proliferation, therefore enhancing the achievement of assisted reproductive techniques (ART). The contemporary look at aimed to research the effectiveness of effective intrauterine lasers in growing endometrial thickness and the achievement of being pregnant rate. Materials and Methods: In the current clinical randomized trial (RTC) study, the infertile women (20 - 42 years old) referred to the infertility clinic in 2023-2024 who were candidates for IVF treatment with recurrent implantation failure (RIF) history were included. The patients were divided into two main groups: the intervention group;low level laser therapy (LLLT) after hormone administration) (n = 52) and the control group (hormone administration without LT) (n = 52). The IVF success rate and change in endometrial thickness before and after the LT were compared in groups. Results: There was a significant difference between groups (p Conclusion: It appears that the incorporation of Intrauterine LT in the realm of infertility could significantly impact as a novel supplementary treatment in improving endometrial receptivity and pregnancy rate.

Effects of Kangfuxin Solution (康复新液) Combined with Low-level Laser on Cytokines and Immune Function in Patients with Radiation-induced Oral Mucositis

Objective:To investigate the effect of Kangfuxin Solution(康复新液)combined with low-level laser therapy(LLLT)on cytokines and immune function in patients with radiation-induced oral mucositis.Methods:There were 84 nasopharyngeal carcinoma patients with oral mucositis after intensity-modulated radiation therapy(IMRT)were randomly divided into the control group(CG)and the observation group(OG),with 42 cases in each group.The CG was given LLLT,and the OG was treated with Kangfuxin Solution in addition to LLLT for 10 consecutive days.The healing time of oral mucosa,mucositis grading,oral pain scores,cytokines(interleukin-6,interleukin-1βand tumor necrosis factor-α)and T lymphocyte subsets were compared between the 2 groups before and after treatment.Results:The healing time of oral mucosa in the OG was(6.8±1.4)d,which was significantly shorter than(8.6±1.9)d in the CG(t=4.943,P<0.01).After treatment,the grading of oral mucositis in the OG was better than that in the CG,with a statistically significant difference(Z=2.942,P<0.05).The oral pain scores of the OG was lower than that in the CG at different time points after treatment,and the difference was statistically significant(t=8.207,11.017,P<0.01).After treatment,the levels of IL-6,IL-1βand TNF-αin peripheral blood of the OG were significantly lower than those in the CG(t=5.217,2.775,4.053,P<0.01).There were statistically significant differences in CD4+,CD8+and CD4+/CD8+between the OG and the CG after treatment(t=5.692,6.093,3.658,P<0.01).Conclusion:Kangfuxin Solution combined with LLLT can significantly shorten the healing time of oral mucosal,reduce the grading of oral mucositis,relieve oral pain,reduce inflammatory response and improve the immune function of patients.

Axial length shortening in myopic children with Stickler syndrome after repeated low-level red-light therapy

AIM:To report the myopia-controlling effect of repeated low-level red-light(RLRL)therapy in patients with Stickler syndrome(STL),an inherited collagenic disease typically presenting with early onset myopia.METHODS:Three STL children,aged 3,7,and 11y,received RLRL therapy throughout the follow-up period of 17,3,and 6mo,respectively after exclusion of fundus anomalies.Data on best-corrected visual acuity(BCVA),intraocular pressure,cycloplegic subjective refraction,ocular biometrics,scanning laser ophthalmoscope,optical coherence tomography,genetic testing,systemic disease history,and family history were recorded.RESULTS:At the initiation of the RLRL therapy,the spherical equivalent(SE)of 6 eyes from 3 patients ranged from-3.75 to-20.38 D,axial length(AL)were from 23.88 to 30.68 mm,and BCVA were from 0.4 to 1.0(decimal notation).Myopia progression of all six eyes slowed down after RLRL therapy.AL in five out of the six eyes shortened-0.07 to-0.63 mm.No side effects were observed.CONCLUSION:Three cases of STL whose progression of myopic shift and AL elongation are successfully reduced and even reversed after RLRL therapy.

Femtosecond laser ultrafast photothermal exsolution

Exsolution,as an effective approach to constructing particle-decorated interfaces,is still challenging to yield interfacial films rather than isolated particles.Inspired by in vivo near-infrared laser photothermal therapy,using 3 mol%Y_(2)O_(3)stabilized tetragonal zirconia polycrystals(3Y-TZP)as host oxide matrix and iron-oxide(Fe3O4/γ-Fe_(2)O_(3)/α-Fe_(2)O_(3))materials as photothermal modulator and exsolution resource,femtosecond laser ultrafast exsolution approach is presented enabling to conquer this challenge.The key is to trigger photothermal annealing behavior via femtosecond laser ablation to initialize phase transition from monoclinic zirconia(m-ZrO_(2))to tetragonal zirconia(t-ZrO_(2))and induce t-ZrO_(2)columnar crystal growth.Fe-ions rapidly segregate along grain boundaries and diffuse towards the outmost surface,and become‘frozen’,highlighting the potential to use photothermal materials and ultrafast heating/quenching behaviors of femtosecond laser ablation for interfacial exsolution.Triggering interfacial iron-oxide coloring exsolution is composition and concentration dependent.Photothermal materials themselves and corresponding photothermal transition capacity play a crucial role,initializing at 2 wt%,3 wt%,and 5 wt%for Fe3O4/γ-Fe_(2)O_(3)/α-Fe_(2)O_(3)doped 3Y-TZP samples.Due to different photothermal effects,exsolution states of ablated 5 wt%Fe_(3)O_(4)/γ-Fe_(2)O_(3)/α-Fe_(2)O_(3)-doped 3Y-TZP samples are totally different,with whole coverage,exhaustion(ablated away)and partial exsolution(rich in the grain boundaries in subsurface),respectively.Femtosecond laser ultrafast photothermal exsolution is uniquely featured by up to now the deepest microscale(10μm from 5 wt%-Fe_(3)O_(4)-3Y-TZP sample)Fe-elemental deficient layer for exsolution and the whole coverage of exsolved materials rather than the formation of isolated exsolved particles by other methods.It is believed that this novel exsolution method may pave a good way to modulate interfacial properties for extensive applications in the fields of biology,optics/photonics,energy,catalysis,environment,etc.

Roles of reinforced nerve conduits and low-level laser phototherapy for long gap peripheral nerve repair

Peripheral nerve injuries are common in clinical practice because of traumas such as crushing and sectioning. Lesions of the nerve structure result in lost or diminished sensitivity and/or motor activity in the innervated territory. The degree of lesion depends on the specific nerve involved, the magnitude and type of pres- sure exerted, and the duration of the compression. The results of such injuries commonly include axonal degeneration and retro- grade degeneration of the corresponding neurons in the spinal medulla, followed by very slow regeneration （Rochkind et al., 2001）. The adverse effects on the daily activities of patients with a peripheral nerve injury are a determining factor in establishing the goals of early recovery （Rodriguez et al., 2004）.

Application of Well-Known Antiviral Drugs in the Field Formed by the Unexplained Properties of Low-Level Laser Radiation in Therapy of Covid-19 and Chronic Viral Hepatitis

Low-level laser therapy (LLLT) or cold laser has been used in medicine for several decades. However, the method utilizes a direct contact of the light beam with a patient. Further research resulted in development of another method that enables remote transmission of the pharmacological properties of a medicament into a human body with the application of low-level laser radiation as the light source. 18 patients with different viral diseases were treated with the antiviral drugs placed into the field formed by the unexplained properties of low-level laser radiation of the “device for transfer of the pharmacological properties of a drug into the patient’s body”. This resulted in improvement of the patient’s condition, the absence of side effects and adverse reactions when using drugs in the proposed device and shortened therapy period for patients with chronic hepatitis C infection and Covid-19 patients. The long-term follow-up of the patients with chronic hepatitis B infection showed that hepatitis B virus remained at low replication levels under the influence of the therapy, which made it possible to avoid such formidable complications of the disease as cirrhosis of the liver and liver cancer.

Photobiomodulation with Super-Pulsed Laser Shows Efficacy for Stroke and Aphasia: Case Studies

Background: Brain disorders have become more and more common today, due to both the aging population and the ever-expanding sports community. However, a new therapeutic technology called photobiomodulation (PBM) is giving hope to thousands of individuals in need. Traumatic brain injury (TBI), dementia, post traumatic stress (PTSD) and attention deficit (ADD) disorders are in many cases quickly and safely improved by PBM. PBM employs red or near-infrared (NIR) light (600 - 1100 nm) to stimulate healing, protect tissue from dying, increase mitochondrial function, improve blood flow, and tissue oxygenation. PBM can also act to reduce edema, increase antioxidants, decrease inflammation, protect against apoptosis, and modulate the microglial activation state. All these effects can occur when light is delivered to the head, and can be beneficial in both acute and chronic brain conditions. Methods: In this case series, we used a high power, FDA-approved superpulsed laser system applied to the head to treat four chronic stroke patients. Patients received as few as three 6 - 9 minute treatments over a one-week period. The follow up time varied, but in one case was two years. Results: Patients showed significant improvement in their speech and verbal skills. Improvements were also noticed in walking ability, limb movement, less numbness, and better vision. Conclusion: The use of PBM in stroke rehabilitation deserves to be tested in controlled clinical trials, because this common condition has no approved pharmaceutical treatment at present.

Deep-Tissue Photothermal Therapy Using Laser Illumination at NIR-Ⅱa Window

Photothermal therapy(PTT)using near-infrared(NIR)light for tumor treatment has triggered extensive attentions because of its advantages of noninvasion and convenience.The current research on PTT usually uses lasers in the first NIR window(NIR-I;700–900 nm)as irradiation source.However,the second NIR window(NIR-II;1000–1700 nm)especially NIRIIa window(1300–1400 nm)is considered much more promising in diagnosis and treatment as its superiority in penetration depth and maximum permissible exposure over NIR-I window.Hereby,we propose the use of laser excitation at 1275 nm,which is approved by Food and Drug Administration for physical therapy,as an attractive technique for PTT to balance of tissue absorption and scattering with water absorption.Specifically,CuS-PEG nanoparticles with similar absorption values at 1275 and 808 nm,a conventional NIR-I window for PTT,were synthesized as PTT agents and a comparison platform,to explore the potential of 1275 and 808 nm lasers for PTT,especially in deep-tissue settings.The results showed that 1275 nm laser was practicable in PTT.It exhibited much more desirable outcomes in cell ablation in vitro and deep-tissue antitumor capabilities in vivo compared to that of 808 nm laser.NIR-IIa laser illumination is superior to NIR-I laser for deep-tissue PTT,and shows high potential to improve the PTT outcome.

Efficacy of super-pulsed 905 nm Low Level Laser Therapy (LLLT) in the management of Traumatic Brain Injury (TBI): A case study

Traumatic brain injury is a major health concern worldwide with massive financial and social impact. Conventional treatments primarily focus on the prevention of further damage to the brain parenchyma, while failing to address the already existent symptoms. Previous clinical studies have shown that Low Level Laser Therapy (LLLT) can significantly reduce pain and induce temporary vasodilation in capillaries, which the authors hypothesize can be used to improve the quality of life in TBI patients by treating their current symptoms, which are predominately migraine-like headaches. This case report illustrates the use of LLLT in the treatment of a patient with a TBI and the great clinical success achieved in the reduction of pain, as measured by VAS—achievable within five treatments of 10 minutes in duration.

Treatment effects and periodontal status of chronic periodontitis after routine Er:YAG laser-assisted therapy

BACKGROUND Routine preclinical interventions for patients with chronic periodontitis such as supragingival cleaning and subgingival curettage,establishing a balanced occlusal relationship,and irrigation with 3%hydrogen peroxide can relieve the symptoms to some extent.However,there is room for improvement in the overall effect.For example,Er:YAG lasers can quickly increase the temperature of the irradiated tissue,effectively eliminate dental plaque and calculus,reduce periodontal pockets,adjust periodontal microecology,and reduce the gingival sulcus.The content of factors in the liquid,and then achieve the purpose of treatment.AIM The aim was evaluate the effect of Er:YAG laser-assisted routine therapy on the periodontal status in chronic periodontitis.METHODS Between October 2018 and January 2020,106 patients with chronic periodontitis in our hospital were randomly assigned to either the study or control group,with 53 patients in each group.The control group underwent routine therapy,and the study group underwent Er:YAG laser therapy in addition to routine therapy.We evaluated the treatment outcome in both groups.Periodontal status was determined by clinical attachment loss(CAL),gingival index(GI),periodontal probing depth(PD),dental plaque index(PLI),and sulcular bleeding index(SBI),inflammatory factors in the gingival crevicular fluid,tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),IL-8],and colony forming units(CFUs).RESULTS Total effectiveness in the study group(94.34%)was higher than that in the control group(79.25%,P<0.05).The clinical parameters in the study group(PD,5.28±1.08 mm;CAL,4.81±0.79 mm;SBI,3.37±0.59;GI,1.38±0.40;PLI,2.05±0.65)were not significantly different from those in the control group(PD,5.51±1.14 mm;CAL,5.09±0.83 mm;SBI,3.51±0.62;GI,(1.41±0.37;PLI,1.98±0.70)before treatment(P>0.05).However,after treatment,the parameters in the study group(PD,2.97±0.38 mm;CAL,2.71±0.64 mm;SBI,2.07±0.32;GI,0.51±0.11;PLI,1.29±0.34)were lower than those in the control group(PD,3.71±0.42 mm;CAL,3.60±0.71 mm;SBI,2.80±0.44;GI,0.78±0.23;PLI,1.70±0.51)(P<0.05).Differences in crevicular TNF-α,IL-6,and IL-8 levels in the study(TNF-α,7.82±3.43 ng/mL;IL-6,11.67±2.59 ng/mL;IL-8,12.12±3.19 pg/mL)and control groups(TNF-α,9.06±3.89 ng/ml,IL-6,12.13±2.97 ng/mL,IL-8,10.99±3.30 pg/mL)before therapy(P>0.05)were not significant.Following treatment,the parameters were significantly lower in the study group(TNF-α,2.04±0.89 ng/mL;IL-6,4.60±1.26 ng/mL;IL-8,3.15±1.08 pg/mL)than in the control group(TNF-α,3.11±1.07 ng/mL;IL-6,6.25±1.41 ng/mL;IL-8,4.64±1.23 pg/mL,P<0.05).The difference in the CFU of the study group[(367.91±74.32)×104/mL and control group(371.09±80.25)×104/mL]before therapy was not significant(P>0.05).The CFU decreased in both groups following therapy,however,the CFU values were lower in the study group[(36.09±15.26)×104/mL]than in the control group[(45.89±18.08)×104/mL](P<0.05).CONCLUSION Combining Er:YAG lasers with routine measures significantly improved the overall periodontal therapy outcomes by improving periodontal status and reducing oral levels of inflammatory factors and CFUs.

Effect of low level laser therapy on dental pulp during orthodontic movement

AIM: To validate the protocol described here to be used in future clinical trials related to the effect of laser therapy on dental pulp. METHODS: Histologically treated samples from eight human healthy premolar teeth obtained from the middle root level were distributed in four groups: group 1(G1) absolute control; group 2(G2) only laser irradiation; group 3(G3) exposed only to orthodontics; and group 4(G4) treated with orthodontics and laser. Laser treatment was performed at 830 nm wavelength, 100 mW(energy 80 J/cm2, 2.2 J), for 22 s in the vestibular surface and 22 s in the palatal surface, 1 mm away from the dental root mucosa. Three staining methods were performed: hematoxylin-eosin(HE), Masson's Trichrome method and Gomori's method.RESULTS: The pulp histology parameters were evaluated and the results classified in to 3 parts: an inflammatory response, soft tissue response(dental pulp) and hard tissue response(dentin and predentin). There was no inflammation(chronic or acute) in any of the evaluated groups. The zones of pulp necrosis were found in one premolar of G3 and in one of G4; in groups G2 and G4 there was higher angiogenesis than in the other two groups. G4 group presented the highest level of vascularization. A reduced nerve density was observed in G3. A G2 specimen showed increased nerve density. A higher rate of calcification was observed in G1 compared to G2. Denticles, either real or false, were observed in G1, G2 and G3. Sclerosis of dentin and focal dentin loss was observed among all the groups. Secondary dentin was present in one sample in G1 and G2. A necrosis zone was found in one sample of G3 and G4. No differences between groups were observed in the odontoblast irregularity layer but the layer was wider in the group treated with laser only. A notable difference was detected in reduction of the cell-free layer between the groups G1 and G4. The findings in pulp tissue favor its adaptative response against dental movement induced by orthodontics. No definitive conclusions may be derived as this is a pilot study. CONCLUSION: The protocol described here was shown to be an effective method to evaluate changes in dental pulp submitted to low level laser in teeth under orthodontic movement.

Neuroimmunomodulatory effects of transcranial laser therapy combined with intravenous tPA administration for acute cerebral ischemic injury

At present, the only FDA approved treatment for ischemic strokes is intravenous administration of tissue plasminogen activator within 4.5 hours of stroke onset. Owing to this brief window only a small percentage of patients receive tissue plasminogen activator. Transcranial laser therapy has been shown to be effective in animal models of acute ischemic stroke, resulting in significant improvement in neurological score and function. NEST-1 and NEST-2 clinical trials in human patients have demonstrated the safety and positive trends in efficacy of transcranial laser therapy for the treatment of ischemic stroke when initiated close to the time of stroke onset. Combining intravenous tissue plasminogen activator treatment with transcranial laser therapy may provide better functional outcomes. Statins given within 4 weeks of stroke onset improve stroke outcomes at 90 days compared to patients not given statins, and giving statins following transcranial laser therapy may provide an effective treatment for patients not able to be given tissue plasminogen activator due to time constraints.

Variable spot size optical system for a dual-wavelength laser therapy device

The majority of existing high-power laser therapeutic instruments employ a single wavelength for a single target;thus,they do not meet the requirements for clinical treatment.Therefore,this study designs an optical system for a dual-wavelength high-power laser therapeutic device with a variable spot size.The waist of the short arm of the optical cavity and the G1G2 parameter(G-parameter equivalent cavity method)is calculated using MATLAB software,the spot size and divergence angle on the lens are calculated using an ABCD matrix,and the distance between the treatment spot at different spot sizes and the transformation lens is calculated in order to design the treatment handpiece.Experiments are conducted to analyze the stability at an output power of 532 nm before beam combination and the power loss after beam combination.The results show that the output power stability of the 532-nm beam varies by less than 2%over 150 min,and the loss of both wavelengths is less than 20%,which meets the clinical requirements of the system.The safety performance can meet the requirements of national general standards for medical electrical safety.The proposed dual-wavelength laser therapy instrument has both visible wave and near-infrared wave characteristics;thus,it can accurately target both superficial vessels and vessels with a larger diameter and deeper position.This therapeutic device has the advantages of simple operation,stable and reliable laser output,high security and strong anti-interference ability,and meets the comprehensive clinical treat-ment demands of vascular diseases.

Liver-directed therapies for liver metastases from neuroendocrine neoplasms:Can laser ablation play any role?

Aggressive cytoreduction can prolong survival in patients with unresectable liver metastases(LM)from neuroendocrine neoplasms(NEN),and minimally invasive,liver-directed therapies are gaining increasing interest.Catheter-based treatments are used in disseminated disease,whereas ablation techniques are usually indicated when the number of LM is limited.Although radiofrequency ablation(RFA)is by far the most used ablative technique,the goal of this opinion review is to explore the potential role of laser ablation(LA)in the treatment of LM from NEN.LA uses thinner needles than RFA,and this is an advantage when the tumors are in at-risk locations.Moreover,the multi-fiber technique enables the use of one to four laser fibers at once,and each fiber provides an almost spherical thermal lesion of 12-15 mm in diameter.Such a characteristic enables to tailor the size of each thermal lesion to the size of each tumor,sparing the liver parenchyma more than any other liver-directed therapy,and allowing for repeated treatments with low risk of liver failure.A recent retrospective study reporting the largest series of LM treated with LA documents both safety and effectiveness of LA,that can play a useful role in the multimodality approach to LM from NEN.

Laser therapy versus intravitreal injection of anti-VEGF agents in monotherapy of ROP:a Meta-analysis

AIM:To compare the efficacy and safety between laser therapy and anti-vascular endothelial growth factor(VEGF)agents intravitreal injection monotherapy in type-1 retinopathy of prematurity(ROP)and aggressive posterior retinopathy of prematurity(APROP).METHODS:A systematic literature search was performed in PubMed,Cochrane Library,and Embase for original comparable studies.We included studies that compare laser therapy and intravitreal injections of anti-VEGF agents monotherapy in ROP regardless of languages and publication types.RESULTS:Complication incidence was significantly higher in laser therapy group(OR:0.38;95%CI:0.19-0.75;P=0.005).Spherical equivalent(SE)was higher in laser therapy[weighted mean difference(WMD):2.40,95%CI:0.88-3.93;P=0.002].The time between treatment and retreatment was longer in laser therapy group(WMD:8.45,95%CI:5.35-11.55;P<0.00001).Recurrence incidence(OR:0.97;95%CI:0.45-2.09;P=0.93)and retreatment incidence(OR:1.24;95%CI:0.56-2.73;P=0.59)were similar in two approaches.Subgroup analysis between type-1 ROP and APROP was not significant except SE reported in the included studies(P<0.0001).CONCLUSION:This Meta-analysis outcome indicates anti-VEGF agents are as effective as laser treatment,and safer than laser in type-1 ROP and APROP.The degree of myopia in APROP is higher than type-1 ROP.More randomized controlled trials in large sample size should be conducted in the future.