Different Types Of Lasers Research Articles

Thulium-laser retrograde intra renal ablation of upper urinary tract transitional cell carcinoma: an ESUT Study.

Background Radical nephroureterectomy (RNU) is the gold standard treatment for upper urinary tract urothelial carcinoma (UTUC); however, patients presenting with small low-grade UTUC have been treated by flexible ureteroscopic laser ablation with good outcomes. Different types of laser have been discussed in the literature including Holmium and Neodymium lasers. We aimed to assess the safety and efficacy of Thulium laser (Tm:YAG) in the ureteroscopic ablation of UTUC. Methods A retrospective observational multicentre study of patients diagnosed with papillary UTUC between January 2015 and December 2016 was carried out. All patients underwent ureteroscopic biopsy of the UTUC followed by Tm:YAG ablation. Based on the histopathological grade of the tumor, patients were counseled to undergo either RNU (high-grade tumors) or conservative managementand follow-up (low-grade tumor). Results RNU was performed in 31 patients, while the remaining 47 patients (undergone ™:YAG ablation only) were followed up for a mean of 11.7 months with only 19.2% of patients showing upper tract recurrence and no patients showed postoperative ureteral strictures. Limitations include the short follow-up and retrospective nature of the study. Conclusions On the short term, thulium Laser ablation of UTUC is safe and feasible especially in lowgrade UTUC.

POSSIBILITIES OF IMPROVING THE SHEAR STRENGTH BETWEEN DIFFERENT TYPE OF CEMENT AND ZIRCONIA CERAMICS: LITERATURE REVIEW

Background: Zirconia ceramics are a modern dental material which has a wide range of application in restoration of frontal and distal teeth. This is due to its improved mechanical properties and aesthetics. Aim: This literature review analyses the possibilities for improvement of the bond strength between zirconia ceramics and different types of cement which are used for fixation of prosthetic constructions. Review Results: The evidence from the literature indicates that preliminary treatment of zirconia ceramics increases the bond strength significantly to the cement. In this respect, different methods and materials are used for the treatment of the zirconium dioxide surface. Some of them include only mechanical treatment with diamond burs, a different type of lasers and sandblasting with aluminum oxide. Other methods have chemical action by the use of hydrofluoric acid and fluoride compounds. According to some data, zirconium structure does not allow etching which leads to application of different type of primers for increasing the shear strength. Studies show that silane application significantly improves the shear bond strength to the cement, as well as, zirconium tensile strength. Optimal results are registered with a combination of treatment with mechanical methods and silane application. Conclusion: Preliminary mechanical and chemical treatment of zirconia surface improves the shear bond strength considerably to the cement. The variety of surface treatment methods complicates the establishment of a standard protocol for fixation of zirconium prosthetic constructions.

Effects of laser therapy on periorbital hyperpigmentation: a systematic review on current studies.

Periorbital hyperpigmentation is a problem with complex multifactorial etiology, with early knowledge expanding. The purpose of the present study was to review studies on the efficacy of laser on periorbital hyperpigmentation. A systematic review of the data banks of scientific and research articles including PubMed, Web of Knowledge, Google Scholar, SCOPUS, and Iranian databases including SID and Magiran is performed. The following keywords were used to evaluate existing articles: Periorbital Hyperpigmentation, Periorbital Darkening, Dark Eye Circle, Eye Dark Circle, Infraorbital Hyperpigmentation, Infraorbital Dark Circle, and Laser (1990-2018). Finally, 10 clinical trial articles were included. A total of 2.76% of patients responded poor, 11.4% responded fair to different types of lasers, 45.3% responded good, and 35.9% excellent responded to have been cured. As a long-term effect, less than 1% of patients received a poor score after their laser treatment. Twenty-five percent of the patients showed a fair result. In total, 26.27% of patients achieved good and 43.35% of patients received excellent response from laser treatment on periorbital hyperpigmentation after 4-6months of laser therapy. A large percentage of patients (76.4%) were satisfied with the effect of lasers on the reduction of moderate to high periorbital hyperpigmentation rates in the studies. Laser therapy is an effective and satisfactory therapeutic choice for treatment of periorbital hyperpigmentation. Also, it is safe overall with favorable sustainable results, although the follow-up periods usually last about several months.

Single-Mode Semiconductor Nanowire Lasers With Coupled Cavities.

Semiconductor nanowires are one of the most fascinating topics over the past few decades. As miniaturized coherent light sources, semiconductor nanowires have been attracting tremendous attention in recent years for scientific and technological interest as potential ultra-compact, low cost, high efficiency, and low power consumption. Among different types of lasers, one-dimensional nanowires are of great interest as a promising material for next-generation nanophotonics and nanoelectronics applications due to their unique optical and electrical properties. Semiconductor nanowire lasers with single-mode output are vital in a variety of practical applications ranging from signal processing, spectroscopy, displays, optical sensing, on-chip communications, and biological studies. This article reviews the basic technology and research progress of single-mode semiconductor nanowire lasers. Afterward, the key methods and development of the different types of coupling to achieved single-mode laser output are elaborated. Finally, the challenges faced by each scheme are summarized.

A Study of Laser Effectiveness in Injured Tissues Regeneration

This study aimed to understand the use of low level laser in the regeneration of injured tissues. Also to design our own opinion on the subject, as chemists. Laser is nothing more than a light with very special characteristics that grant it therapeutic properties. We can observe the existence of three different types of laser, being one of them the therapeutic laser, which is used in substitution for medications or along with them. Another type of laser is the surgical one and, in addition to these, there is a diagnostic type. A great advantage is that, instead of taking the medicine, the patient’s own body can be activated by the laser to produce certain substances that can often replace the drugs. This is a literature review emphasizing the use of low level laser. Thus, the reflections from this study can contribute to the amplification of the production of knowledge that aims at the resignification of the use of laser in therapy. Greater attention was given to two types of laser radiation: He-Ne and As-Ga, both presenting a high therapeutic potential in superficial and deep injures. However, the He-Ne laser excels in superficial lesions, whereas the As-Ga laser does so in deep injures, such as articular, muscular, etc.

Perioperative outcomes of frenectomy using laserversusconventional surgery: a systematic review

Introduction:Frenectomy is an oral surgical procedure usually performed with a scalpel. Several authors recently reported the interest of laser, as a minimally invasive and efficient alternative tool to perform frenectomy. This study aimed to compare the perioperative management of patients requiring a frenectomy using scalpelversuslaser.Materials and methods:A systematic review of the literature has been carried out from Pubmed and Scopus databases following PRISMA guidelines. PICO method was used to select the relevant articles. Clinical studies comparing the perioperative outcomes of patients requiring frenectomies using scalpelversuslaser were included.Results:Ten articles involving 375 patients were included. Pre-operative parameter (anxiety before surgery) and per-operative data such as anesthesia, surgery duration, bleeding, suture and difficulty were assessed. The post-operative outcomes investigated were pain, analgesics use, functional discomfort, edema, healing and satisfaction of patients. Laser achieved satisfactory peri-operative outcomes such as shorter operative time, without suturing requirement, as well as less post-operative pain and functional discomfort.Discussion:The low number of eligible studies, the different type of lasers used and heterogeneity across the methodology of the selected studies were the limits of the study.Conclusion:Laser-assisted surgery became an attractive tool to perform oral soft tissue surgery.

15798 Treatment of recalcitrant viral warts using a 1064 nm Nd:YAG laser

Background: Viral warts are benign proliferations of epithelial cells caused by infection by human papilloma virus (HPV) types 1, 2, 4, and 57. The best approach to treatment-refractory warts is unclear. There is a variable treatment modalities regarding the therapies of recalcitrant warts, Laser therapy is considered a promising treatment method for recalcitrant warts. Different types of lasers have been used for treatment of warts. long-pulsed Nd:YAG laser is considered a good treatment modality in resistant plantar warts.

Use of diode laser in soft tissue. Report of 3 cases.

There are various anatomical conditions or mucogingival alterations that can affect the normal functioning and the gingival aesthetics of teeth and dental implants. Although the treatments of these conditions have been traditionally performed with a scalpel, technological development has allowed that they can be now performed with lasers. There are different types of lasers, being the diode one of the most used due to its smaller size, portability, easy configuration, and lower cost. The laser has become more popular in soft tissue surgeries due to its multiple benefits: shorter operating time, control of bleeding and hemostasis, reduction in the amount of anesthesia, possibility of not requiring sutures, and minimization of post-surgical pain and inflammation. The purpose of this work is to present the resolution of three clinical cases which underwent labial frenectomy procedures, removal of gingival melanosis and resection of irritative fibroma using diode laser. To develop all the procedures, a 940 nm diode laser equipment (Biolase®, USA) was used with a power that varied between 2 and 2.5 W in continuous mode, using a 300 µm tip (E 3-4), which was activated before starting. After surgery, biostimulation was carried out to reduce postoperative pain and edema using the pain tip at 4 W for 30 seconds at a distance of 1 cm directly in the operated area in all cases. In all cases, the diode laser allowed a successful result. The procedure was safe, the technique was simple, and the clinical time was short. The postoperative period occurred with the absence of pain or discomfort, generating greater patient satisfaction. It should be noted that the technique depends on the skill of the professional who performs it.

Use of diode laser in soft tissue. Report of 3 cases

There are various anatomical conditions or mucogingival alterations that can affect the normal functioning and the gingival aesthetics of teeth and dental implants. Although the treatments of these conditions have been traditionally performed with a scalpel, technological development has allowed that they can be now performed with lasers. There are different types of lasers, being the diode one of the most used due to its smaller size, portability, easy configuration, and lower cost. The laser has become more popular in soft tissue surgeries due to its multiple benefits: shorter operating time, control of bleeding and hemostasis, reduction in the amount of anesthesia, possibility of not requiring sutures, and minimization of post-surgical pain and inflammation. The purpose of this work is to present the resolution of three clinical cases which underwent labial frenectomy procedures, removal of gingival melanosis and resection of irritative fibroma using diode laser. To develop all the procedures, a 940 nm diode laser equipment (Biolase®, USA) was used with a power that varied between 2 and 2.5 W in continuous mode, using a 300 µm tip (E 3-4), which was activated before starting. After surgery, biostimulation was carried out to reduce postoperative pain and edema using the pain tip at 4 W for 30 seconds at a distance of 1 cm directly in the operated area in all cases. In all cases, the diode laser allowed a successful result. The procedure was safe, the technique was simple, and the clinical time was short. The postoperative period occurred with the absence of pain or discomfort, generating greater patient satisfaction. It should be noted that the technique depends on the skill of the professional who performs it.

Comparative Effectiveness of 755-nm Picosecond Laser, 755- and 532-nm Nanosecond Lasers for Treatment of Café-au-Lait Macules (CALMs): A Randomized, Split-Lesion Clinical Trial.

Many types of lasers have been used to treat café-au-lait macules (CALMs) since the introduction of the selective photothermolysis theory. However, the efficacy and safety of picosecond lasers, compared with those of nanosecond lasers, have not been researched. To compare the efficacy and safety of 755 nm picosecond laser (PS-755 nm), Q-switched (QS) Alexandrite 755 nm nanosecond laser (QS-755 nm), and QS Nd:YAG 532 nm nanosecond laser (QS-532 nm) for treating CALMs. Forty-one patients received several treatments at 3-month intervals. Lesions were divided into two or three approximately equal parts, which were randomly treated with PS-755 nm, QS-755 nm, and QS-532 nm. The safety and efficacy of three lasers were determined based on blinded visual assessments and self-reports of patients three months after the comparative trial. Visual assessment 3 months after the comparative trial revealed that there was no statistically significant difference among the sites treated by QS-755 nm (2.84 ± 1.11), QS-532 nm (2.63 ± 1.06), and PS-755 nm (2.74 ± 1.05) lasers. Five (26.32%) of 19 patients showed lesion recurrence. Adverse effects included acneiform miliaris, hypopigmentation, and hyperpigmentation, which were resolved within 12 months. Five (26.32%) of 19 patients who showed lesion recurrence 1-5 months after laser treatment had lightened or cleared at least 50% of the lesion. 46.67% of patients were satisfied or very satisfied with the outcome of the overall treatment. PS-755 nm, QS-755 nm, and QS-532 nm laser treatments were equally effective in treating and improving CALMs. PS-755 nm caused fewer adverse effects. Individuals can react differently to different types of lasers. Patch tests should be conducted before the treatment. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Experience Treating Earlobe Keloids with Laser Diode 980nm Excision Followed by Triamcinolone Infiltration.

Lasers have a favorable synergistic effect when combined with other modalities of treatment against keloids. Different types of lasers have been used with triamcinolone infiltration, resulting in promising success rates. The purpose of this study is to describe our first experience treating earlobe keloids with 980 nm laser diode excision followed by triamcinolone infiltration and present our outcomes after 24 months of follow-up. A retrospective chart review of 11 patients with 14 earlobe keloids treated with excision using a 980 nm laser diode followed by triamcinolone acetonide infiltration, between January 2015 and May 2016. Database included demographics, Fitzpatrick skin type, laterality, lesion size, and postoperative visits information. Outcomes were assessed in terms of keloid recurrence rates, complications, and patient subjective aesthetical result satisfaction after 24 months of follow-up. All procedures were technically completed, and follow-up accomplished without attrition. One (7.14%) patient experienced keloid recurrence after the third month. Four (28.57%) patients experienced early wound dehiscence, successfully treated with debridement and re-suture. Self-assessment of aesthetical result was considered "very good" in 64.28% of patients. Surgical excision with 980 nm laser diode followed by triamcinolone infiltration is well-tolerated and shows favorable results treating earlobe keloids, and can be considered a first-line treatment. Comparison between different types of lasers and control groups in large clinical trials is warranted in order to obtain strong clinical evidence for clear indications and recommendations. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Application of laser for treatment of cutaneous leishmaniasis: a review of literature.

Cutaneous leishmaniasis (CL) is a major health problem in developing countries with high economic and health impact. Despite suggested treatment for CL, there is still no definite therapy for this infection, and many of these treatments are associated with serious local and systemic side effects. In the current paper, use of different laser types including continuous and fractional CO2, argon, PDL, erbium glass, and Nd:YAG have been reviewed. Based on our review, given the high reported efficacy and low side-effect profile, use of laser can be considered as a good alternative to standard treatment of cutaneous leishmaniasis (CL). Performing more studies using different types of lasers is recommended to evaluate the efficacy of this method for treatment of CL.

Thulium-laser retrograde intra renal ablation of upper urinary tract transitional cell carcinoma: an ESUT Study.

Radical nephroureterectomy (RNU) is the gold standard treatment for upper urinary tract urothelial carcinoma (UTUC); however, patients presenting with small low-grade UTUC have been treated by flexible ureteroscopic laser ablation with good outcomes. Different types of laser have been discussed in the literature including Holmium and Neodymium lasers. We aimed to assess the safety and efficacy of Thulium laser (Tm:YAG) in the ureteroscopic ablation of UTUC. A retrospective observational multicentre study of patients diagnosed with papillary UTUC between January 2015 and December 2016 was carried out. All patients underwent ureteroscopic biopsy of the UTUC followed by Tm:YAG ablation. Based on the histopathological grade of the tumor, patients were counseled to undergo either RNU (high- grade tumors) or conservative management and follow-up (low-grade tumor). RNU was performed in 31 patients, while the remaining 47 patients (undergone Tm:YAG ablation only) were followed up for a mean of 11.7 months with only 19.2% of patients showing upper tract recurrence and no patients showed postoperative ureteral strictures. Limitations include the short follow-up and retrospective nature of the study. On the short term, thulium Laser ablation of UTUC is safe and feasible especially in low-grade UTUC.

Direct laser writing of graphene electrodes

Direct laser writing of graphene electrodes is an emerging research field for the rapid fabrication of two-dimensional carbon electronic materials with wide applications, ranging from supercapacitors and batteries to sensors, electrocatalysts, actuators, etc. Many types of carbon-containing raw materials can be converted to graphene by one-step laser scribing, without complicated chemical synthesis routines, using a variety of lasers. This perspective categorizes the principles of direct laser writing of graphene, according to the different types of raw materials, different types of lasers, and different applications. The future directions of laser synthesized graphene are also discussed.

Effect of laser-activated irrigation on smear layer removal and sealer penetration: An in vitro study.

Introduction:The present study was carried out with the objective of evaluation of efficacy of two root canal irrigants (LARGAL ULTRA and Biopure mixture of tetracycline, acid, and detergent [MTAD]) in smear layer removal and sealer penetration along the canal walls and to apprise any change in their efficacy when they were activated with two different types of lasers (neodymium-doped yttrium aluminum garnet [Nd:YAG] and erbium-doped yttrium aluminum garnet [Er:YAG]). The analysis was done with the help of confocal laser scanning microscope.Materials and Methods:The curved root canals (>20°) from 140 extracted human molars (negative control, n = 20) were prepared to size #25.06 with NaOCl irrigation. Teeth were divided into two experimental groups with sample size 60 each (Group I, II). Groups further divided into subgroups IA, IB, and IC and IIA, IIB, and IIC with sample size twenty each. Group IA, Largal Ultra irrigation without LAI; Group IB, Largal Ultra irrigation with Nd:YAG; Group IC, Largal ultra with Er:YAG; Group IIA, MTAD irrigation without LAI; Group IIB, MTAD irrigation with Nd:YAG; Group IIC, MTAD irrigation with Er:YAG. Teeth were obturated with gutta-percha and fluorescent dye labeled sealer. Transverse sections at 3 mm from root apex were examined with confocal laser scanning microscopy, and the percentage of sealer penetration into dentinal tubules was measured.Statistical Analysis:Analysis of variance calculated (e.g., one-way between-subjects ANOVA) and Tukey's test was performed for each mean comparison.Results:Difference between control and Group IIc (65.48 ± 0.57) was highest, followed by control and Group Ic (54.92 ± 0.57) and minimum between Group Ib and Group IIa (0.23 ± 0.57). Order of percent diffusion in the present study was: Group IIc > Group Ic > Group IIb > Group Ib ≈ Group IIa > Group Ia > Control (P <.001).Conclusions:It was inferred that, among the two irrigating solutions tested, Biopure MTAD is more proficient than Largal Ultra. Laser activation of final irrigating solution has been shown to allow better sealer penetration, with Er:YAG laser being more potent than Nd:YAG laser.

Analyses of optical radiation safety standards for laser illuminated products

AbstractThe high energy density of optical radiation from laser illuminated products may cause eye injury, so it is necessary to study the optical radiation safety standards for these products. The relations of related international and Chinese organizations, such as IEC/TC76, IEC/TC108, IEC/TC110, Chinese technical committee SAC/TC284, and so on, are introduced. The related standards and the relations are surveyed, especially the safety of laser products (IEC 60825) series, the photobiological safety of lamps and lamp systems (IEC 62741) series, and audio/video, information and communication technology equipment—part 1: safety requirements (IEC 62368‐1:2018). As application examples of standards, some specific laser illuminated products, including the laser projector, the laser headlamp and light detection and ranging (LiDAR) used in the vehicle, as well as the evaluation methods for the blue light effect of the display are discussed and analyzed. On the basis of the analyses of the optical radiation safety standards, it is necessary to select or develop appropriate standards for different types of laser illuminated products.

Analysis of Laser Therapy Effects on Squamous Cell Carcinoma Patients: A System Biology Study.

Introduction: The Mechanism of laser therapy and also its safety are 2 important features of the application of different types of lasers in medicine. This study aims to investigate the critically affected genes after the treatment of squamous cell carcinoma patients. Methods: The gene expression profiles of 4 squamous cell carcinoma patients that were treated via chemoradiotherapy (CRT) plus the laser and 3 similar patients without laser exposure from Gene Expression Omnibus (GEO) were downloaded and were screened to find critical genes via network analysis. The STRING database, Cytoscape software, and the Clue GO plug-in of Cytoscape software were used. Results: The genes HSX70 and NCC27 were determined as neighbors and HSPA1B, CLIC1, RAB13, PPIF, and LCE3D as hub genes. The over-expression of LCE3D was interpreted as the side effect of laser therapy. Apoptosis and the cell cycle were the dominant biological processes regulated by the HSP molecules in the laser-treated patients. Conclusion: The laser affected the main biological processes and simultaneously issued side effects.

Efficacy of long-pulsed Nd-YAG laser in the treatment of nail psoriasis: a clinical and dermoscopic evaluation

Background Nail psoriasis (NP) is frequently seen in psoriatic patients. It is difficult to treat and shows unsatisfactory response to topical preparations. Recently, different types of Lasers have been shown to be effective in some nail disorders. Aim The aim was to evaluate the efficacy and safety of long-pulsed Nd: YAG laser 1,064 nm as a method for NP treatment. Methods A prospective intra-patient left-to-right, randomized, placebo-controlled study conducted on 22 patients with bilateral fingernail psoriasis, randomly assigned into right or left-side therapy with either four sessions of long-pulsed Nd:YAG laser once monthly or daily topical placebo for 4 months, followed by 3 months follow-up. Evaluation was done using NP severity index at baseline, second month, fourth month and after follow-up period. Clinical and dermoscopic photographs were taken both at baseline and at 4th month. Results There was a statistically significant improvement in both NP severity index and dermoscopic features in laser side, along with significant difference between laser and placebo side. Nail bed showed obvious improvement than nail matrix. Conclusion Nd:YAG laser represents an effective and safe modality for NP treatment and dermoscopy is a useful tool for treatment efficacy assessment.

Frequency-Modulated Combs Obey a Variational Principle.

Laser dynamics encompasses universal phenomena that can be encountered in many areas of physics, such as bifurcation and chaos, mode competition, resonant nonlinearities, and synchronization-or locking-of oscillators. When a locking process occurs in a multimode laser, an optical frequency comb is produced, which is an optical spectrum consisting of equidistant modes with a fixed phase relationship. Describing the formation of self-starting frequency combs in terms of fundamental laser equations governing the field inside the cavity does not allow one, in general, to grasp how the laser synchronizes its modes. Our finding is that, in a particular class of lasers where the output is frequency modulated with small or negligible intensity modulation, a greatly simplified description of self-locking exists. We show that in quantum cascade lasers-solid-state representatives of these lasers characterized by an ultrashort carrier relaxation time-the frequency comb formation obeys a simple variational principle, which was postulated over 50years ago and relies on the maximization of the laser output power. The conditions for the breakdown of this principle are also experimentally identified, shedding light on the behavior of many different types of lasers, such as dye, diode, and other cascade lasers. This discovery reveals that the formation of frequency-modulated combs is an elegant example of an optimization problem solved by a physical system.

Effects of low level laser therapy in cancer cells-a systematic review of the literature.

The aim of the present study was to conduct a systematic review regarding the use of photobiomodulation (PBM) therapy in tumoral cells, addressing the different types of lasers and parameters used. An electronic search was performed in PubMed/MEDLINE, Cochrane Library, and EMBASE databases. The inclusion criteria were being an in vitro study, with tumoral cells, and have at least one group of treatment with low-power laser and a control group (without treatment). Were excluded studies that used only non-carcinogenic cells, in vivo studies, studies that used high-power laser or the association with photosensitizers. The primary outcome evaluated was the cellular viability, and the secondary outcomes were the apoptosis rate and gene and inflammatory mediators' expression. Nineteen studies were identified among the lists of citations of studies that met the exclusion/inclusion criteria. There is a wide divergence regarding the wavelengths and doses used, as well as the type of laser, and each variation leads to different results, with some studies showing an increase in cell proliferation, while other studies showed a decrease. It is possible to suggest that PBM can be used in cancerous lesions in order to decrease the proliferation of these cells depending on the parameters used; however, the lack of standardization of laser irradiation protocols for in vitro investigations does not allow the establishment of ideal parameters for this purpose. Therefore, PBM should be used with caution in cancer patients until more studies are performed.