Different Types Of Lasers Research Articles

Different laser approaches in treatment of peri-implantitis: a review

Peri-implantitis (PI) is one of the peri-implant diseases that causes destructive inflammatory process of the hard and soft tissues surrounding the implant. Recently, several types of lasers have been proven to be effective in PI. Despite the increase of scientific publications on laser treatment in PI, the best type of laser treatment is not evaluated until now. The primary aim of our systematic review is to provide a comprehensive review on the effect of different types of lasers that were used as a treatment modality for patients with peri-implantitis concerning the most effective type of laser in this field. We used databases from scientific websites such as PubMed/Medline, Scopus, and Google Scholar to get related articles about this subject. The research process involved specific key words “peri-implantitis”-laser treatment”-peri-implantitis treatments”. We were more concerned about English human published studies including clinical trials, case-control, and case series of laser therapy in peri-implantitis. Our initial research yielded 174 articles. After scanning and screening the published articles, we excluded 152 articles; in total, 22 articles were included in this review. We concluded that the determination of the optimal laser treatment for peri-implantitis is recondite due to the disharmony of results that have been documented. However, if lasers are not used according to proper protocols with proper temperatures, a damage can occur to the implant and peri-implant tissues.

Laser frequency stabilization based on a universal sub-Doppler NICE-OHMS instrumentation for the potential application in atmospheric lidar

Abstract. Lidar is an effective tool for high-altitude atmospheric measurement in which a weak absorption line for the target gas is selected to ensure a large optical depth. The laser frequency stabilization to the line center is required, and a sub-Doppler (sD) spectroscopy of the target line is preferred as a frequency reference. In this paper, a novel universal sD noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) instrumentation based on a fiber-coupled optical single-sideband electro-optic modulator (f-SSM) for the potential application in atmospheric lidar for different target gases with different types of lasers is reported. The f-SSM can replace all frequency actuators in the system, so as to eliminate the individual design of feedback servos that often are tailored for each laser. The universality of the instrumentation was demonstrated by the alternative use of either an Er-doped fiber laser or a whispering-gallery-mode laser. Then the instruments based on both lasers were used to produce the sD signals of acetylene, which worked as a frequency reference to stabilize the laser. By performing the lockings, relative frequency stabilizations of 8.3×10-13 and 7.5×10-13 at an integration time of 240 s were demonstrated.

Studies on laser ablation of silicon using near IR picosecond and deep UV nanosecond lasers

Micromachining and other processing of different materials using lasers have been the focus of a large number of investigations in recent years. In this study, we investigate the interactions of two different lasers with crystalline silicon in air. The first laser is a solid state Ti:sapphire laser that has a pulse width of ∼110 ps and emits radiation of a wavelength in the near infrared (IR) region of 785 nm. The second laser is an excimer laser that emits radiation in the deep ultraviolet region (DUV) at a wavelength of 193 nm and has a pulse width of ∼ 4 ns. The excimer laser has a flat-top beam profile while the picosecond laser has a Gaussian beam profile. A series of craters was produced on a crystalline silicon wafer at different fluence, repetition rate, and number of pulses, and the resultant craters were characterized offline for surface morphology and ablation rate using optical and scanning electron microscopy. At low fluence, ablation with the excimer laser produced clean craters with minimal ejection of molten material. Increasing the fluence increased the amount of molten material deposited around the ablation crater, as well as the crater depth. Particles of different shapes and sizes with distributions depending on the number of laser pulses and laser fluence were observed around the ablation craters. Ablation rate was found to be dependent on the repetition rate of the excimer laser. Craters produced by picosecond laser pulses showed surface morphology and ablation rate differences from those of craters produced by excimer laser pulses. The differences in crater morphology, ablation rate, and ablation threshold observed using the two different types of laser can be attributed to differences in the properties of the two laser beams.

The effect of photobiomodulation therapy in the management of alveolar osteitis after tooth extraction: a scoping review

This scoping review evaluated the effects of photobiomodulation therapy (PBMT) in treatment of alveolar osteitis (AO) (dry socket) after the tooth extraction. This search was carried out using the MEDLINE/PubMed database, up to June 2017. The articles were selected focusing the effects of the PBMT in the management of AO after tooth extraction. Three prospective randomized clinical studies were selected. All articles were conducted on systemically healthy adult humans. The PBMT was performed on 105 patients, while the mean age ranged 32.85 years, including males and females. The laser used in these studies ranged from 660 to 2780 nm wavelengths, while the diode laser was the most used (808 nm and 810 nm) with the laser power ranging from 0.1 to 1 W. All laser-treated groups showed positive effects compared with other groups, and there were no adverse or negatives effects reported. Within the limitation of this scoping review, PBMT showed to be significant and faster in the decrease of pain and swelling. The authors also observed an increase in the healing process when PBMT was used in AO treatment. The dry socket irrigation for the debris remotion plays an important role in any chosen treatment for AO. Further clinical studies should be made not only to elaborate a PBMT protocol for treatment of this clinical situation but also to prevent it. The protocols should contain different types of laser to take all therapeutic benefits from each one.

Comparative study of the effect of laser irradiation and acid etching surface treatment on bonding of some dental restorative materials To dentin surface

This study was carried out to evaluate the effect of acid etching versus laser etching of dentin surface on the bonding of Composite and Compomer restorative materials to dentin surface by studying microleakage at the dentin-filling interface, compositional analysis of dentin surface, and Scanning Electron Microscopic (SEM) study of the bonding area. 120 freshly extracted premolar teeth were divided according to surface treatment into three groups. Group I (Acid etching group) contained thirty teeth. Twenty teeth were selected to assess microleakage by forming standardized class V cavity on the buccal surface of the selected teeth. Then, teeth were subdivided into two subgroups with 10 teeth in each. Subgroup (i) delivered composite filling while subgroup (ii) delivered compomer filling according to manufacturer instructions. microleakage at the dentin-filling interface of teeth was examined using dye penetration method. dye penetration scores at occlusal and gingival margins were recorded and tabulated. Five dentin surfaces of five teeth from group I were etched by acid then prepared for compositional analysis of dentin surface by Infra-Red (IR) Spectroscopy. Another Five dentin surfaces were etched by acid then prepared for (SEM) assessment. Group II (Laser etching group) contained ninety teeth, twenty teeth were used for assessing microleakage after laser etching taking similar steps to that of acid etching. Thirty dentin surfaces of thirty teeth were etched by laser with different parameters then prepared for compositional analysis of dentin surface by IR Spectroscopy. Thirty dentin surfaces of thirty teeth were etched by laser with different parameters then prepared for SEM assessment. Group III (Untreated group) contained ten teeth that were left untreated. Five dentin surfaces of five teeth were subjected to IR Spectroscopy assessment. Five dentin surfaces of five teeth were prepared for SEM assessment. The results revealed that acid etching of dentin surface resulted in significant less leakage compared to laser etching. IR Spectroscopy revealed changes in dentin surface structure indicating that there was a reaction occurred by the acid and laser etching. SEM assessment showed more openings of dentinal tubules in case of acid etching, while in case of laser etching, there were a surface structural changes with a melting and fusion dentin surface. Acid etching of dentin gives better results on the bonding of Composite and Compomer filling materials than laser etching and thus gives more successful clinical condition. Further investigations are needed by using different types of laser to get more benefit from applications of laser clinically.

Recurrent Oral Ulcers: current and future therapeutic approaches

Recurrent Oral Ulcers: current and future therapeutic approaches

Discrimination of cancerous and healthy colon tissues: A new laser-based method.

Femtosecond (fs) Laser Ionisation Mass Spectrometry (fs-LIMS) on colon tissues are described and investigated using ionization/fragmentation processes in details to present a new application in this study. Linear Time of Flight (L-TOF) mass analyzer was utilized to investigate paraffin-embedded human tissue in this study. The effect of fs laser intensity on the spectral characteristics was investigated and interpreted due to mass spectra obtained using 800 nm wavelength with 90 fs pulses at 1 kHz repetition rate. Mass spectra of tissues were recorded from L-TOF system and then analyzed by performing a statistical approach called Principal Component Analysis (PCA). The fs-LIMS method applied is proposed as a new and pioneering technology to analyze tissues using L-TOF system, as a human free fast and reliable intra-operative cancer diagnosis method for guiding surgeon to clean the edges of cancerous tissues to be applied during the surgical operation, for pathological examinations. Fs-LIMS provides some unique diagnosis opportunities to investigate biochemical characteristics of cancerous tissues leading to obtain sensitive, fast, and reliable results. The analysis of tissue is based on distribution of molecular ion (m/z) peaks in low mass region (<m/z 100) in mass spectra. Fs-LIMS provides a great data for identification of tissues (healthy and cancerous) in details. The effect of laser pulse was investigated in this study and also different types of lasers are utilized for various investigations from surgery to spectroscopy. The experimental setup mainly consists of an ultrafast (90 fs) laser system, a mass spectrometer, laser-tissue interaction/ablation chamber, data collection, and analysis system with windows based fast digital-storage oscilloscope, statistical application codes which have been developed by our group for analyses running under MATLAB software. Paraffin embedded colon tissues have been distinguished from each other with statistical approaches using fs-LIMS based data as an alternative to histological and pathological examinations. The fs-LIMS method provides a powerful novel approach to identify and analyze tissues. This promising method provides a fast and reliable (free of human mistakes) diagnosis and guidance for pathologists, surgeons, and patients during surgical operations, as well as increase the significance of mass spectrometric tissue analysis methods, especially with those capability of molecular identification of tissues. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc.

Effects of He–Ne laser and argon laser irradiation on growth, germination, and physico-biochemical characteristics of wheat seeds (Triticumaestivum L.)

Wheat seeds (Triticumaestivum L.) were exposed to two different types of lasers, a He–Ne laser (633 nm) and an argon laser (514.5 nm), to study their effects on growth, germination, and physiological and biochemical characteristics such as the amounts of chlorophyll a, chlorophyll b, and carotenoids. A significant increase in the growth characteristics was monitored and studied keeping in view the length as well as fresh and dry weight of shoots and roots. Similarly, plant pigment contents such as chlorophyll a, chlorophyll b, and carotenoids were significantly changed. These significant alterations led to an increase in growth and germination compared with unexposed (control) wheat seeds. The experimental results of this in vitro study clearly demonstrate that different lasers like He–Ne laser and argon laser at low power significantly enhance the growth and germination of wheat seeds (Triticumaestivum L.) by positively influencing its physiological and biochemical characteristics.

Does laser therapy improve the wound healing process after tooth extraction? A systematic review.

Laser therapy could amplify the oral wound healing process by stimulating cell regeneration after injury, attenuating pain, and modulating the immune system. The purpose of this systematic review was to evaluate whether the application of laser therapy improved alveolar healing after tooth extractions. Eight electronic databases were screened: MedLine (PubMed), The Cochrane Library, Web of Science, Scopus, Lilacs, Ibecs, Scielo, and BBO. Three reviewers independently assessed the title and abstracts of potentially relevant studies. Only clinical trials and animal experiments that evaluated the wound healing effect of laser therapy after tooth extraction were included. A total of 16 studies fulfilled all criteria, thus 8 animal experiments and 8 clinical trials were included. Different types of laser were evaluated, such as CO2 , GaAlAs, Nd:YAG, Diode Laser, HeNe, and High-frequency Pulsed Diode Laser. Although HF, Diode and GaAs lasers were able to enhance wound healing process in clinical studies, four trials and one animal experiment showed no improvement in wound healing with laser therapy after tooth extractions. In general, the current available evidence in the literature showed that laser therapy improved the wound healing process, but these findings were limited to the type of laser applied and its specific settings. Further well-designed and randomized controlled trials are needed to support a benefit effect of using laser therapy after tooth extraction. PROSPERO registration number: CRD42014007509 (2014).

Unique laser coding technology to fight falsified medicines

Based on WHO statistics, counterfeit medicines represent 10% of the global drug trade. According to Directive 2011/62/EU as regards the prevention of falsified medicines from entering into the legal supply chain, a unique identification should be put on each box of drugs to be able to track and trace them. The objective of this study is to develop a technology to mark an individual traceability code directly on the surface of the tablet. By using this technique, anyone with a camera-enabled phone and a suitable application installed should be able to authenticate these drugs. By marking the medicine's surface, patients could be protected from fake drugs.The aim of the present work was to study how different types of lasers affect the film coating of the tablet during the laser marking intervention.To sum up, the present findings may contribute to efficient and reliable laser marking solutions in the unique identification procedure. Based on our measurement results, it can be stated that the excimer UV laser is clearly the most suitable marking instrument for anti-counterfeiting coding on solid coated tablet form as this caused the least amount of chemical degradation of the polymer film.

Er:YAG Laser for Metal and Ceramic Bracket Debonding: An In Vitro Study on Intrapulpal Temperature, SEM, and EDS Analysis.

To evaluate the effects of bracket removal using an erbium laser on the pulp temperature and enamel surface. Removal of orthodontic brackets with conventional debonding pliers may result in enamel cracks. To avoid damage to the enamel surface and effectively remove metal or ceramic brackets, different types of lasers, such as Nd:YAG, CO2, TM:YAP, diode laser, or Er:YAG, have been introduced for debonding. A total of 55 brackets (n = 55; 20 metal and 35 ceramic ones) were bonded to 55 caries-free premolars extracted for orthodontic indications. Brackets were irradiated with Er:YAG laser (Morita, Irvine, CA) with a wavelength of 2940 nm at a power of 3.4 W, energy 170 mJ, frequency 20 Hz, pulse duration 300 μs, tip diameter 0.8 mm, air/fluid cooling 3 mL/s, and time of irradiation: 6 sec. Debonding was made by scanning (n = 15; 6 sec irradiation at distance of 2 mm from the bracket with an "S" shape movement) and circular (n = 15; 6 sec irradiation at distance of 1 mm from the bracket) motion technique in ceramic brackets or the circular motion technique in metal brackets (n = 15). The number of 10 nonirradiated teeth with ceramic (n = 5) or metal brackets (n = 5) was used as a control in SEM test and EDS analysis. The damage in tooth enamel surface and the calcium percentage were analyzed by means of scanning electron microscope (JEOL 6610LV, JEOL, Japan) and energy dispersive X-ray spectroscopy (EDS, Oxford, United Kingdom). Temperature changes in the pulp were measured by K-type thermocouple. Evaluation of the Adhesive Remnant Index (ARI) on the enamel surface of each tooth was examined after bracket debonding. The scanning method has caused significantly lower temperature increase (mean: 0.83°C) compared with circular motion technique around the ceramic brackets (mean: 1.78°C; p = 0.0001) or the metal brackets (mean: 1.29°C; p = 0.015). ARI score showed no differences between the study groups (p = 0.57). SEM analysis revealed no cracks on enamel surface after laser-assisted debonding in comparison with the control samples where cracks were found. EDS showed a higher mean percentage of the calcium (30.7-85.8%) for all test groups compared with control samples (mean: 7%; p = 0.0002). The amount of the calcium elements was higher for metal brackets in comparison with ceramic ones (p = 0.0002). Er:YAG laser-assisted debonding causes a minor increase in the pulp temperature and reduced the risk of enamel damage compared with conventional bracket removal.

Measure of Backscatter for small particles of atmosphere by lasers

It developed a program for the atmosphere to study the backscattering for contents gas and molecules, aerosol, fog, clouds and rain droplets. By using Rayleigh, Mie and geometric scattering. The aim of research, using different types of lasers from various optical region, is to calculate differential cross scatter section and backscatter of atmosphere component in one layer from height 10-2000m. 180° is backscattering angle using ISA standard sea level condition P=1013.25 (kpa) at t0=15 ° C.and then calculated the density of molecules and water vapor molecules represented D in kg/m3. Results reflected index consist of the large value of the real part and imaginary m=1.463-0.028i.this research diff. scatter cross section of different component of atmosphere layer decreased vs. wavelengths. The purpose of lider research to find backscatter from UV to IR laser within the optical range in the atmosphere and measurement of excitation and analysis of backscatter signals. Recently, the atmosphere of Iraq has become full of dust and pollution, so by knowing the differential cross scatter section and backscatter of atmosphere. Relation between total Rayleigh scatter coefficient & type of particles include fog and clouds, aerosols and water droplets (-0.01, 0.025,- 0.005) m-1/sr-1.

Rapid identification of macro nutrients in pharmaceutical medicine using laser-induced plasma spectroscopy

Identification of macro nutrients in medicine is really necessary for healthy purpose. In this study, identification of macro elements in pharmaceutical products was carried out by laser-induced plasma spectroscopy (LIPS). A comparative study was made by employing different types of laser, namely an Nd:YAG laser and a pulse TEA CO2 laser. Experimentally, the laser beam was directed and focused by a convex lens on a mineral supplement tablet. A luminous plasma was induced on the tablet’s surface. Sharp and high-intensity emission spectra of macro elements including Ca and Mg were detected both in LIBS using Nd:YAG and pulse CO2 lasers. However, the intensities of Ca and Mg spectra are much higher for the LIBS using CO2 laser. Based on the analysis, the plasma temperature plays important role in the spectra. Namely, the plasma induced by a TEA CO2 laser is much higher than that of Nd:YAG laser; the plasma temperature for the case of TEA CO2 laser and Nd:YAG laser were 6400 K and 4500 K, respectively.

Cyclodestructive procedures for non-refractory glaucoma.

Cyclodestructive procedures for non-refractory glaucoma.

Dört Kavite Dezenfektan Solüsyonunun Ve İki Farklı Lazer Sisteminin Dentin Adezivlerin Mikro Makaslama Bağlanma Dayanımı Üzerine Etkinliği

Objective: The aim of this study, was to investigate the efficacy of four cavity disinfectant solutions and two different types of laser on the micro-shear bond strength of dentin adhesives as in-vitro. Methods: Seventy permanent human molar teeth were sectioned parallel to the occlusal surface to expose dentin in the midcoronal. The specimens were randomly divided into seven main groups (n=10) Then cavity disinfection procedures were applied; Saline(Control); Sodium Hypochlorite (NaOCl); Chlorhexidine Gluconate (CHX); Super-oxidized water (SPO); Aqueous ozone (AO); KTP laser; Er:YAG laser. Then the main groups were randomly divided into two subgroups as self-etch (Clearfil S3 Bond Plus) and etch-and-rinse (Bisco All-Bond Universal) adhesive systems. Four cylinders of composite resin were applied to each bonded dentin surface using a tygon tube. The specimens were tested with universal testing machine. The results were analyzed by two-way ANOVA and Tukey’s tests. Results: Statistical comparisons of the groups could be listed respectively from lowest to highest as; self-etch adhesive system, CHX&amp;lt;Control,AO,SPO&amp;lt;KTP&amp;lt;NaOCl&amp;lt;Er:YAG (p&amp;lt;0.05); etch-and-rinse adhesive system, CHX&amp;lt;Control=AO=SPO&amp;lt;KTP&amp;lt;Er:YAG&amp;lt;NaOCl (p&amp;lt;0.05). When adhesive systems were compared with each other; there were found statistically significant differences within NaOCl groups, KTP laser groups and Er:YAG laser groups. Conclusions: Er:YAG and KTP laser systems may increase the bond strength of both adhesive systems compared to CHX, SPO and AO. Therefore, both of laser systems may advisable for cavity disinfection in restorative dentistry.

Different lasers and techniques for proliferative diabetic retinopathy.

Different lasers and techniques for proliferative diabetic retinopathy.

Técnicas quirúrgicas y láser en cicatrices atróficas de acné

Las cicatrices de acné, especialmente las de tipo atrófico, constituyen una complicación frecuente del acné vulgar que se asocia a un importante impacto psicológico. Múltiples terapias se han utilizado para mejorar su aspecto, sin embargo, ninguna ha demostrado ser completamente eficaz y segura. El tratamiento quirúrgico en acné cicatricial incluye técnicas como escisión elíptica, escisión o elevación por punch, subcisión y distintos tipos de láser. El objetivo de esta revisión es presentar la evidencia disponible respecto a las técnicas quirúrgicas y dispositivos láser utilizados en cicatrices atróficas de acné.

An Assessment of knowledge, Attitude and Practice of Lasers among periodontists in India

In the history of science, the invention of laser has attracted the attention of a lot of people. Maiman, in the year 1960, introduced “light amplification by stimulated emission of radiation” (LASER) making use of Einstein’s theory on stimulated emission. Laser helps to remove the microorganisms and diseased soft tissue and it also stimulates wound healing. However, the clinical value and awareness of the advantages of their use is limited. Food and drug administration have granted their approval. There are different types of lasers that are used in dentistry. Some of them being Diode, Er: YAG (Erbium: Yttrium-Aluminium-Garnet), Argon, Carbon dioxide, Nd: YAG (Neodium: Yttrium-Aluminium-Garnet). Lasers can be used in the field of periodontics for soft tissue crown lengthening procedure, depigmentation, curettage, frenectomy, operculectomy, soft tissue ablation, mechanical debridement of subgingival root surface and treatment of periodontal pockets. Lasers are also used in other fields of dentistry such as restorative and for acquiring biopsies. The present study was a questionnaire based study assessing the knowledge, attitude and practice of lasers among periodontists in India. A cross sectional study was carried out using a research based questionnaire. The questionnaire consisted of 24 questions. It was filled by 45 periodontists in India. The questions were based on assessment of knowledge, attitude and practice. The percentage of knowledge was 65.6%, attitude was 82.1% and practice was 54.5%.

Integrated Pound\u2212Drever\u2212Hall laser stabilization system in silicon

Low noise stable lasers have far-reaching applications in spectroscopy, communication, metrology and basic science. The Pound−Drever−Hall laser stabilization technique is widely used to stabilize different types of lasers in these areas. Here we report the demonstration of an integrated Pound−Drever−Hall system that can stabilize a low-cost laser to realize a compact inexpensive light source, which can ultimately impact many fields of science and engineering. We present an integrated architecture utilizing an electronically reconfigurable Mach−Zehnder interferometer as the frequency reference to reduce the frequency noise of semiconductor lasers by more than 25 dB and the relative Allan deviation by more than 12 times at 200 μs averaging time. Compared to the bench-top implementations, the integrated Pound−Drever−Hall system has significantly lower power consumption, less sensitivity to the environmental fluctuations and occupies an area of only 2.38 mm2. The photonic and electronic devices are integrated on a standard 180 nm complementary metal-oxide semiconductor silicon-on-insulator process.

Treatment of benign pigmented lesions: understanding different types of laser

Pigmented lesions are exceedingly common, appear on all parts of the body and are often requested to be treated by aesthetic patients. They can range from small discreet lesions to large, confluent areas of pigmentation. Just as their size and shape can vary, so can their location within the skin, which has a significant influence on the strategy used to treat them. It is not enough to be able to simply diagnose the lesion, it is also essential that aesthetic practitioners understand the properties of the laser they are using to treat the lesion and its method of tissue interaction. This article will briefly cover the fundamentals of laser treatment of benign pigmented lesions.