The Effect of Er:YAG Laser on a Shear Bond Strength Value of Orthodontic Brackets to Enamel—A Preliminary Study

We sought to evaluate the effects of Er:YAG laser (LightTouch, LightInstruments, Israel) conditioning on enamel roughness and shear bond strength of orthodontic brackets on enamel. Eighteen human molars (n = 9) and premolars (n = 9), were divided into 3 groups depending on the enamel conditioning method; Er:YAG laser (G1, n = 6), conventional etching with 37% orthophosphoric acid (G2, n = 6), Er:YAG laser combined with conventional etching (G3, n = 6). Er:YAG laser parameters were as follows: energy: 100 mJ, frequency: 10 Hz, exposure time: 10 s, applicator diameter: 600 μm, fluence: 35.37 J/cm², distance: 1 mm away from a tooth, cooling: 80%. An MTS 858 MiniBionix^® machine was used to determine the shear bond strength (MTS System, Eden Prairie, MN, USA). The enamel structure was assessed using X-ray microtomography (SkyScan 1172, Bruker, Kontich, Belgium). The highest values of shear bond strength were obtained in the G3 group (9.23 ± 2.38 MPa) and the lowest values in the G2 group (6.44 ± 2.11 MPa) (p < 0.05). A significant change in the enamel surface was noted after applying laser, reaching up to 9% of enamel thickness, which was not observed in the etched samples. Moreover, the Er:YAG laser-irradiated enamel surface was characterized by the greatest roughness. The combined use of an Er:YAG laser with a conventional etching improves the adhesion of composite materials to the tooth.     

Orthodontic Bracket Removal Using LASER-Technology—A Short Systematic Literature Review of the Past 30 Years

Background: Since fixed orthodontic treatment is widely spread and one of its inconveniences is bracket removal, as this affects enamel integrity as well as being a cause of discomfort to the patient, studies have searched for the most adequate bracket removal technique, many of them focusing on using laser-technology. Methods: Our review focused on articles published investigating methods of orthodontic bracket removal using laser technology in the last 30 years. Results: 19 relevant studies were taken into consideration after a thorough selection. Different types of laser devices, with specific settings and various testing conditions were tested and the investigators presented their pertinent conclusions. Conclusions: Most studies were performed using ceramic brackets and the best results in terms of prevention of enamel loss, temperature stability for the tooth as well as reduced chair time were obtained with Er:YAG lasers.     

Hydroxyapatite Film Coating by Er:YAG Pulsed Laser Deposition Method for the Repair of Enamel Defects

There are treatments available for enamel demineralization or acid erosion, but they have limitations. We aimed to manufacture a device that could directly form a hydroxyapatite (HAp) film coating on the enamel with a chairside erbium-doped yttrium aluminum garnet (Er:YAG) laser using the pulsed laser deposition (PLD) method for repairing enamel defects. We used decalcified bovine enamel specimens and compacted α-tricalcium phosphate (α-TCP) as targets of Er:YAG-PLD. With irradiation, an α-TCP coating layer was immediately deposited on the specimen surface. The morphological, mechanical, and chemical characteristics of the coatings were evaluated using scanning electron microscopy (SEM), scanning probe microscopy (SPM), X-ray diffractometry (XRD), and a micro-Vickers hardness tester. Wear resistance, cell attachment of the HAp coatings, and temperature changes during the Er:YAG-PLD procedure were also observed. SEM demonstrated that the α-TCP powder turned into microparticles by irradiation. XRD peaks revealed that the coatings were almost hydrolyzed into HAp within 2 days. Micro-Vickers hardness indicated that the hardness lost by decalcification was almost recovered by the coatings. The results suggest that the Er:YAG-PLD technique is useful for repairing enamel defects and has great potential for future clinical applications.     

Quantitation of colonic injury from argon laser, neodymium: YAG laser and monopolar electrocautery applied to flat mucosa and small sessile polyps of the canine colon

This study determined the optimum laser energy for ablation of colonic mucosal lesions and small sessile polyps in the canine colon. Neodymium (Nd):YAG laser, argon laser, and monopolar electrocautery were applied to exposed canine colonic mucosa for various application times at various power settings. At the minimum energy level necessary to ablate mucosa, the Nd:YAG laser caused greater muscularis injury than the argon laser and monopolar electrocautery. At higher energy levels, monopolar electrocautery and Nd:YAG laser caused greater muscularis injury than argon laser. Small surgically created polyps in the canine colon were ablated endoscopically with the three energy sources. Single-session complete polyp ablation occurred most frequently with Nd:YAG laser and least frequently with argon laser. The depth of tissue injury beneath polyp ablation sites was least with argon laser and greatest with Nd:YAG laser. This study suggests that the argon laser is safer than the Nd:YAG laser or monopolar electrocautery for coagulation of flat colonic mucosal lesions. Although the argon laser is safer for the coagulation of small sessile colonic polyps, it may be less effective than monopolar electrocautery or the Nd:YAG laser for the single-session fulguration of polyps greater than 5 mm in diameter.     

Use of the thermal laser effect of laser irradiation for cardiovascular applications exemplified by the Nd:YAG laser

Techniques of percutaneous transluminal application of laser energy for vessel recanalization have been used clinically since 1983. The commonly used Nd:YAG and argon lasers achieve ablation of atherosclerotic plaques by thermal action (vaporization). In order to reduce undesirable thermal damage in the neighborhood of the target tissue and to avoid vessel perforation, optimal irradiation parameters, modified (atraumatic) fiber tips (hot tips, sapphires), and steerable catheter systems needed to be implemented. Favorable results from peripheral application have encouraged use in the coronary circulation. More recently, coagulative tissue effects of circumferential irradiation of the vessel wall during balloon dilatation have been used for stabilization of acute and late results after mechanical balloon angioplasty. Enhancement of the differential light absorption of atherosclerotic plaque by use of biological dyes may further improve selective intravascular laser application. Intraoperative ECG-guided laser coagulation of arrhythmogenic areas of myocardium is a method for treatment of malignant arrhythmias. Transluminal non-operative application of myocardial laser photocoagulation has now been tested experimentally and shown to be safe and effective. There was no arrhythmogenicity or thermal damage of coronary arteries associated with this method. Innovative techniques such as nanosecond pulsed excimer lasers (athermal action) and development of "intelligent" lasers--which are equipped with spectroscopy-guided feedback systems for plaque recognition--have opened new perspectives and will further improve safety and efficacy of clinical laser application. However, according to current experience, the thermally acting Nd:YAG laser is an effective and versatile mode of laser therapy for selected cardiovascular indications.     

The Effect of Er:YAG Lasers on the Reduction of Aerosol Formation for Dental Workers

Infection prevention in dental practice plays a major role, especially during the COVID-19 pandemic. This study aimed to measure the quantity of aerosol released during various dental procedures (caries and prosthetic treatment, debonding of orthodontic brackets, root canal irrigation) while employing the Er:YAG lasers combined with a high-volume evacuator, HVE or salivary ejector, SE. The mandibular second premolar was extracted due to standard orthodontic therapy and placed in a dental manikin, to simulate typical treatment conditions. The particle counter was used to measure the aerosol particles (0.3–10.0 μm) at three different sites: dental manikin and operator’s and assistant’s mouth area. The study results showed that caries’ treatment and dental crown removal with a high-speed handpiece and the use of the SE generated the highest aerosol quantity at each measured site. All three tested Er:YAG lasers significantly reduced the number of aerosol particles during caries’ treatment and ceramic crown debonding compared the conventional handpieces, p < 0.05. Furthermore, the Er:YAG lasers generated less aerosol during orthodontic bracket debonding and root canal irrigation in contrast to the initial aerosol quantity measured in the dental office. The use of the Er:YAG lasers during dental treatments significantly generates less aerosol in the dental office setting, which reduces the risk of transmission of viruses or bacteria.     

Palliative laser therapy for tumours of the gastrointestinal tract.

The argon ion and Nd: YAG lasers were used initially in the mid 1970s to produce haemostasis in acutely bleeding peptic ulcers. With the evolution of treatment techniques, the main area of use of the Nd: YAG laser has now become the palliation of upper and lower GI malignancies. Thermal ablation of tumours may be achieved endoscopically by non-contact laser application at high power, or in the contact mode using artificial sapphire probes at much lower energy levels. Still lower powers can be employed therapeutically using interstitial hyperthermia, and this is best applied endoscopically to exophytic tumour nodules in the gut lumen or to tumours localized ultrasonically in solid organs, such as the liver or pancreas. PDT involves destruction of previously photosensitized tumours by the cytotoxic action of singlet oxygen released on exposure of the neoplastic tissue to light of an appropriate wavelength. Although the theory is attractive, the available experimental and clinical information suggests that treatment should, for the present, be confined to small or early malignancies whose depth of invasion can be verified by endoscopic ultrasound or other imaging techniques. PDT carries the biological advantage of healing by regeneration with preservation of connective tissue stroma, while the Nd: YAG laser causes destruction by thermal coagulation or vaporization and subsequent healing by fibrosis. Laser therapy of GI tumours expands the range of therapeutic endoscopic procedures in a relatively safe and readily repeatable manner which achieves high patient tolerance. By reducing morbidity, mortality and time spent in hospital, it offers significant advantages in the palliative treatment of conditions previously managed by conventional surgery, and also offers opportunities for treatment of previously inoperable disorders. Developments in laser technology and diagnostic imaging techniques are likely to promote laser therapy in the future as a primary treatment modality.     

Laser tissue interaction in direct myocardial revascularization.

This investigation examines the various laser choices used for transmyocardial laser revascularization (TMLR) with emphasis on the laser-tissue interaction. A series of in vivo (porcine model, n=27) and in vitro experiments were performed to study the effects of CO(2), holmium:YAG, and XeCl excimer lasers on the histological outcome of TMR channels. Computerized histopathological analysis has revealed that the CO(2) and holmium:YAG lasers produce substantial unpredictable thermal damage and differ predominantly in the amount of the mechanical injury or tissue shredding. In comparison, the excimer laser appears to produce the most uniform tissue ablation with the least thermal and shockwave damage.     

SEM Evaluation of Tooth Surface after a Composite Filling Removal Using Er:YAG Laser,Drills with and without Curettes,and Optional EDTA or NaOCl Conditioning

(1) Background: This study aimed to evaluate the microporosity of the tooth surface structure adjacent to the cemento-enamel junction (CEJ) after the removal of composite fillings with a drill in comparison with removal by an Er:YAG laser and after cleaning with a periodontal curette, chemical EDTA and NaOCl (sodium hypochlorite) conditioning. (2) Methods: The research material consisted of 30 extracted premolars with cervical composite fillings. The teeth were divided into six groups according to the method of tooth preparation: group G1 (n = 5)—a diamond drill; group G2 (n = 5)—a diamond drill + curette; group G3 (n = 5)—a diamond drill + 24% EDTA (PrefGel, Straumann, Switzerland); group G4 (n = 5)—an Er:YAG laser (LightWalker, Fotona, Ljubljana, Slovenia) set with the following parameters: power: 1.65 W (composite removal, CR), 1.2 (tooth conditioning, TC), energy: 110 mJ (CR), 80 mJ (TC), frequency: 15 Hz, pulse duration: 50 μs, tip diameter: 1 mm, air/fluid cooling: 4, distance 1.5 mm, energy density: 14.01 J/cm² (CR), 10.19 J/cm² (TC); group G5 (n = 5)—an Er:YAG laser + 2% sodium hypochlorite (NaOCl); group G6 (n = 5)—an Er:YAG laser + 5.25% NaOCl. In each tooth, three cavities were made and subjected to analysis. The dentin surface was evaluated using a scanning electron microscope (SEM). (3) Results: Groups G1 and G2 exhibited mechanical damage to the tooth surface structure caused by the rotary motion of a diamond drill. The SEM image showed a smear layer that could only be removed chemically using 24% EDTA gel (group G3). The tooth surfaces prepared with the Er:YAG laser (groups G4–G6) revealed a homogeneous structure without damage along with open dentinal tubules (without smear layer) and visible denaturation of collagen fibers. The sodium hypochlorite (NaOCl) conditioning did not increase the visibility of dentinal tubules. (4) Conclusions: Dentin surfaces have open dentinal tubules after removal of the composite filling using the Er:YAG laser and therefore do not require additional NaOCl conditioning.     

Pulsed laser and thermal ablation of atherosclerotic plaque: morphometrically defined surface thrombogenicity in studies using an annular perfusion chamber.

Although clinical trials using laser and thermal angioplasty devices have been underway, the effects of pulsed laser and thermal ablation of atherosclerotic plaque on surface thrombogenicity are poorly understood. This study examined the changes in platelet adherence and thrombus formation on freshly harvested atherosclerotic aorta segments from Watanabe-heritable hyperlipidemic rabbits after ablation by two pulsed laser sources (308-nm xenon chloride excimer and 2,940-nm erbium:yttrium-aluminum-garnet [YAG] lasers) and a prototype catalytic hot-tip catheter. Specimens were placed in a modified Baumgartner annular chamber and perfused with citrated whole human blood, followed by quantitative morphometric analysis to determine the percent surface coverage by adherent platelets and thrombi in the treated and contiguous control areas. Pulsed excimer laser ablation of plaque did not change platelet adherence or thrombus formation in the treated versus control zones. However, photothermal plaque ablation with a pulsed erbium:YAG laser resulted in a 67% reduction in platelet adherence, compared with levels in control areas (from 16.7 +/- 2.2% to 5.5 +/- 1.8%; p less than 0.005). Similarly, after plaque ablation using a catalytic thermal angioplasty device, there was a 74% reduction in platelet adherence (from 29.2 +/- 5.1% to 7.7 +/- 1.6%; p less than 0.005) and a virtual absence of platelet thrombi (from 8.6 +/- 2.3% to 0.03 +/- 0.03%; p less than 0.005). This reduced surface thrombogenicity after plaque ablation with either an erbium:YAG laser or a catalytic hot-tip catheter suggests that thermal modifications in the arterial surface ultrastructure or thermal denaturation of surface proteins, or both, may be responsible for reduced platelet adherence. These in vitro findings indicate that controlled thermal plaque ablation by catheter-based techniques may elicit endovascular responses that can reduce early thrombus formation during angioplasty procedures.     

Current Status of Lasers for Arrhythmia Ablation

Current Status of Lasers for Arrhythmia Ablation. Wavelength specific effects and mode of laser operation allow either photocoagulation or tissue removal as a means of approaching arrhythmia ablation. Successful intraoperative ablation of ventricular tachycardias has been performed with the Nd: YAG laser (photocoagulation) and argon laser (tissue vaporization). The argon laser has been used intraoperatively for transection of accessory pathways. Experimental studies indicate a strong theoretical potential for Nd:YAG laser catheter ablation of ventricular tachycardia. Laser energy has been used experimentally to evaluate the possibility of AV junctional ablation/modification and accessory pathway ablation. Adaption of laser energy to effective catheter systems for arrhythmia ablation requires solutions to problems inherent in all catheter systems and some unique to laser energy. (J Cardiovasc Electrophysiol, Vol. 3, pp. 345–353, August 1992)     

Physics of surgery with lasers

The characteristics of the principal lasers used in surgery are summarized in Table 1. Their diverse effects on biologic tissues permit the following generalizations: The CO2 laser is best suited for precise, visually controllable tissue removal by vaporization with minimal marginal damage. Hemostasis is excellent for bleeding from capillary vessels, but difficult for larger ones. The Nd:YAG laser is best suited for the coagulation of larger tissue volumes of the order of 10 mm3 or more. Tissue heating inherently extends for several millimeters, leading to excellent hemostasis. Radiation from this laser is well transmitted through flexible optical fibers and clear fluids. The argon ion laser emits radiation in the visible range and is ideally suited for treating the retina and other tissues in the eye without damage to its transparent structures. Radiation of this laser is strongly absorbed by pigmented tissues, scattered and reflected by others, and transmitted by fluids. Its radiation can be focused to very small spot sizes, leading to high precision and high-power densities. It has hemostatic properties intermediate between those of the CO2 and of the Nd:YAG laser radiations. It is well transmitted through optical fibers and clear fluids. It is used extensively in ophthalmology and dermatology. Selected applications to neurosurgery and otology are being investigated. These lasers have become indispensable adjuncts to the surgical armamentarium of several specialties. The very success of these lasers is leading to a critical examination of their shortcomings and to a search for improved systems. Examples are (1) the ongoing search for optical fibers to transmit the radiation of the CO2 laser; (2) the development of systems for the sequential delivery to tissues of several wavelengths from a single unit (Fig. 14); and (3) investigations of tissue effects of laser beams in the ultraviolet and in the infrared at wavelengths intermediate between those of the Nd:YAG and CO2 lasers. The use of lasers has already contributed to improved medical care in many surgical disciplines. Additional areas of application can be confidently anticipated.     

Thermal Evaluation by Infrared Thermography Measurement of Osteotomies Performed with Er:YAG Laser,Piezosurgery and Surgical Drill—An Animal Study

The bone healing process following osteotomy may vary according to the type of surgical instrumentation. The aim of the present in vivo study was to determine thermal changes of the bone tissue following osteotomies performed by Er:YAG laser ablation in contact and non-contact modes, piezoelectric surgery, and surgical drill using an infrared thermographic camera. For each measurement, the temperature before the osteotomy-baseline (Tbase) and the maximal temperature measured during osteotomy (Tmax) were determined. Mean temperature (ΔT) values were calculated for each osteotomy technique. The significance of the difference of the registered temperature between groups was assessed by the ANOVA test for repeated measures. Mean baseline temperature (Tbase) was 27.9 ± 0.3 °C for contact Er:YAG laser, 29.9 ± 0.3 °C for non-contact Er:YAG laser, 29.4 ± 0.3 °C for piezosurgery, and 28.3 ± 0.3 °C for surgical drill. Mean maximum temperature (Tmax) was 29.9 ± 0.5 °C (ΔT = 1.9 ± 0.3 °C) for contact Er:YAG laser, 79.1 ± 4.6 °C (ΔT = 49.1 ± 4.4 °C) for non-contact Er:YAG laser, 29.1 ± 0.2 °C (ΔT = −0.2 ± 0.3 °C) for piezosurgery, and 27.3 ± 0.4 °C (ΔT = −0.9 ± 0.4 °C) for surgical drill. Statistically significant temperature changes were observed for the non-contact laser. The results of the study showed beneficial effects of the osteotomy performed by the Er:YAG laser used in the contact mode of working as well as for piezosurgery, reducing the potential overheating of the bone tissue as determined by means of infrared thermography.     

Angioplasty of coronary arteries by laser radiation in 1988

The ability of laser radiation to destroy healthy or pathologic vascular tissue in vitro and in vivo marked the beginning of therapeutic ablation of atheromatous deposits in man. The problems encountered by application of this procedure to treatment of coronary heart disease are very complex, and experience acquired using lasers for peripheral vascular disease is of not much help in this area. It is clear that continuous emission lasers (YAG, Argon, CO2), which produce coagulation necrosis, thrombosis, and vasospasm must be ruled out in favor of impulse type lasers (CO2TEA, YAG Q-S, pumped lasers with dye and exciplex lasers) if the latter can provide a critical thermal relaxation time. Currently, exciplex lasers are a possible method whose potential efficacy and safety gave been demonstrated with certainty in coronary angioplasty. Indeed, although their mechanism of action is poorly understood, they offer the twofold advantage of being able to focus on a volumetrically defined ablation, and to leave the surrounding tissue intact. The clinical application of these tools remains to be developed. Laser angioplasty requires in situ diagnostic methods based on the optical utilization of intrinsic and extrinsic chromophores, the objective of intensive research. Its relative role in comparison to other methods of ablation, and specific indications remain to be defined.     

Transmyocardial laser revascularization

Opinion statement Transmyocardial laser revascularization (TMR) has been performed on over 12,000 patients worldwide. Since 1990, the treatment has provided significant angina relief for symptomatic end-stage coronary disease that is refractory to medical therapy. Seventy-five percent of patients treated with TMR have demonstrated a decrease of two or more angina classes postoperatively. As a result, TMR has provided a significant improvement in quality of life for patients, resulting in fewer hospital admissions and decreased dependency on medications. Two different wavelengths of light, carbon dioxide (CO₂) and holmium yttrium-aluminum-garnet (Ho:YAG), have been employed. Results obtained using these lasers differ. The CO₂ laser has demonstrated a perfusion benefit as well as long-term improvement in quality of life and angina relief. The Ho:YAG laser has not demonstrated these results. These differences may, in part, explain the failure of percutaneous myocardial laser revascularization. This catheterbased approach was not as successful as TMR due to its partial thickness treatment of the myocardium as well as its use of the Ho:YAG laser. In addition to the patients with end-stage coronary disease who undergo TMR as sole therapy, there are an increasing number of patients who have been treated with a combination of coronary artery bypass grafting and TMR. This provides a more complete revascularization than leaving territories ungrafted. Further enhancement of the angiogenic response seen after TMR may be seen by the addition of gene therapy to TMR treatment.     

Comparison of Silane Heat Treatment by Laser and Various Surface Treatments on Microtensile Bond Strength of Composite Resin/Lithium Disilicate

In the current study, we evaluated the effects of heat treatment (by Er:YAG or furnace) and various surface treatments on the microtensile bond strength (μTBS) of silanized lithium disilicate ceramic. Seventy lithium disilicate (IPS e. max Press; Ivoclar Vivadent) and composite resin (Tetric N-Ceram; Ivoclar Vivadent) blocks were made and distributed into seven groups (n = 10) at random: S: silanization alone; ALS: airborne particle abrasion (APA) and silanization; SC: APA modified with silica and silanization; SHT1: silanization and heat treatment by Er:YAG; SHT2: silanization and heat treatment performed in the furnace (100 °C, 1 min); HF: etching with HF; and HFS: etching with HF and silanization. Every ceramic specimen was cemented to a composite resin block after surface treatment. Cemented specimens were embedded into acrylic resin and were tested with the μTBS test. Data were analyzed using one-way ANOVA and Tamhane T2 tests (α = 0.05). The SHT1 group had the highest bond of strength compared to the other groups (27.46 MPa). The ALS group had the lowest strength of the groups (15.56 MPa). Between SHT2 and HFS (p = 1), the comparison of the mean µTBS values showed no significant differences. It was concluded that silane heat treatment increased the resin composite–ceramic bond strength; however, within the terms of μTBS, the Er:YAG laser treatment was more successful than other surface treatment applications.     

Thermal Effects In Vivo from Holmium: YAG Lasing in the Intracoronary Setting

While the thermal effect of laser energy does ablate atheromatous plaque, thermal injury to adjacent tissue produces high rates of arterial thrombosis and spasm. Holmium:YAG lasers use a pulsed laser source to maximize photoblative effects while minimizing thermal effects. These lasers have been utilized clinically to ablate thousands of complex coronary lesions with low rates of spasm and thrombosis, suggesting that little or no thermal injury occurs with these devices. However, we have been able to detect thermal injury in patients angioscopically in coronary arteries after holmium:YAG lasing. Here we report the use of directional coronary atherectomy (DCA) to òbiopsyó arteries in patients following holmium:YAG laser treatment, allowing direct histologic examination of lased tissue. Thirty such lased DCA samples were matched for patient age, gender, target vessel, and lesion characteristics with thirty control DCA samples obtained from patients undergoing DCA without prior lasing. Blinded pathologic examination correctly identified 27/30 control samples but only 18/30 lased samples. Subsequent unblinded analysis, sometimes with recutting and restaining of tissue blocks, resulted in the detection of thermal effects in 27/30 lased samples. The thermal effects seen included edge disruption, charring, coagulation necrosis, and most commonly, vacuolization. We conclude that holmium:YAG lasing does produce detectable thermal effects in tissue in most patients. These effects can be quite subtle or can be extensive, but do not predict poor patient outcome.     

Do thermal lasers increase the risk of distal embolism in angioplasties? An experimental study with cw Nd: YAG and excimer lasers.

A thermal (contact cw Nd:YAG) and non-thermal (Xe-Cl excimer) laser were used to irradiate fresh human blood in an experimental setting to investigate the possible thrombogenic properties of lasers and to compare the two laser modalities. Blood was obtained into 10 ml citrate test tubes from healthy volunteers. Laser irradiations were performed with cw Nd: YAG laser (10W, 3 and 6 secs) and with excimer laser (20 mJ, 60 ns pulses, 15 secs). Altogether, 80 samples were collected. A thromboelastographic (TEG) analysis was performed for each sample as well as the controls, which were taken simultaneously. Serum potassium levels indicating haemolysis were also determined. Thermal laser energy seems to have more thrombogenic effect than excimer laser. There appear to be no previous reports available in the literature using TEG to determine thrombogenicity of different lasers.     

The Effectiveness of Lasers in Treatment of Oral Mucocele in Pediatric Patients: A Systematic Review

The mucocele is the most common minor salivary gland associated disease of the oral cavity. It is also considered one of the most common biopsied oral lesions in pediatric patients. In recent years, extensive evidence has been published about the usage of lasers in treating mucoceles in pediatric patients. The aim of the present study was to assess the effectiveness of laser irradiation in the treatment of pediatric mucocele. An electronic search of databases (PubMed, Scopus, Web of Science and Google Scholar) was carried out in order to identify all relevant articles using a combination of the following keywords: “Pediatric”, “Oral”, “Mucocele”, “Dental”, “Oral Medicine”, “Soft Dental Lasers”, “Hard Dental Lasers”, and “Lasers,” for all case reports, case series, case-control and cohort studies published from 2007 to 2021. After limiting the search results, removing duplicate titles, and eligibility evaluation, 17 papers were enrolled in the study. Out of the total studies included, 10 articles were related to the diode (635 nm, 808 nm, 810 nm, and 980 nm), 5 to CO₂ (10,600 nm), 3 to Er, Cr: YSGG (2780 nm), and 1 involving KTP lasers (532 nm). All studies indicated successful clinical results on mucocele excision with better intra- and post-operative indicators. The general characteristics and outcomes were summarized, and the quality of the studies was assessed using CARE guidelines in this systematic review. The reduction or absence of pain and bleeding, hemostasis, reduced operating time, minimal analgesic consumption, and an antibacterial effect were among the advantages of laser irradiation in the included studies. The laser has proven itself to play an effective role in the treatment of oral mucocele in paediatric patients.     

The development of laser angioplasty

Recent developments in technology have stimulated interest in the use of catheter-directed laser energy for removal of atherosclerotic plaques. Over the past three years, intensive research efforts by a number of investigators have defined the potential therapeutic benefit of laser angioplasty, as well as its limitations. Unlike balloon angioplasty, the laser has the capacity to remove totally atheromatous plaque or thrombus by photovaporization. Unique properties of the laser allow light energy to be concentrated for plaque removal. Arterial damage adjacent to the plaque is prevented by certain lasers, while others produce thermal injury to the arterial wall. Chemical pretreatment with vital dyes or drugs has been shown to enhance absorption of laser radiation by plaque and may enable selective destruction of the arterial plaque. Fiberoptic catheters have been designed to transmit laser energy to remote intravascular targets; however, precise guidance systems for catheter delivery have not been developed sufficiently for safe intracoronary application. Complete arterial healing by endothelial cell migration has been demonstrated after laser ablation of plaque in animal studies. Among the first four clinical trials of laser angioplasty, relief of atherosclerotic obstruction was successful using argon, neodymium-YAG, and carbon dioxide lasers. Despite the satisfactory initial appearance of laser-treated arteries, the long-term effects and risk of atherogenesis are undetermined. A potential risk of thrombosis has been identified after laser application, especially with the argon and NdYAG lasers. Further basic and clinical research are needed to establish the role of this promising new technology in the treatment of cardiovascular disease.