宫腔镜下Nd:YAG激光治疗子宫内疾病78例分析

目的 :评价宫腔镜对子宫内疾病的诊断价值和采用Nd :YAG激光治疗子宫内疾病的效果。方法 :对 78例子宫内疾病 (包括子宫内粘连、子宫粘膜下肌瘤、子宫纵隔、子宫粘膜息肉、宫颈息肉及宫颈管囊肿 )采用宫腔镜进行诊断 ,并用Nd :YAG激光进行治疗。结果 :宫腔镜诊断子宫内疾病的准确率高于超声诊断及放射诊断。采用Nd :YAG激光治疗的一次性成功率为 97.43 %。手术时间为 2 0 5 5分钟 ,平均 3 5 .7± 18.5分钟。无明显并发症。术后 1 3个月随访 2例病人有残留的粘连带及纵隔组织而进行二次手术。其余患者均恢复正常。 8例患者 (有生育要求者 )在一年内妊娠。结论 :对于子宫内疾病宫腔镜有较高的临床价值 ,采用Nd :YAG激光治疗具有更简便、安全、疗效确切等优点 ,具有广泛的应用前景     

Effect of Nd: YAG laser on titanium dental implants studied by AFM

Bacterial contamination of dental implants is considered the main cause of implant failure. Recently, the laser treatment of the implant surface has been proposed as an useful method for decontamination. In such a view, the present study was conducted to investigate the effects of a Nd:YAG laser on the surface morphology of a titanium dental implant by means of an atomic force microscope. We demonstrated that, when the pulse energy of the laser was kept below 30 mJ, independently from the pulse rate, the laser-treated specimens exhibited a qualitatively similar surface morphology when compared to the untreated titanium implants, suggesting that the implant surface was unaffected by the treatment, in these particular conditions. We also found that, by cooling the implant surface with an air flow? during laser irradiation, the mean temperature of the implant was maintained under 37 degrees C. All these data taken together suggest the possibility to use Nd:YAG laser for the treatment of failing dental implants.     

Characterization of calcium phosphate coatings deposited by Nd:YAG laser ablation at 355 nm: influence of thickness

Calcium phosphate coatings were deposited by pulsed laser ablation with a radiation of 355 nm from a Nd:YAG laser. All the coatings were obtained at the same conditions, but deposition was stopped after different number of pulses to get coatings with different thickness. The influence of thickness in the structural and mechanical properties of the coatings was investigated. Coatings structure was characterised by scanning electron microscopy, grazing incidence X-ray diffractometry and Raman spectroscopy. The mechanical properties were evaluated by scratch test. The morphology of the coatings is dominated by the presence of droplets. The coatings are composed mainly of hydroxyapatite, alpha tricalcium phosphate and amorphous calcium phosphate. Thinner coatings withstand higher loads of failure in the scratch test.     

激光泪道成形术治疗泪道阻塞的临床观察

目的 观察激光泪道成形术治疗泪道阻塞的效果及复发病例再次激光联合插管治疗的效果。方法 采用Nd：YAG激光泪道成形术治疗泪道阻塞102例。132眼。对复发病例。再次行激光联合插管治疗。结果 113眼一次治愈，有效9眼。术后10眼复发，再次行激光联合插管治疗，7眼治愈，3眼未愈。本组总治愈率90．9％，有效率97．7％。结论 Nd：YAG激光泪道成形术治疗泪道阻塞操作简单，安全有效，复发病例联合插管治疗可以提高治愈率。     

Q开关Nd：YAG激光联合左旋维生素C离子导入治疗黄褐斑的临床观察

目的：探讨Q开关Nd：YAG激光联合左旋维生素C离子导入治疗黄褐斑的临床疗效和安全性,为黄褐斑的治疗提供疗效确切并安全的治疗方法。方法：将90例黄褐斑的患者随机分为3组,每组30例。治疗组给予Q开关Nd：YAG激光联合左旋维生素C离子导入治疗;对照1组单纯给予Q开关Nd：YAG激光治疗;对照2组单纯给予左旋维生素C离子导入治疗。激光治疗每两周1次,左旋维生素C离子导入每周1次,共治疗16周。分别在治疗8周后和16周后通过MSAI评分进行疗效分析,并在治疗结束后以水疱、座疮以及色素沉着和色素减退来进行不良反应分析。结果：在治疗8周后,联合治疗组与对照1组疗效差异无统计学意义（尸〉0．05）,与对照2组疗效差异有统计学意义（P＜O．05）;16周时治疗组有效率为73．33％,对照1组为73．33％,对照2组为36．67％,差异有统计学意义（P均〈O．05）;治疗组不良反应发生率为20．00％,对照l组为33．33％,对照2组为3．33％,差异无统计学意义（P〉0．05）结论：治疗8周后,Q开关Nd：YAG激光联合左旋维生素C离子导人治疗的方法疗效并不优于单纯激光治疗,但优于单纯左旋维生素C离子导人的方法;治疗16周后,Q开关Nd：YAG激光联合左旋维生素C离子导入治疗黄褐斑比两者单独应用效果好;安全性有保障,值得临床推广。     

强脉冲光联合Nd:YAG激光治疗黄褐斑疗效观察

目的:探讨强脉冲光联合Nd:YAG激光治疗黄褐斑的疗效。方法:60例患者按治疗方法不同分成3组:强脉冲光组、Nd:YAG激光组、联合组（强脉冲光联合Nd:YAG激光组）,每组20例患者,观察3组患者疗效和副作用。结果:3组之间疗效两两比较采用Mann-Whitney秩和检验,强脉冲光组和激光组疗效无显著差异,而联合组疗效显著好于强脉冲光组（Z=7.123, P=0.024）和激光组（Z=6.024, P=0.030）。3组患者治疗后均无出现色素沉着加重、色素脱失病等不良反应。强脉冲光组和激光组的满意度无显著差异,而联合组的满意度显著好于强脉冲光组（Z=7.361, P=0.029）和激光组（Z=6.831, P=0.027）。结论:强脉冲光联合Nd:YAG激光治疗黄褐斑是一种安全有效的治疗方法,值得临床推广。     

Laser cladding of bioactive glass coatings

Laser cladding by powder injection has been used to produce bioactive glass coatings on titanium alloy (Ti6Al4V) substrates. Bioactive glass compositions alternative to 45S5 Bioglass^® were demonstrated to exhibit a gradual wetting angle–temperature evolution and therefore a more homogeneous deposition of the coating over the substrate was achieved. Among the different compositions studied, the S520 bioactive glass showed smoother wetting angle–temperature behavior and was successfully used as precursor material to produce bioactive coatings. Coatings processed using a Nd:YAG laser presented calcium silicate crystallization at the surface, with a uniform composition along the coating cross-section, and no significant dilution of the titanium alloy was observed. These coatings maintain similar bioactivity to that of the precursor material as demonstrated by immersion in simulated body fluid.     

Immediate cutaneous hypersensitivity after treatment of tattoo with Nd:YAG laser: a case report and review of the literature.

BACKGROUND: To our knowledge this is the first reported case of an immediate cutaneous reaction to Q-switched neodymium:yttrium-aluminum-garnet (Nd:YAG) laser tattoo removal. A 26-year-old female presented with two 6-year-old tattoos placed at different times. These were of different colors and had remained entirely asymptomatic since placement. There was a Mardi Gras mask on her thigh and a Tasmanian devil on her chest. With laser treatment of the Tasmanian devil, she experienced no untoward effects. However, with treatment of the Mardi Gras mask tattoo, she developed an extensive urticarial and indurated reaction 30 minutes posttreatment. The identical reaction occurred twice with subsequent laser treatments. Dermatology consulted allergy to provide prophylaxis against possible systemic reaction with subsequent Nd:YAG laser therapy. The patient was treated with 3 days of prednisone, cetirizine, and ranitidine before subsequent laser treatments. Prophylactic treatment suppressed all subsequent reactions to laser therapy. RESULTS: Delayed hypersensitivity to tattoo pigments occurring days to weeks after placement is well documented. There are no previous reports of immediate hypersensitivity during placement or laser removal. However, there are two previous reports of local and systemic delayed reactions after laser therapy. CONCLUSIONS: As far as we know, this is the first case report of immediate hypersensitivity after Nd:YAG laser treatment of a tattoo. Prophylactic treatment with steroids and antihistamines prevented reactions with subsequent laser treatments. Reactions after laser removal are rare, but may increase as popularity of skin art increases with the need for subsequent removal.     

Endoscopic laser surgery for subglottic stenosis in Wegener's granulomatosis

PURPOSE: Wegener's granulomatosis (WG) is a rare multisystem inflammatory disease, which infrequently involves the subglottic area and trachea. Treatment usually involves the use of immunosuppressive agents with corticosteroids. Some patients, however, continue to have symptoms of airway obstruction after clinical remission following the standard therapeutic regimen. OBJECTIVE: To investigate laser treatment for subglottic stenosis in five patients suffering from WG. MATERIALS AND METHODS: We endoscopically treated 5 patients with subglottic stenosis due to WG and airway obstruction by Nd:YAG and CO2 lasers. One of the patients had preoperative tracheostomy and after treatment was decannulated and could not breathe without dyspnea. Another patient required stenting of the subglottic area. RESULTS: All five patients were able to breathe without dyspnea after the treatment. Three patients were treated with an Nd:YAG laser but needed repeated laser treatment every four to six months, whenever they complained of dyspnea. The other two patients were treated with a CO2 laser; one of these patients had preoperative tracheostomy and was treated twice by CO2 laser and decannulated, with no further difficulty in breathing. The follow-up period was 1-5 years. CONCLUSIONS: Nd:YAG and CO2 lasers are recommended in the treatment of subglottic stenosis (SS) due to WG, particularly when the stenosis is in continuity or close proximity to the vocal cords.     

Overexposure analysis of pulsed distributed feedback laser source

The goal of this study is to assess the risk of overexposure, when DFB dye laser is used for medical treatment in pulsed mode operation. Results of experimental study showing an unexpected rise of energy in pulses of distributed feedback dye laser (DFDL) output due to temperature phase gratings in dye cell during passively Q switched and mode-locked operation is reported. This unintended increase in the number of pulses, pulse duration, per pulse energy may cause side effects, when used for selective photothermolysis. To probe this phenomenon the most commonly used Rh6G dye was excited with 10-20 pulses of second harmonic of a passively Q switched and mode-locked Nd:yttrium-aluminum-garnet(YAG) laser. The outputs of DFDL and Nd:YAG laser were recorded by an Imacon-675 streak camera. The peak of DFDL output pulses was found delayed proportionally from the peak of the Nd:YAG pulses by more than an interpulse period of excitation laser. A computer program was used to simulate the experimentally measured results to estimate the thermal decay constants and energy retained by medium. The delay between peaks of Nd:YAG (input) and DFDL (output) pulses was found to vary from 10 to 14 ns for various cavity lengths. It was interesting to note that for smaller inter-pulse periods the effect of gradual gain buildup satisfied the threshold conditions for some of the pulses that otherwise cannot lase. This may lead to unintended increase in energy fluence causing overexposure-induced bio effects.     

Regression of solid tumour using laser and 5-aminolevulinic acid in mice

Solid tumour reducing effect in Swiss albino mice induced with Dalton's Lymphoma Ascites tumour cells (DLA) and Ehrlich Ascites tumour cells (EA) was determined with the application of He-Ne and Nd:YAG lasers along with the photosensitising agent 5-Aminolevulinic acid (ALA). The experiment was designed with six groups and each group consisted of six animals. Animals in Groups I-III were injected with DLA cell lines and Groups IV-VI were injected with EA cell lines (1 x 10(6) in 0.1ml saline) subcutaneously in the right hind limb of mice to induce solid tumours. The tumour was further treated with photosensitiser induced laser therapy. The hyperthermic effect of Nd:YAG laser on tumour reduction was also evaluated. The results of the study suggest that the combination of He-Ne laser and 1 W Nd:YAG laser along with the photosensitiser 5-Aminolevulinic acid is a very effective therapeutic method for the treatment of tumour of DLA and EA cell lines. It is clear from the results that this mode of therapy very well depends on the type of tumour that has to be treated.     

Laser-assisted Zr/ZrO2 coating on Ti for load-bearing implants

Oxidized Zr alloys have been shown to exhibit lower friction and superior wear properties, suggesting that they could be used in hip and knee implants. However, conventional oxidation of Zr alloys above 500 °C, in dry air, for several hours has been shown to have detrimental effects on the substrate’s properties. In this work, we deposited pure Zr on Ti, then oxidized the coating using a continuous-wave Nd:YAG laser, which facilitated localized heating to elevated temperatures without affecting the substrate. Laser-assisted oxidation resulted in a 7 μm thick fully dense ZrO₂ layer on Zr in which an increase in oxidation kinetics was evident due to an increase in the laser power and/or the oxygen partial pressure. Due to its high surface energy and wettability, the wear rate of laser-oxidized Zr was two orders of magnitude less compared to that of as-deposited Zr. The oxidized coatings showed comparable in vitro biocompatibility to that of pure Ti and excellent in vitro cell–material interactions. This article reports the processing of Zr/ZrO₂ coatings on Ti using lasers, and the influence of laser parameters and oxygen partial pressure on the coating’s mechanical, microstructural, wear and in vitro biological properties using human osteoblast cells.     

The influence of photodynamic therapy on the wound healing process in rats

In photodynamic therapy (PDT), photosensitisers (PS) are used along with lasers for the treatment of tumors. The combined effect of photosensitisers and lasers on the wound healing process is studied using delta-aminolevulinic acid (ALA) (5 mg/kg) and hematoporphyrin derivative (HPD) (5 mg/kg) as photosensitisers in the open excision wounds of rats. The lasers used were He-Ne laser (3 J/cm2) and Nd:YAG laser (30 J/cm2). This study is important for understanding the healing process involved after PDT. Open excision wounds treated with He-Ne lasers in animals that received ALA as photosensitiser showed complete wound closure at the earliest by 13 +/- 1 days, and with results obtained for HPD and the combination of lasers with complete closing by 14 +/- 1 days. However, the control group of animals that received ALS or HPD with no laser treatment showed wound healing on the twentieth and eighteenth days with a deviation of one day and two days, respectively. ALA with the combination of Nd:YAG and He-Ne lasers and HPD with He-Ne laser alone does not show quicker wound healing effects. Histopathological results also gave similar results. Tensile strength measurements do not vary significantly from control group to the test group. ALA along with He-Ne laser of HPD along with the combination of He-Ne and low power Nd-YAG lasers are found to be ideal methods for quickening the wound healing process in rat.     

Long-Pulsed Nd:YAG Laser Treatment of Warts: Report on a Series of 369 Cases

Various treatment methods have been adopted in the management of warts; however, there is still no consensus on first-line treatment. This study was designed to evaluate the efficacy of long-pulsed Nd:YAG laser in the treatment of warts. Over the course of 1 yr, 369 patients with recalcitrant or untreated warts were exposed to a long-pulsed Nd:YAG laser. The following parameters were used: spot size, 5 mm; pulse duration, 20 msec; and fluence, 200 J/cm². No concomitant topical treatment was used. In all, 21 patients were lost during follow up; hence, the data for 348 patients were evaluated. The clearance rate was 96% (336 of the 348 treated warts were eradicated). The clearance rate of verruca vulgaris after the first treatment was very high (72.6%), whereas the clearance rate of deep palmopantar warts after the first treatment was low (44.1%). During a median follow-up period of 2.24 months (range, 2-10 months), 11 relapses were seen (recurrence rate, 3.27%). In conclusion, long-pulsed Nd:YAG laser is safe and effective for the removal or reduction of warts and is less dependent on patient compliance than are other treatment options.     

Effect of Nd:YAG laser irradiation on human dental enamel

The crystallographic alterations of the hydroxyapatite under the laser irradiation were evaluated by the x-ray diffraction pattern analysis and scanning electron microscopic observation. Recrystallization may occur in fused and resolidified dental enamel by the pulsed Nd: YAG laser irradiation. Two different grades of energy densities such as 400 pulses and 800 pulses were given to the powdered enamel. The irradiation was performed at a peak power of 500W with a pulse width of 10 msec.; the average output of 10W, spot size of 3mm and two pulses were given in every second. After the 800 pulses of Nd:YAG laser irradiation to the human dental enamel the x-ray diffraction pattern demonstrated both alpha-tricalcium phosphate and hydroxyapatite peaks. With the lower level of energy at 400 pulses, no significant differences were seen in the diffraction patterns between lased and unlased enamel. In scanning electron microscopic findings, there were no significant changes between lased and unlased enamel. When the unlased and lased enamel were exposed to acid solution, unlased enamel showed a honeycomb pattern, while the lased enamel showed preferentially removed prism core material.     

A histochemical study of the regeneration process after injury by pulsed Nd:YAG laser irradiation of root canals

Histological changes of rat dental pulp cells were followed after injury. The regeneration process after 3, 6 and 10 days was monitored. Mandibular incisors were irradiated with a pulsed Nd:YAG laser at 2 W and 20 pulses per sec (pps) for 5 sec and the pulp was examined histologically and immunohistochemically for TGF-beta1. Eruption of the developing tooth was disturbed for a short period only. Rapid formation of osteodentin was observed. After 3 days, a zone of fibrodentin matrix as well as newly formed vessels were found. Afterwards, regenerative dentin formation was observed accompanied by the formation of a layer of odontoblast-like cells in the damaged area. Immunohistochemical staining of TGF-beta1 showed that positivity was present in small tissue areas beneath the mantle dentin, the zone of fibrodentin matrix and odontoblast-like cells. These results indicate that pulsed Nd:YAG laser irradiation of rat incisor pulp induces formation of osteodentin, and TGF-beta1 plays a role during regeneration.     

Nd：YAG激光泪道成形术和鼻泪管支架术治疗慢性泪囊炎的疗效对比

目的比较Nd：YAG激光泪道成形术和鼻泪管支架术治疗慢性泪囊炎的临床效果。方法 93例（102眼）慢性泪囊炎患者随机分成两组,一组应用Nd：YAG激光泪道成形术治疗,另一组应用鼻泪管支架术治疗,比较两组的治疗效果。结果应用Nd：YAG激光泪道成形术治疗57眼,有效39眼（68.42%）;鼻泪管支架术治疗45眼,有效40眼（88.89%）,两组疗效差异有统计学意义（χ2=6.03,P〈0.01）。结论鼻泪管支架术相对于同样微创的Nd：YAG激光泪道成形术治疗慢性泪囊炎疗效更加稳定,手术成功率更高,不失为微创治疗慢性泪囊炎的首选术式。     

Laser-induced damage to transparent polymers: chemical effect of short-pulsed (Q-switched) Nd:YAG laser radiation on ophthalmic acrylic biomaterials. II. Study of monomer release from artificial intraocular lenses

Commercial intraocular lenses and polymer specimens, both poly(methyl methacrylate) (PMMA) and poly(2-hydroxyethyl methacrylate) p(HEMA), were subjected to various levels of irradiation from a Q-switched Nd:YAG laser, and then to extraction and sample-enrichment techniques. The extracts were analysed by capillary gas chromatography. In PMMA samples, residual contents of 0.05-0.89% (wt) MMA were found and it appeared that the laser radiation did not cause a detectable increase of the monomer content. No residual HEMA could be found in p(HEMA) samples before or after laser bombardment. It is concluded that the accidental exposure of lenses to Nd:YAG laser cannot produce a significant release of monomers. Depolymerization induced by laser is a process unlikely to occur at the energy levels used in ophthalmic surgery.     

Calcium phosphate coatings obtained by Nd:YAG laser cladding: physicochemical and biologic properties

The plasma spray (PS) technique is the most popular method commercially in use to produce calcium phosphate (CaP) coatings to promote fixation and osteointegration of the cementless prosthesis. Nevertheless, PS has some disadvantages, such as the poor coating-to-substrate adhesion, low mechanical strength, and brittleness of the coating. In order to overcome the drawbacks of plasma spraying, we introduce in this work a new method to apply a CaP coating on a Ti alloy using a well-known technique in the metallurgical field: laser surface cladding. The physicochemical characterization of the coatings has been carried out by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX). The biologic properties of the coatings have been assessed in vitro with human osteoblast-like MG-63 cells. The overall results of this study affirm that the Nd:YAG laser cladding technique is a promising method in the biomedical field.     

Nd:YAG激光治疗儿童后发障的临床观察

目的探讨Nd:YAG激光治疗儿童后发障的时机、效果及并发症。方法用Nd:YAG激光对65例87眼儿童后发障患者进行治疗。结果术后视力提高1行者7眼,占8%;提高2行者20眼,占22.9%;提高3行及以上者54眼,占62%;术后视力未提高者6眼,占6.8%。结论Nd:YAG激光治疗儿童后发障是一种安全有效的方法,并应尽早进行。