Nd:YAG water mist laser treatment for giant gestational gingival tumor: A case report

BACKGROUND This case of gestational gingival tumor is huge and extremely rare in clinical practice.As the growth location of this gingival tumor is in the upper anterior tooth area,it seriously affects the pregnant woman's speech and food,causing great pain to the patient.The use of Nd:YGA water mist laser to remove the gingival tumor resulted in minimal intraoperative bleeding,minimal adverse reactions,and good postoperative healing,which is worthy of clinical promotion and application.CASE SUMMARY The patient,a pregnant woman,reported a large lump in her mouth on the first day of postpartum treatment.Based on medical history and clinical examination,the diagnosis was diagnosed as gestational gingival tumor.Postoperative pathological biopsy also confirmed this diagnosis.The use of Nd:YAG water mist laser to remove the tumor resulted in minimal intraoperative bleeding,clear surgical field of view,short surgical time,and good postoperative healing.CONCLUSION In comparison to traditional surgery,Nd:YAG water mist laser surgery is minimally invasive,minimizes cell damage,reduces bleeding,ensures a clear field of vision,and virtually eliminates postoperative edema,carbonization,and the risk of cross infection.It has unique advantages in oral soft tissue surgery for pregnant patients.Therefore,the clinical application of Nd:YAG water mist laser for the treatment of gestational gingival tumors is an ideal choice.

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

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

芪参补气活血养颜汤联合Q开关Nd∶YAG激光治疗女性黄褐斑的美学效果观察

目的:探讨芪参补气活血养颜汤联合Q开关Nd∶YAG激光治疗女性黄褐斑的美学效果。方法:选取笔者医院2019年1月-2022年1月收治的80例黄褐斑女性作为研究对象,按照随机数字表法分为观察组42例(采用芪参补气活血养颜汤联合Q开关Nd∶YAG 1064 nm激光治疗)和对照组38例(采用Q开关Nd∶YAG 1064 nm激光治疗)。观察两组的临床疗效,中医症状积分,皮肤状况,黄褐斑面积及颜色,不良反应发生率。结果:治疗后,观察组患者的总有效率为97.62%,高于对照组患者的84.21%(P<0.05)。治疗后,观察组患者情绪低落、胸胁胀痛、经行乳胀、口苦咽干等上述中医症状积分均低于对照组患者(P<0.05)。治疗后,观察组黑素指数、红斑指数及皱纹指数均低于对照组(P<0.05)。治疗后,观察组黄褐斑面积及颜色评分均低于对照组(P<0.05)。治疗后,观察组患者的总不良反应发生率与对照组患者比较差异无统计学意义(P>0.05)。结论:芪参补气活血养颜汤联合Q开关Nd∶YAG1064 nm激光能够提高黄褐斑治疗的临床疗效,改善患者临床症状,改善皮肤状况,减少黄褐斑面积及颜色,安全性较高,值得临床推广。

LD环状侧面均匀泵浦Nd∶YAG激光振荡器

激光二极管(Laser Diode,LD)环状侧面均匀泵浦的激光振荡器具有结构简单、光束质量高、单脉冲能量大等特点,常常在高能脉冲固体激光器中作为主振荡功率放大(MOPA)结构的振荡器,一直是国内外科研人员研究的重要方向之一。本论文通过Zemax软件对不同激光二极管排列方式以及不同工作物质吸收系数对吸收光场的影响的进行了仿真。基于仿真结果,设计了一种20个bar条串联的环状侧面泵浦结构,以提高晶体吸收的均匀性。通过该环状侧泵结构,结合超高斯非稳腔设计,搭建了一种双棒串接激光振荡器进行实验研究。该振荡器实现了在100 Hz重复频率下,单脉冲能量为496 mJ、脉冲宽度为12.4 ns的1064 nm激光输出,光束质量优于9 mm·mrad,光-光转换效率为18.5%。并且该振荡器可以维持光轴稳定不变的同时,实现20 ns脉宽以内变档可调。实验结果证明了该环状侧面均匀泵浦结构可靠有效,为MOPA结构振荡器选取提供了一种有效的方案。

双波长LD泵浦Nd^(3+)∶YAG免温控被动调Q激光器的研究

传统的固体激光器体积、重量大,功耗高,限制了其在空间受限设备中的应用。被动调Q的LD泵浦免温控固体激光器省去了复杂的温度控制装置,调Q机构简单,能够满足复杂温度环境的特殊应用场景的小型化、低功耗要求。提出了基于双波长LD泵浦实现宽温度范围免温控阈值自适应的1.06μm激光脉冲输出方法。基于Nd∶YAG晶体设计了角锥棱镜谐振腔,仿真分析了LD泵浦源到激光棒的面心距对热负载的影响,并确定4 mm的最佳面心距。数值分析了相同泵浦功率下-40~60℃温度范围内激光静态能量输出变化,以及不同初始透过率的可饱和吸收体对激光阈值脉宽的影响。计算结果表明在-37℃~60℃范围内,阈值脉宽都在200μs以下,阈值脉宽最低点达到了29.4μs。构建主波实时探测的阈值自适应调节装置并搭建实验系统,实验结果表明,在温度范围为-35~60℃时,阈值脉宽变化范围为40~180μs。采用激光腔体一体加工成型,应用轻量化的铝合金材料,实现工程化应用,体积83.5 mm×44 mm×29.5 mm,重量约为230 g。在23.8%初始透过率的饱和吸收体条件下实现单脉冲输出能量42 mJ,脉冲宽度5.2 ns。

低通量Q开关Nd∶YAG激光联合微针导入氨甲环酸治疗黄褐斑

目的评估低通量Q开关Nd∶YAG(QSNY)激光单一治疗与其联合微针导入氨甲环酸治疗黄褐斑的疗效差别,并基于皮肤镜分型分析不同类型黄褐斑的最佳治疗方式。方法收集2022年1月—2023年12月就诊的黄褐斑患者的临床资料,比较QSNY激光单一治疗组(对照组,23例)与QSNY激光联合微针导入氨甲环酸治疗组(联合组,23例)治疗3次后改良黄褐斑面积和严重程度指数(mMASI)评分、皮肤镜检查总评分(TDS)、医生临床评估(PGA)和不良反应的发生率。结果2组患者治疗后mMASI评分均降低,联合组的mMASI评分改善优于对照组(P<0.05);2组患者治疗后TDS均降低,联合组改善程度更佳,差别有统计学意义(P<0.05)。与治疗前比较,联合组治疗后毛细血管扩张明显改善,差别有统计学意义(P<0.001)。2组患者的PGA评分比较,差别无统计学意义(P>0.05)。2组患者治疗后均未发现明显的不良反应。结论QSNY激光联合微针导入氨甲环酸治疗黄褐斑的疗效优于单一激光治疗,前者对血管增生和表皮色素沉着明显的黄褐斑更有利。

Clinical usefulness of transpapillary removal of common bile duct stones by frequency doubled double pulse Nd:YAG laser

AIM: To study the efficacy and the safety of laser lithotripsy without direct visual control by using a balloon catheter in patients with bile duct stones that could not be extracted by standard technique. METHODS: The seventeen patients (7 male and 10 female; mean age 67.8 years) with difficult common bile duct (CBD) stones were not amenable for conventional endoscopic maneuvers such as sphincterotomy and mechanical lithotripsy were included in this study. Laser wavelengths of 532 nm and 1064 nm as a double pulse were applied with pulse energy of 120 mJ. The laser fiber was advanced under fluoroscopic control through the ERCP balloon catheter. Laser lithotripsy was continued until the fragment size seemed to be less than 10 mm. Endoscopic extraction of the stones and fragments was performed with the use of the Dormia basket and balloon catheter. RESULTS: Bile duct clearance was achieved in 15 of 17 patients (88%). The mean number of treatment sessions was 1.7 ± 0.6. Endoscopic stone removal could not be achieved in 2 patients (7%). Adverse effects were noted in three patients (hemobilia, pancreatitis, and cholangitis). CONCLUSION: The Frequency Doubled Double Pulse Nd:YAG (FREDDY) laser may be an effective and safe technique in treatment of difficult bile duct stones.

Microstructure,properties and first principles calculation of titanium alloy/steel by Nd: YAG laser self-fluxing welding

The experiment of Nd： YAG pulsed laser self-fluxing welding for 304 stainless steel/Ti6Al4V titanium alloy dissimilar metal was carried out. The microstructure properties of welded joint were analyzed by SEM, EDS and XRD. The equilibrium lattice constants, enthalpies of formation, cohesive energies, mechanical properties, Debye temperatures and valence electron structures of Ti-Fe intermetallic compounds （IMCs） were calculated by the first principle pseudopotential plane wave method based on density functional theory （DFT）. According to the thermodynamic data of Ti-Fe-Cr compounds, the Gibbs free energy per mole of compound at different temperatures was calculated and their thermal stability was compared. The results show that there are no macroscopic cracks in the welded joints, and the IMCs distributed evenly along the welding interface exhibits 3 distinct layers of microstructure with different colors. The welds interface generates IMCs of TiFe, TiFe 2 and a small amount of Ti 5Cr 7Fe 17 IMCs. Ti-Fe IMCs with high thermodynamic stability and easy alloying formation. The results of Gibbs free energies show that the sequence of precipitates in the interface is Ti 5Cr 7Fe 17 , TiFe 2 and TiFe in high temperature during the metallurgical reaction. The G/B values of Ti-Fe IMCs are greater than the critical value of 0.5, indicating that it is an intrinsic brittleness.

A high-power high-stability Q-switched green laser with intracavity frequency doubling using a diode-pumped composite ceramic Nd:YAG laser

We successfully obtain a high-average-power high-stability Q-switched green laser based on diode-side-pumped composite ceramic Nd：YAG in a straight piano-concave cavity. The temperature distribution in composite ceramic Nd：YAG crystal is numerically analyzed and compared with that of conventional Nd：YAG crystal. By using a composite ceramic Nd：YAG rod and a type-II high gray track resistance KTP （HGTR-KTP） crystal, a green laser with an average output power of 165 W is obtained at a repetition rate of 25 kHz, with a diode-to-green optical conversion of 14.68%, and a pulse width of 162 ns. To the best of our knowledge, both the output power and optical-to-optical efficiency are the highest values for green laser systems with intracavity frequency doubling of this novel composite ceramic Nd：YAG laser to date. The power fluctuation at around 160 W is lower than 0.3% in 2.5 hours.

Comparison of laser iridotomy using short duration532-nm Nd: YAG laser (PASCAL) vs conventional laser in dark irides

AIM: To evaluate the outcome of laser iridotomy using532-nm Nd: YAG laser(PASCAL) with short pulse duration and Nd: YAG laser compared to conventional combined laser iridotomy.METHODS: Retrospective, nonrandomized, comparative case series. Forty-five eyes of 34 patients underwent laser iridotomy. Twenty-two eyes underwent iridotomy using short duration PASCAL and Nd: YAG laser, and 23 eyes underwent iridotomy using conventional combined laser method. The average settings of PASCAL were60 μm and 700-900 m W with a short duration of 0.01 s to reduce the total applied energy. The conventional laser was 50 μm and 700-900 m W for 0.1s. After photocoagulation with these laser, the Nd: YAG laser was added in each group. Endothelial cell counts of preiridotomy and 2mo after iridotomy were measured and compared.RESULTS: All eyes completed iridotomy successfully.The total energy used in the PASCAL group was 1.85 ±1.17 J. Compared to conventional laser 13.25 ±1.67 J, the energy used was very small due to the short exposure time of PASCAL. Endothelial cell counts were reduced by0.88% in the PASCAL group and 6.72% in the conventional laser group(P =0.044). The change in corneal endothelial cell counts before and after iridotomy was significant in conventional combined laser iridotomy group(P =0.004).CONCLUSION: Combined PASCAL and Nd:YAG laseriridotomy is an effective and safe technique in the dark brown irides of Asians. Furthermore, the short duration of exposure in PASCAL offers the advantages of reducing the total energy used and minimizing the corneal damage.

Pulsed Nd:YAG laser cladding of high silicon content coating on low silicon steel

A pulsed Nd：YAG （yttrium aluminum garnet） laser-based technique was employed to clad low silicon steel with preplaced Si and Fe mixed powders for high Si content. The surface morphology, microstructural evolution, phase composition, and Si distribution, within the obtained cladding coatings, were characterized by optical microscopy （OM）, field emission scanning electron microscopy （FE-SEM）, with associated energy dispersive spectroscopy （EDS）, transmission electron microscopy （TEM）, and X-ray diffraction （XRD）. The microhardness was also measured along the depth direction of the specimens, A crack- and pore-free cladding coating through excellent metallurgical bonding with the substrate was successfully prepared on low silicon steel by means of optimized single-track and multi-track laser cladding. The phases of the coating are a-Fe, T-Fe, and FeSi. The high microhardness of the lasercladding zone is considered as an increase in Si content and as the refined microstructure produced by the laser treatment. The Si contents of the cladding coatings were about 5.8wt% in the single-track cladding and 6.5wt% in the multi-track cladding, respectively.

Passively Q-Switched Nd,Cr:YAG Laser Simultaneous Dual-Wavelength Operation at 946 nm and 1.3μm

A diode-end-pumped Q-switched high-efficiency Nd, Cr：YAG laser with simultaneous dual-wavelength emission at 946nm and 1.3μm is demonstrated. The maximum output power of 1.93 W with simultaneous dual-wavelength operation is achieved at an absorbed pump power of 13.32 W and an absorbed slope efficiency of 15.15%. The maximum optical-optical efficiency is 14.49% with pulse widths of 16.38ns at 946nm and 26.65ns at 1.3μm. A maximum total repetition rate of 43.25 kHz is obtained.

High power high beam quality diode-pumped 1319-nm Nd:YAG oscillator-amplifier laser system

This paper demonstrated a high power and high beam quality diode-pumped 1319-nm Nd：YAG master oscillator-power amplifier laser system. A thermally near-unstable resonator with four-rod birefringence compensation fiat-fiat cavity was adopted as the master oscillator. A solid etalon was inserted in the unidirectional ring resonator to compress the laser linewidth. Under a repetition rate of 500 Hz and pulse width of 160 μs, the master oscillator delivers an average output power of 16.8 W at 1319 nm with linear polarisation, beam quality factor M^2=1.16 and linewidth of 3.2 GHz. A double-pass power amplifier with two amplifier stages was employed for higher power scaling and the output power was amplified to be 25.9 W with M^2 = 1.43.

Effects of 946-nm thermal shift and broadening on Nd^(3+):YAG laser performance

Spectroscopic properties of flashlamp pumped Nd^3＋：YAG laser are studied as a function of temperature in a range from-30℃ to 60℃. The spectral width and shift of quasi three-level 946.0-nm inter-Stark emission within the respective intermanifold transitions of ^4F3/2→^4I9/2are investigated. The 946.0-nm line shifts toward the shorter wavelength and broadens. In addition, the threshold power and slope efficiency of the 946.0-nm laser line are quantified with temperature.The lower the temperature, the lower the threshold power is and the higher the slope efficiency of the 946.0-nm laser line is,thus the higher the laser output is. This phenomenon is attributed to the ion-phonon interaction and the thermal population in the ground state.

腔外旋转泵浦的Nd∶YAG固体激光器研究

固体激光器的热管理仍然是高功率激光系统发展的一个持续挑战。在激光系统中增益介质和泵浦光之间引入相对运动是一种高效的热管理方案。针对静止泵浦,旋转增益介质泵浦以及泵浦光旋转泵浦3种泵浦方式,借助有限元数值模拟方法分析了Nd∶YAG晶体的温度分布。泵浦光以800 r/min旋转时,在35 W泵浦功率下,使用标准的热沉冷却技术,晶体的最高温度达到约36℃,仅增加约16℃,这远低于静止泵浦时的142℃。实验设计并演示了一种腔外旋转泵浦的Nd∶YAG激光器,得到了12.2 W的1 064 nm连续输出,斜率效率为37.2%,这大于静止时的35.1%,实验结果与理论结果相符合。研究表明,腔外旋转泵浦的固体激光器拥有高效的热管理。

Diode end-pumped self-Q-switched and mode-locked Nd,Cr：YAG /KTP green laser

We first experimentally demonstrate a laser-diode end-pumped self-Q-switched and mode-locked Nd,Cr：YAG green laser with a KTP crystal as the intra-cavity frequency doubler. The device produces an average output power of 680 mW at 532 nm. The corresponding pulse width of the Q-switched envelope of the green laser is 170 ＋ 20 ns. The mode-locked pulses have a repetition rate of approximately 183 MHz and the average pulse duration is estimated to be around sub-nanosecond. It is found that the intra-cavity frequency doubling greatly improves the modulation depth and stability of the mode-locked pulses within the Q-switched envelope.

Effects of output waveforms on penetration for Nd :YAG laser welding

By using a Nd: YAG laser welding system devised for transmitting continuous, rectangular and pulsed waveforms, comprehensive and deep investigation is focused on the effects of several parameters of rectangular waveform and pulsed output wave superimposed on a rectangular waveform on the penetration depth of weld. Research results indicate that the average power, duty cycle, frequency and peak power of rectangular wave affect the weld penetration depth to different extent. Results of experiments and analysis also indicate that the pulse delay time, pulse width and the power ratio of pulse to rectangular waveform seriously influence the penetration when the pulsed wave is superimposed on a rectangular waveform.

后发性白内障患者行Nd∶YAG激光术后视觉质量

目的:探究角膜/屈光分析仪OPD-Scan Ⅲ评估后发性白内障患者行Nd∶YAG激光术后视觉质量。方法:回顾性研究。选取2021-05/2023-04于我院行Nd∶YAG激光后囊膜切开术治疗的后发性白内障患者98例98眼,采用角膜/屈光分析仪OPD-Scan Ⅲ获取患者高阶像差参数(彗差、球差和三叶草像差)和视觉质量参数[斯特列尔比(SR)和人眼调制传递函数(MTF)曲线中4 mm面积比(AR)],比较患者术前,术后1 wk,3 mo时视力、高阶像差和视觉质量。结果:纳入患者手术前后裸眼远视力(UDVA)、裸眼中视力(UIVA)、裸眼近视力(UNVA)、彗差、球差、三叶草、SR和AR比较均有差异(均P<0.001)。术后1 wk,3 mo UDVA、UIVA、UNVA、彗差、球差、三叶草、SR和AR与术前比较均有差异(均P<0.05)。术后3 mo UDVA、UIVA、UNVA、SR和AR与术后1 wk比较均有差异(均P<0.05),术后3 mo彗差、球差、三叶草与术后1 wk比较均无差异(均P>0.05),术后3 mo球差、三叶草与SR均呈负相关(r_(s)=-0.427,P=0.009;r_(s)=-0.436,P=0.010),三叶草与AR呈负相关(r_(s)=-0.406,P=0.015)。结论:后发性白内障患者Nd∶YAG激光术后视力改善,使用角膜/屈光分析仪OPD-Scan Ⅲ系统反映患者视觉质量具有较高的临床价值。

Nd∶YAG和Er∶YAG激光联合辅助治疗伴2型糖尿病的慢性牙周炎的临床疗效分析

纳入合并2型糖尿病的慢性牙周炎患者30例,采用分口设计法,将同患者左侧牙列设为试验组,行牙周基础治疗,以及Nd∶YAG和Er∶YAG激光联合辅助治疗,右侧牙列设为对照组,仅行牙周基础治疗。治疗前后检测牙周及CBCT影像指标,并行组间比较。治疗前2组全部指标无统计学差异(P>0.05)。治疗后3个月,试验组的出血指数(BI)和探诊深度(PD)明显低于对照组(P<0.05);治疗后6个月,试验组的BI、PD以及附着丧失(AL)明显低于对照组,牙槽骨内剩余牙根表面积和牙根体积明显高于对照组(P<0.05)。Nd∶YAG和Er∶YAG激光联合辅助下的牙周基础治疗较单纯牙周基础治疗对伴2型糖尿病的慢性牙周炎疗效更为显著。

High-Power Passively Q-Switched Nd:YAG Laser at 1112 nm with a Cr^(4+):YAG Saturable Absorber

A high-power passively Q-switched Nd：YAG laser operating at lll2nm with Cr4＋：yAO as a saturable absorber is demonstrated. Under 808 nm diode-direct pumping, the maximum average output power of 2.73 W is achieved at the pump power of 16.65 W, corresponding to an optical-to-optical conversion efficiency of 16.4%. At the same time, the pulse width, pulse repetition rate, single pulse energy and peak power are 27.2ns, 9 kHz, 303.3#3 and 11.2kW, respectively. As far as we know, the result gives the highest average output power at 1112nm generated by an 808 nm diode-end-pumped Nd：YAG laser.