A comparative study on the effects of three types of laser irradiation at the apical stop and apical leakage after obturation

OBJECTIVE: The purposes of this study were to determine the degree of apical leakage using a dye penetration method after argon, pulsed Nd:YAG with or without black ink, or Er:YAG laser treatment and obturation, and to compare the results of three types of laser irradiation in vitro. SUMMARY BACKGROUND DATA: There have been only a few reports of the laser effect on apical leakage after laser treatment and obturation. METHODS: Seventy-five human extracted single root teeth were divided into five groups of 15 teeth each and prepared up to a #60 K-file size. One group served as the control and was not irradiated. The other four groups were irradiated with an argon laser at 0.3 W for 3 seconds at continuous mode, pulsed Nd:YAG laser at 2 W and 20 Hz for 4 seconds with or without black ink, and Er:YAG laser at 50 mJ per pulse and 4 Hz for 5 seconds. In each group, ten teeth for the apical leakage study were obturated and immersed in rhodamine B solution for 48 hours at 37 degrees C, and the others were used for the observation by scanning electron microscopy (SEM). All teeth were longitudinally bisected and observed by stereoscopy or SEM. RESULTS: After pulsed Nd:YAG laser treatment with black ink and obturation, the apical leakage degree (mean score: 0) was reduced compared to that in the control (mean score: 1.2) significantly (p < 0.05). SEM findings showed that specimens irradiated by pulsed Nd:YAG laser with black ink presented clean root canal walls with debris and smear layer evaporated, melted, fused, and recrystallized in most cases. CONCLUSION: These results suggest that pulsed Nd:YAG laser irradiation with black ink at the apical stop is useful for the reduction of apical leakage after obturation.     

Treatment of lymphangioma with Nd:YAG laser irradiation: a case report

OBJECTIVE: In this case report, the treatment of a buccal lymphangioma in a 9-year-old female was done using the Nd:YAG laser and the clinical outcome was evaluated. BACKGROUND DATA: The treatment of lymphangioma with the laser surgery using Nd:YAG and CO2 laser has become favorable due of a lack of postoperative pain and hemorrhage. METHODS: The lesion was treated with a pulsed Nd:YAG laser (d-lase 300, American Dental Laser, Detroit, MI). An exposure of 10 min each was performed at an interval of 10 days by the noncontact method with the energy density of 1 W, 10 Hz. RESULTS: It was observed that there was a great reduction of the lesion and a considerable reduction of the external facial volume. As the excision of the lesion was avoided in our present study, there was no pain and hemorrhage. A remarkable reduction of the tumor size could be observed visually within the five laser exposures. CONCLUSIONS: It can be concluded that if Nd:YAG laser therapy is used for reducing the tumor size as a primary treatment, the operation becomes easy and the recurrence may be less than with the conventional treatment, and an option of a surgical or laser excision could be reserved.     

Nd:YAG激光和Er:YAG激光联合Gluma脱敏剂治疗非手术牙周治疗后牙本质敏感疗效观察

目的 评价Gluma脱敏剂、Nd:YAG激光和Er:YAG激光单独及联合治疗非手术牙周治疗引起的牙本质过敏症(DH)的疗效.方法 选择60例经非手术牙周治疗后发生DH的牙周炎患者,共计180颗患牙.将患牙随机分为6组,每组30颗,其中A组:空白对照组;B组:Gluma脱敏剂组;C组:Nd:YAG激光组;D组:Er:YA...     

龈下刮治和根面平整术联合Er:YAG激光、Nd:YAG激光治疗牙周炎的研究进展

牙周炎是发生于牙周支持组织的慢性炎症性疾病,以牙周支持组织的进行性破坏为主要特征,是最常见的口腔疾病之一。龈下刮治和根面平整术(SRP)是治疗牙周炎最重要且最有效的非手术治疗方式,但其也有许多不足,如难以全部刮除深牙周袋、部分窄小的根分叉区域的牙结石及菌斑。近年来许多辅助治疗手段相继出现,激光广泛应用于牙周炎的辅助治疗中,目前临床常用的激光包括Er:YAG激光和Nd:YAG激光。Er:YAG激光既能作用于软组织也能作用于硬组织,能有效去除牙结石,且热损伤较小;Nd:YAG激光虽不能有效去除牙结石,且可能造成热损伤,但其具有较强的杀菌、止血止痛作用。本文结合国内外相关文献就SRP联合Er:YAG激光、Nd:YAG激光治疗牙周炎的研究进展做一综述,以期为牙周炎的临床治疗提供参考。     

Nd:YAG激光治疗后发性白内障对角膜内皮细胞的影响

目的：观察Nd：YAG激光治疗后发性白内障对角膜内皮细胞的影响。方法：后发性白内障患者21例30只眼,均行Nd：YAG激光治疗,术后用角膜内皮细胞显微镜观察患眼角膜内皮细胞的变化。结果：术后7及14d时患眼中央部位及6点处角膜内皮细胞的各项检测指标与术前比较均无明显变化。结论：2.6-3.2mj能量的Nd：YAG激光治疗后发性白内障对角膜内皮细胞无明显影响。     

大肠水疗联合地塞米松及双黄连粉针剂保留灌肠治疗溃疡性结肠炎的疗效分析

目的评价大肠水疗后地塞米松和双黄连粉针剂保留灌肠治疗溃疡性结肠炎多人临床疗效。方法选取溃疡性结肠炎160例,随即分成两组,其中对照组80例,采用口服硫氮黄氨嘧啶（SASP）;治疗组80例,大肠水疗的基础上,配合地塞米松和双黄连粉针剂保留灌肠治疗溃疡性结肠炎。结果治疗组80例。显效64例,有效14例,无效2例,总有效率97．5％;对照组80例,显效52例,有效10例,无效18例,总有效率77．5％。结论大肠水疗后,地塞米松和双黄连粉针剂保留灌肠治疗溃疡性结肠炎临床疗效肯定,值得推广。     

胆囊形态与胆囊结石相关性的临床研究

目的探讨胆囊形态与胆囊结石形成的相关性。方法分析本院自2005年至2007年对驻地单位40岁以上2230名健康体检者的肝胆超声检查结果,通过统计学处理胆囊形态异常组与胆囊形态正常组患者胆囊结石阳性率。结果胆囊形态异常组与胆囊形态正常组胆结石阳性率均存在统计学差异。结论胆囊形态异常是胆囊结石发病的危险因素。     

长脉冲1064nmNd：YAG激光治疗皮肤血管性疾病

目的探讨应用长脉冲1064nm Nd：YAG激光治疗皮肤血管性疾病的治疗效果。方法自2005年2月至2009年2月,应用长脉冲1064nm Nd：YAG激光治疗皮肤血管性疾病285例,对鲜红斑痣、草莓样血管瘤、混合性血管瘤、皮肤毛细血管扩张、血管痣及充血性增生瘢痕等皮肤血管性疾病,根据皮损的不同性质选定不同能量的光束进行照射,视情况重复治疗1—5次。治疗结束6个月后随访,评价治疗效果。结果285例中,有效245例,有效率为85．9％,治愈153例,治愈率为53．7％,出现色素性改变52例（18．2％）,均在数月至半年后恢复,遗留浅表性瘢痕10例（3．51％）,增生性瘢痕2例（0．7％）。结论长脉冲长脉冲1064nm Nd：YAG激光治疗皮肤血管性疾病具有起效快、疗效显著、不良反应小的优点,具有重要的临床应用价值。     

脉冲掺钕钇铝石榴石激光对增生性瘢痕成纤维细胞胶原合成的影响

Preventionandtreatmentofhypertrophicscar（HS）aredifficultinclinicandrehabilitationmedicine．Inthecurrentstudy，weobserveandcomparecollagensynthesisandexpressionlevelofprocollagenIgeneinfibroblastsfromnormalskinandculturedHStodeterminelaserparametersinhibitingcollagensynthesisoffibroblastsinHS．１Materialandmethod１．１Cellculture８subjectsincluding４withnormalskinand４withHSparticipatedinourstudy．Amongthesepatients，５males，３females，aged６～３４years．Durationofscarwaslessthan１２mont…     

Interstitial Laser Treatment of Venous Malformations

Objective: Venous malformations are aside from hemangiomas the most common vascular lesions observed in the pediatric age group. While interstitial Nd:YAG laser treatment was first used to treat hemangiomas in infancy, the mechanism of this treatment also can be used for venous malformations to reduce bulk and hypervascularisation, and improve contour and function.Study design: We reviewed our experience with the use of interstitial Nd:YAG laser therapy in treating complicated venous or mixed malformations. The lesions reported were particular troublesome because of significant cosmetic disfigurement, maceration or ulceration, bleeding, coagulopathy, painful swelling, and of potential functional impairment. During a 15-year period, 176 patients with predominantly venous malformations were treated by interstitial Nd:YAG laser treatment, and 157 of the 176 patients were treated additionally by transcutaneous Nd:YAG laser treatment with local ice cube cooling to protect the overlying skin. By using interstitial laser treatment, the laser beam was transmitted using a 0.6 mm bare fiber that was placed through an 16G abbocath into the lesion to be treated. The laser energy ranged from 5 W to 8 W in continuous mode. Color-coded duplex sonography was used for monitoring the procedure. Treatments were done under general anesthesia.Results:Overall, excellent results were achieved in 43% of patients and good results occured in 52%. In 5% treatment was deemed to have failed. Complications included paresthesia, dysesthesia, mild trismus, and local motoric plegia. All complications were transient and disappeared completely. Overall, satisfaction was high because of clear reduction of complaints, and all but 1 patient would have laser treatment again.Conclusions: On the base of our results we conclude that interstitial Nd:YAG laser treatment may successfully prevent enlargement and promote improvement with flattening of the lesion, less swelling, and improvement in the vascular red or bluish hue with minimal adverse effects.     

光动力疗法与Nd：YAG激光对胃胶原纤维损伤机制的比较

光动力疗法对于胃肠道肿瘤治疗效果令人鼓舞。但有关ＰＤＴ对胃肠道正常组织损伤的研究甚少。探讨了ＰＤＴ与Ｎｄ：ＹＡＧ激光对胃组织损伤的差异。结构发现：Ｎｄ：ＹＡＧ激光治疗过程中光纤周围组织温度明显高于ＰＤＴ组。光镜下二者均可造成明显组织损伤，但二周后修复方式不同，Ｎｄ：ＹＡＧ激光以纤维疤痕组织修复，而ＰＤＴ以正常组织再生修复，电镜发现Ｎｄ：ＹＡＧ激光致胃粘膜下胶原纤维明显损伤。     

Preventive effect of tooth fracture by pulsed Nd:YAG laser irradiation with diamine silver fluoride solution.

OBJECTIVE: The purpose of the present study was to evaluate the preventive effect of pulsed Nd:YAG laser irradiation with 38% diamine silver fluoride [Ag(NH3)2F] solution for the fracture of endodontically treated teeth in vitro. BACKGROUND DATA: There have been no reports on the preventive effect of tooth fracture using Nd:YAG laser with Ag(NH3)2F solution. MATERIALS AND METHODS: Twenty-eight human extracted teeth were used in this study. The teeth were randomly classified into four groups: control group, where tooth surfaces were not submitted to any treatment; group 1, where tooth surfaces were coated with 38% Ag(NH3)2F solution; group 2, where tooth surfaces were coated with Ag(NH3)2F solution and irradiated by pulsed Nd:YAG laser for 2 sec; and group 3, where tooth surfaces were coated with Ag(NH3)2F solution and irradiated by pulsed Nd:YAG laser for 10 sec. After preparation, shear tests were performed and the maximum load for the fracture was measured. Results were analyzed using the Scheffe test, and difference at p < 0.05 was considered significant. RESULTS: The failure load for group 2 (mean, 182.5 kg) had the highest mean value and differed significantly from those for the control group (mean, 146.3 kg) and group 1 (mean, 147.1 kg; p < 0.05). The failure loads for groups 1 and 3 (mean, 150.0 kg) did not differ significantly from that for the control group (p > 0.05). CONCLUSION: The results show that the application of 38% Ag(NH3)2F solution followed by pulsed Nd:YAG laser irradiation for 2 sec is useful for prevention of tooth fracture at endodontically treated teeth.     

Treatment of cervical dentin hypersensitivity by various methods using pulsed Nd:YAG laser

OBJECTIVE: The purpose of this study was to evaluate the results of two irradiated regions, the cervical and apical, for cervical dentin hypersensitivity treatment using pulsed a Nd:YAG laser with or without black ink. SUMMARY BACKGROUND DATA: There has been no reports on the irradiated area(s) except the cervical region for dentin hypersensitivity treatment using pulsed Nd:YAG laser. METHODS: A total of 180 teeth diagnosed with cervical dentin hypersensitivity in 54 (39 females, 15 males, aged 21 to 73) healthy adult patients were included in this study, and teeth were randomly divided into four groups of 45 each. Sensitivity was rated using a blast from a fully depressed air syringe on a four-grade scale both before and up to 2 months after laser treatment. The effectiveness was evaluated on the change in the degree of hypersensitivity after laser treatment. The tooth surfaces in groups 1 and 2 were observed by the replica model method using scanning electron microscopy (SEM). RESULTS: The methods of irradiation at the cervical regions were better than those at the apical regions except for the period 2 months later. The laser effect was enhanced by black ink at both areas. The effective (excellent and good) rate was decreased depending on the time in every group. SEM observation at the tooth surfaces from group 2 showed that dentinal tubules were occluded or narrowed after laser irradiation. CONCLUSIONS: These results show that the method of irradiation by a pulsed Nd:YAG laser at cervical regions with black ink is the most effective for cervical dentin treatment of hypersensitivity and recurrence by this method is less than in other methods.     

Interstitial Laser-Induced Thermotherapy (LITT): Comparison of In-Vitro Irradiation Effects of Nd:YAG (1064 nm) and Diode (940 nm) Laser

The Nd:YAG laser (1064 nm) is still the most commonly used laser system for interstitial LITT. However, high-power diode lasers are gaining a foothold in medical treatment by virtue of their compactness, reliability, and portability. This study investigates the feasibility of the 940 nm diode laser application for LITT procedures and enables a comparison of tissue effects using both laser systems. An in-vitro study was performed on porcine liver and muscle tissue using a bare fiber and a cooled, diffusely scattering applicator. Different power settings and exposure time combinations were chosen depending on the applicator type. Five applications were performed for each parameter combination. As a result, a clearly demarcated coagulation could be easily identified in each experiment. Carbonization effects were found to occur earlier in diode laser applications, while Nd:YAG laser applications allowed the use of higher power levels. The diode laser allows the creation of a certain volume of coagulation in a short period of time due to the lower optical penetration depth and this is usually accompanied by carbonization. Our results have shown that the 940 nm diode laser could be a possible alternative for the Nd:YAG laser especially in the interstitial treatment of pale tissue. Besides this it can be successfully applied even for the treatment of high absorbing tissue if small coagulation volumes are needed.     

High‐intensity Nd:YAG laser accelerates bone regeneration in calvarial defect models

High‐power pulsed lasers have been recently regarded to be anabolic to bone, but in vivo evidence is still lacking. This study aimed to investigate the capacity of bone repair using a high‐power, Q‐switched, pulsed, neodymium‐doped yttrium aluminium garnet (Nd:YAG) laser, using bilateral calvarial defect models having non‐critical sized, 5 mm (rat) or 8 mm (rabbit) diameter. One of the bilateral defects, which were all filled with collagen sponge or left empty, was irradiated with a Nd:YAG laser once every 2 days for 2 weeks at a constant total fluence rate (344 J/cm²), output power (0.75 W), pulse repetition rate (15 pps) and wavelength (1064 nm) and examined for the laser effect. The same experimental scheme was designed using a rabbit calvarial defect model implanted with sponge, which was explored for the dose effect of output power at 0.75 and 3 W with the same quantities of the other parameters. New bone formation was evaluated by micro‐computed tomography‐based analysis and histological observation at 4 weeks after surgery. Laser irradiation significantly increased new bone formation by approximately 45%, not only in the sponge‐filled defects of rats but also when the defects were left empty, compared to the non‐irradiated group. Consistently, both doses of output power (0.75 and 3 W) enhanced new bone formation, but there was no significant difference between the two doses. This study is one of the first to demonstrate the beneficial effect of Nd:YAG lasers on the regeneration of bone defects which were left empty or filled with collagen sponge, suggesting its great potential in postoperative treatment targeting local bone healing. Copyright © 2013 John Wiley & Sons, Ltd.     

A clinical study on the effects of pulsed Nd:YAG laser irradiation at root canals immediately after pulpectomy and shaping

OBJECTIVE: The effects of pulsed Nd:YAG laser irradiation for the treatment of root canals immediately after pulpectomy and shaping with regard to improvement of symptoms were evaluated clinically. SUMMARY BACKGROUND DATA: The effects of pulsed Nd:YAG laser irradiation for the treatment of root canals were experimentally investigated using an animal model, but not under clinical conditions. MATERIALS AND METHODS: Thirty-eight teeth from 29 patients were diagnosed as normal or irreversible pulpitis were used. After extirpation of pulp and shaping using a step-back technique and cleansing with 5% sodium hypochlorite (NaOCl) and 3% hydrogen peroxide (H2O2), laser irradiation was applied at 1 W and 15 pps for 1 second in 23 teeth (laser-treated group). Root canals were then obturated with gutta-percha points and sealer by the lateral condensation method. The condition of the obturations was confirmed radiographically. The control teeth were treated in the same way, but without laser irradiation. Occurrence of spontaneous pain was recorded 1 day after treatment and occurrence of percussion pain was recorded 1, 2, and 3 weeks after treatment. RESULTS: Effective ratio, which was the ratio of the number of "none" teeth to total teeth number in the laser-treated group, was higher than that in the control group, but there was no significant difference between 2 groups with regard to spontaneous and percussion pain (p > 0.05). CONCLUSION: These results suggest that the clinical application of pulsed Nd:YAG laser might be advantageous for the one-visit treatment of root canals immediately after pulpectomy shaping and to reduce postoperative pain.     

长脉冲1 064 nm Nd：YAG激光治疗婴幼儿皮肤血管瘤60例疗效研究

目的:观察长脉冲1064 nm Nd:YAG激光治疗婴幼儿皮肤血管瘤的临床疗效。方法:随机抽取我院2013年12月~2014年11月收治的60例皮肤血管瘤患儿作为研究对象,均采用长脉冲1064 nm Nd:YAG激光对60例患儿实施治疗,观察60患儿的临床治疗效果和不良反应情况。结果:60例患儿的临床治疗总有效率为96.7%。鲜红斑痣、单纯性血管瘤、混合型血管瘤患儿的临床治疗总有效率分别为94.4%、100.0%和90.0%;60例患儿的不良反应发生率为5.0%。结论:采用长脉冲1064 nm Nd:YAG激光对皮肤血管瘤患儿实施治疗,不良反应少,疗效确切。     

Nd:YAG激光治疗人工晶体前膜

目的：观察YAG眼科激光切除人工晶体前膜的疗效。方法：用MICR—OTUPTORVQ开关Nd：YAG眼科激光治疗人工晶体植入术后发生人工晶体前膜，经皮质类固醇激素点眼治疗疗效差的患者35例(37眼)。将双瞄准光处于正确聚焦位置，以使击破前膜的最低能量为度。34眼一次将前膜切除，1眼因出血，3d后再行激光前囊膜清除干净，2眼需行第二次激光切除。结果：Nd：YAG激光治疗一次性切除前膜35眼(94．6％)，二次切除2眼．35眼手术后视力有明显提高，56．7％视力增0．5～0．8，10．8％增1．0～1．5。无人工晶体损伤、眼压增高、眼前节无明显炎症反应。结论：YAG激光前膜切除术是一种安全有效的方法。     

强脉冲光与Q-开关倍频Nd：YAG激光治疗脂溢性角化病的临床疗效对比

【目的】比较强脉冲光与Q-开关倍频Nd：YAG激光治疗脂溢性角化病的临床疗效及不良反应。【方法】收集双侧面部均有脂溢性角化皮损的患者共15例,左侧皮损使用强脉冲光治疗,治疗间隔为4～5周,连续3次为一个疗程。右侧皮损使用Q-开关倍频Nd：YAG激光治疗,治疗间隔为4～5周,疗程为1～12次。患者和医生根据照片对每次治疗的疗效及不良反应进行评价。【结果】强脉冲光治疗3次后的疗效与Q-开关倍频Nd：YAG激光治疗1～2次后的疗效经患者和医生评价差异均无显著性（S=-5,P〉0．05;S=-4．5,P〉0．05）。强脉冲光治疗后色素沉着的发生率显著低于Q-开关倍频Nd：YAG激光（P〈0．01）,所有患者均未出现水疱、瘢痕及色素减退。【结论】强脉冲光和Q-开关倍频Nd：YAG激光均能有效地治疗脂溢性角化病。在使用Q-开关倍频Nd：YAG激光治疗时应适当降低能量密度,以防色素沉着的发生率。     

激光小血管吻合术后血清锌的变化

激光小血管吻合（ＬＡＭＡ）较之传统缝合吻合术具有快速、损伤小、利于较深手术野下操作等优点。用于ＬＡＭＡ的激光主要有ＣＯ２、Ａｒ＋和Ｎｄ：ＹＡＧ三种。本实验将１００只ＳＤ大鼠随机分为４组，在ＬＡＭＡ后０～１５３天中对大鼠血清锌水平的变化进行了观察，比较了这三种激光对１ｍｍ以下小动脉ＬＡＭＡ的结果。吻合颈总动脉互１３９条，ＣＯ２、Ａｒ＋和Ｎｄ：ＹＡＧＬＡＭＡ组远期通畅率分别为９５．９％、９７．７％和７３．９％（Ｐ＜Ｏ．００５）。血清锌以Ｎｄ：ＹＡＧ组降低显著（Ｐ＜Ｏ．０５）。对血锌与ＬＡＭＡ后组织损伤愈合过程的关系进行了讨论，认为ＣＯ２ＬＡＭＡ较Ｎｄ：ＹＡＧＬＡＭＡ为优．