Nd：YAG激光联合平阳霉素对兔耳静脉作用效应的研究

目的：探讨Nd：YAG激光联合平阳霉素（PYM）对兔耳静脉血管的作用效应。方法：健康新西兰白兔37只（74侧耳）随机分为A、B、C、D4组,A、B、C每组各12只,其中A组（实验组）每只兔耳注射PYM溶液0．3ml（浓度：4mg／ml）,第7d后于注射段行Nd：YAG激光扫描照射（能量密度为2547．8J／cm^2）;B、C组（对照组）分别给予PYM注射、Nd：YAG激光扫描照射;D组（空白组）1只。A、B、C组于第1d、3d、7d、14d、21d、28d各取4只兔耳静脉组织行光镜观察,取第14d、28d组织行透射电镜观察。结果：①光镜下：A组与B组比较,14d、21d、28d的静脉损伤程度有显著性差异（P〈0．05）：A组与C组比较,7d、14d、21d、28d的静脉损伤程度有显著性差异（p〈0．05）。②电镜下：A组与B、C组比较,28d时仍可见内皮细胞水肿,内膜肿胀及附壁血栓。结论：Nd：YAG激光联合平阳霉素较单一处理对兔耳静脉的损伤程度重、损伤作用时间长。     

Nd：YAG激光照射对兔面神经损伤的实验研究

目的探讨不同能量密度Nd：YAG连续激光对兔面神经的损伤效应及术后再生情况，为Nd：YAG激光治疗腮腺区深部海绵型血管瘤提供依据。方法根据临床治疗功率，采用5种不同能量密度Nd：YAG激光，分别对28只兔面神经进行照射。结果能量密度＜70J／cm2激光致面神经轻度变性，术后3周功能基本正常;能量密度140J／cm2激光致面神经中度变性;术后3周功能明显下降，6周基本恢复正常;能量密度240J／cm2激光致面神经不可逆损伤。结论Nd：YAG激光的热效应是面神经损伤的重要原因，且程度与能量呈正相关。     

Nd:YAG连续激光治疗颌面深部海绵状血管畸形的相关实验研究——Nd:YAG连续激光照射致兔面神经热效应的肌电研究

目的　观察不同剂量参数下Nd:YAG激光照射家兔面神经所致形态及支配肌功能改变。了解激光对面神经热效应的安全域为临床应用提供参考。方法　采用不同剂量组设计,观察28只家兔56侧面神经在各组Nd:YAG激光照射后神经升温状况、功能评价、面神经运动状况,支配肌肌电改变。结果　能量密度≤70Jcm2时Nd:YAG激光可致面神经轻度变性;术后3周支配肌功能基本恢复。能量密度≤140Jcm2时激光可致面神经中度变性,术后3周支配肌功能明显下降,6周基本恢复。能量密度为240Jcm2时激光致面神经不可逆损伤,面神经支配肌功能完全丧失。结论　Nd:YAG激光对家兔面神经的影响存在量效关系     

液氮冷冻联合Nd:YAG激光对兔耳静脉作用的效果观察

目的:观察液氮冷冻联合Nd:YAG激光照射对兔耳静脉的作用,评估该方法治疗静脉畸形的可行性。方法:将65只白兔随机分为4组。A、B、C为实验组,每组20只;D组为空白对照组,5只。以兔耳背中央静脉为实验模型,A组行液氮冷冻及Nd:YAG激光照射,B组行液氮冷冻,C组行Nd:YAG激光照射,D组不做处理。分别于实验处置后1、3、7、14、21 d对兔耳背中央静脉进行大体、光镜及电镜观察。结果:A组静脉血管内皮细胞、管壁平滑肌及构架结构均有明显损伤破坏,管腔内血栓形成,最终静脉闭锁。B、C组虽有血管内皮细胞损伤及血栓形成,但随后血栓逐渐溶解,血管修复。结论:冷冻联合激光照射对兔耳静脉有较强的损伤作用,具有治疗静脉畸形的可能性。     

Nd：YAG（1，064nm）激光在面颈部静脉畸形治疗中的应用：优点及挑战性

Nd：YAG激光是继硬化治疗及手术后治疗面颈部静脉畸形的较新方法。该文回顾了146例头颈部静脉畸形患者．年龄2个月-77．5岁，分析治疗效果及激光的应用参数。72例先前未经任何治疗．74例曾接受治疗。舌及颊黏膜的激光能量密度为103．1J／cm^2，皮肤为90．7J／cm^2，静脉球畸形的激光治疗能量密度为81．2J／cm^2。     

Nd：YAG激光照射对提高人牙周膜成维细胞增殖力的作用

目的观察Nd：YAG激光对人牙周膜成纤维细胞增殖和碱性磷酸酶（ALP）活性的影响。方法采用酶消化组织块法原代培养人牙周膜成纤维细胞，并进行波形蛋白及角蛋白的免疫细胞化学染色，对所培养的细胞进行鉴定。将牙周膜成纤维细胞分组，接受不同能量密度的Nd：YAG激光照射。测定牙周膜成纤维细胞碱性磷酸酶活性并观察其生长情况。结果5个实验组的细胞增殖速度及碱性磷酸酶含量均高于对照组，其中能量密度为60j／cm^2组、80j／cm^2组、100i／cm^2组与对照组相比有统计学的差异。结论低能量密度，短时间的Nd：YAG激光照射能促进牙周膜成纤维细胞的增殖，提高碱性磷酸酶活性。     

脉冲Nd:YAG激光照射对犬牙髓的影响

目的：探讨Nd：YAG激光对牙髓的安全阈值。方法：选择4条健康的本地杂种犬，先进行过敏模型制备，随机分为3组，分别给予：33J／cm^2、56J／cm^2和111J／cm^2激光照射，按照即刻、3d、7d、1个月4个时间段处死试验犬，实验牙经过固定、脱钙后，进行组织切片、光镜观察、病理分级。结果：牙髓反应均在3级以下，随激光照射能量的升高牙髓组织病理变化明显。在33～56J／cm^2之间，牙髓组织正常或反应轻微。结论：应用Nd：YAG激光进行牙齿过敏治疗时，其热效应可能对牙髓组织产生影响，33～56J／cm^2的激光能量不会对牙髓组织产生损害，能量较高将导致牙髓组织炎症，所以33～56J／cm^2的能量密度应为进行当次牙齿过敏治疗的安全阈值。     

Nd:YAG激光治疗口腔颌面部血管瘤疗效观察

目的：观察连续Nd:YAG激光治疗颌面部血管瘤的疗效。方法：采用1064nm的连续Nd:YAG激光对颌面部血管瘤进行照射，小的血管瘤1次照射即可，大的病灶分次照射，每次照射以病灶萎缩呈浅灰白色改变为度。结果：治愈率为62．50％，显效率为30．77％。结论：连续Nd:YAG附带同面部血管瘤疗效满意，具有良好的应用前景。     

脉冲Nd:YAG激光照射对髓腔温度的影响

目的 :通过离体牙实验 ,研究脉冲Nd :YAG激光照射牙面引起的牙髓腔内温度的变化 ,探讨激光脱敏的安全性和可行性。方法 :采用Nd :YAG激光机以 5J ,10J ,15J ,2 0J四种累积能量分别照射 1.5mm×2 .0mm大小的牙本质区域 ,测定相应牙髓腔内温度的变化。结果 :牙髓腔内的温度随激光能量的增加而升高 ,当能量密度在 5 5 .6J/cm2 — 111J/cm2 时 ,牙髓腔内的温度升高不会超过 5— 10℃。牙本质厚度与温度缺乏相关性 ,存在个体差异。结论 :5 5 .6J/cm2 — 111J/cm2 能量密度为本型激光脱敏的安全阈值。牙合面脱敏的能量密度比颈部略高 ,可达到 16 6 .7J/cm2 。     

脉冲Nd:YAG激光辅助极固宁脱敏剂治疗老年牙本质过敏症的临床研究

目的：研究脉冲Nd：YAG激光辅助极固宁脱敏剂治疗老年牙本质过敏症的临床效果。方法：实验组用脉冲Nd：YAG激光1W（30mJ／cm^2、15Hz）照射120sec后，涂擦极固宁脱敏剂3次;对照组强采用极固宁脱敏剂3次。结果：实验组即刻、3个月及6个月有效率分别为87．29％、81．36％和75．42％，对照组的有效率为79．09％、63．64％和52．73％。即刻两组差异无屁著性（P〉0．05），而3个月、6个月差异有显著性（P〈0．01）。结论：脉冲Nd：YAG激光辅助极固宁脱敏荆治疗老年牙本质过敏症是一种高效、作用持久、使用安全的方法。     

甲苯胺蓝为光敏剂的光动力疗法对龈下菌斑灭菌效果的研究

目的：研究甲苯胺蓝为光敏剂的光动力疗法对牙周龈下致病菌的灭菌效果。方法：从门诊25例牙周病病人随机提取龈下菌斑各1份，放人装有1mL预还原转送液的离心管，振荡，稀释。2h内送到微生物室，接种于牛心脑浸液平皿，在厌氧环境（含CO2、H1、N2的体积分数分别为10％、10％、80％）培养。培养出黑色菌落并与牙龈卟啉单胞菌标准菌株相鉴别。将菌样随机分为4组，A甲苯胺蓝组，甲苯胺蓝浓度分别为0．1、0．5、1．0、2．5g／L。B组光剂量组，光剂量为53、106、159、212mW／cm^2。C组光强度组，光强度为6、12、24、48J／cm^2。D组空白组。观察比较各组的灭菌效果，并确定最佳治疗组合。结果：光动力疗法的灭菌效果最佳组合为甲苯胺蓝1．0g／L＋光强度48J／cm^2＋光剂量212mW／cm^2，其灭菌效果平均23．45％。结论：本研究发现以甲苯胺蓝为光敏剂的光动力疗法对龈下菌斑有灭菌效果，最佳光敏剂浓度仍为1．0g／L，而龈下组所需光剂量和光强度均比前期研究的龈上组剂量大。不同病人的取菌条件不同，其灭菌效果也有差异。     

Substance removal on teeth with and without calculus using 308 nm XeCl excimer laser radiation

It was the aim of this in vitro study to determine the potential effects of 308 nm XeCl excimer laser radiation on root surfaces when used for removing calcified deposits. The source of laser radiation was a XeCl-excimer laser (MAX 10, Fa. Medolas, Germany) emitting ultraviolet radiation at a wavelength of 308 nm with a pulse duration of 60 ns. Subjects of irradiation were 60 extracted teeth which were divided into 2 groups of 30 samples each with (group 1) and without calculus (group 2). Specimens were irradiated with 800 laser pulses at 5 different energy-densities per pulse of 1.0 J/cm2, 2.0 J/cm2, 3.0 J/cm2, 4.0 J/cm2 and 5.0 J/cm2. For each parameter 6 samples (n=6) were exposed to 308 nm excimer-laser radiation. The ablation of hard tissue on the treated root surfaces was measured 3-dimensionally with a laser scanning device (100,000 surface points per sample; accuracy: 5 microm) and evaluated with a special image analyzing software (volume, mean, median, standard deviation). In addition, a scanning electron microscopic (SEM) evaluation of the irradiated root surfaces was performed. Statistical analysis was done using ANOVA with the Scheffé-test. The lowest amount of ablation on teeth without calculus was induced with 14.01 (+/-5.86) microm using laser radiation at an energy density of 2.0 J/cm2. Maximum tissue removal in this sample group was obtained with 56.67 (+/-21.05) microm with laser treatment at an energy density of 5.0 J/cm2. While no ablation of dental cementum was detectable after irradiating root surfaces without calculus at 1.0 J/cm2, a strong removal of calculus with a mean value of 31.91 (+/-4.2) microm was observed under these conditions. The results seem to indicate that a selective removal of subgingival calculus creating a homogenous shape of the root surface with 308 nm excimer laser radiation is possible. Furthermore, no signs of the formation of a smear layer nor the induction of thermal side-effects were observed.     

Nd：YAG激光照射治疗牙本质敏感症的能量密度范围的离体牙研究

目的：探索Nd：YAG激光照射牙本质后,既能显著降低其通透性,又不引起表面形态破坏的能量密度范围。方法：10个离体磨牙均切成6个2mm×3mm×4mm的牙本质块,随机分为：空白对照组、Gluma组、50、100、200、450J/cm2激光组。37%磷酸处理,每组随机取8个标本浸入2%亚甲蓝溶液5h,体视显微镜下测量染液渗透深度,另2个标本观察表面形态变化。结果：1）染液渗透深度,空白对照组、Gluma组、50J/cm2,100J/cm2,200J/cm2,450J/cm2激光组分别为（3.211±0.345）、（1.714±0.475）、（3.058±0.193）、（2.603±0.389）、（1.979±0.380）、（1.156±0.397）mm。50J/cm2激光组牙本质通透性与对照组无差异,其余各组与对照组相比均明显下降,且随着激光能量升高,通透性降低。其中200J/cm2激光组的牙本质通透性与Gluma组相当。2）牙本质表面观察,450J/cm2激光组牙本质表面有显著改变,可见大小不一,形态不规则的凹坑。结论：Nd：YAG激光用于治疗牙本质敏感症时,考虑到有效性和安全性,建议能量密度为200~450J/cm2。     

红光结合血卟啉单甲醚光动力疗法治疗微静脉畸形的实验研究

目的:通过鸡冠动物模型了解红光结合光敏剂血卟啉单甲醚(hematoporphyrin monomethylether,HMME)在光动力疗法治疗微静脉畸形中的治疗效果和适宜治疗参数。方法:48只鸡随机分组,处理组分别注射不同剂量的HMME后,半导体激光(红光)或氩离子泵浦染料激光不同能量密度分组照射,照射后肉眼和光镜下观察比较组织损伤程度并测量损伤深度。结果:红光结合HMME照射能引起鸡冠颜色变白、血管数量减少等形态学改变。HMME10mg/kg、15mg/kg剂量组中,在相同功率密度时,红光高能量密度照射组(240J/cm2)所造成损伤深度(分别为1.2225±0.8457mm,2.2800±1.3665mm)均显著大于氩离子泵浦染料激光不同能量密度的各照射组(P<0.05)。适宜治疗参数为HMME剂量10mg/kg,红光能量密度120-240J/cm2。结论:红光结合HMME光动力疗法有可能对增厚或结节型微静脉畸形实现更佳的治疗效果。     

Nd:YAG激光对口腔鳞癌CAL-27细胞迁移的影响

目的探讨1064 nm Nd:YAG激光对口腔鳞癌CAL-27细胞迁移的影响。方法体外培养鳞癌CAL-27细胞,取处于对数生长期的细胞接种于24孔板中并继续培养24 h,分0、120、240、360、480 s五组接受激光照射,对应剂量为0、44.4、88.8、133.2、177.6 J/cm~2,划痕后分别于0、12、24、48 h在倒置显微镜下观察划痕变化并拍照,以研究激光照射对细胞迁移影响。结果低剂量激光照射后细胞划痕区域愈合程度提高,而高剂量激光照射后,细胞划痕区域愈合程度降低。结论低剂量Nd:YAG激光照射对鳞癌CAL-27细胞迁移有一定促进作用,而高剂量Nd:YAG激光照射则会对鳞癌CAL-27细胞的迁移产生明显抑制作用。     

Inhibitory effects of a super pulsed carbon dioxide laser at low energy density on periodontopathic bacteria and lipopolysaccharide in vitro

OBJECTIVE AND BACKGROUND: Previous studies have described the effect of irradiation by a carbon dioxide (CO2) laser at high energy density on oral bacteria, and various side-effects have also been observed. However, no published studies have examined the effect of irradiation by a CO2 laser at low energy density on oral bacteria. The purpose of this study was to investigate the effects of super pulsed CO2 laser irradiation on periodontopathic bacteria and lipopolysaccharide (LPS). Methods: Bacterial suspensions of two species of periodontopathic bacteria received laser irradiation at energy densities of 0-12.5 J/cm2. The suspensions were then spread over agar plates and incubated anaerobically. The bactericidal effects were evaluated based on colony formation. Samples of LPS were laser-irradiated at energy densities of 0-12.5 J/cm2. The biological activity was measured, and LPS was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). RESULTS: The irradiation at low energy densities of 7.5 and 12.5 J/cm2 killed more than 99.9 and 99.999% of Porphyromonas gingivalis and more than 99% of Actinobacillus actinomycetemcomitans was sterilized by the irradiation at 7.5 J/cm2. LPS biological activity was significantly decreased by laser irradiation at energy densities of more than 7.5 J/cm2 (p < 0.05), and the components of LPS analyzed by SDS-PAGE was diminished non-specifically. CONCLUSION: The results indicate that CO2 laser irradiation at low power is capable of bactericidal effect on periodontopathic bacteria and decreasing LPS activity.     

Does LLLT stimulate laryngeal carcinoma cells? An in vitro study

Low level laser therapy (LLLT) has been used successfully in biomedicine and some of the results are thought to be related to cell proliferation. The effects of LLLT on cell proliferation is debatable because studies have found both an increase and a decrease in proliferation of cell cultures. Cell culture is an excellent method to assess both effects and dose of treatment. The aim of this study was to assess the effect of 635nm and 670 nm laser irradiation of H.Ep.2 cells in vitro using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide). The cells were obtained from squamous cell carcinoma (SCC) of the larynx and were routinely processed from defrost to the experimental condition. Twenty-four hours after transplantation the cells were irradiated with doses ranging from 0.04 to 0.48J/cm2 for seven consecutive days (5 mW diode lasers: 635nm or 670 nm, beam cross-section approximately 1 mm) at local light doses between 0.04 and 0.48 J/cm2. The results showed that 635nm laser light did not significantly stimulate the proliferation of H.Ep.2 cells at doses of 0.04 J/cm2 to 0.48 J/cm2, However, 670nm laser irradiation led to an increased cell proliferation when compared to both control and 635nm irradiated cells. The best cell proliferation was found with 670nm laser irradiated cultures exposed to doses of doses of 0.04 to 0.48 J/cm2. We conclude that both dose and wavelength are factors that may affect cell proliferation of H.Ep.2 cells.