Kr：F准分子激光对大鼠牙髓的影响

目的 研究Kr:F准分子激光对大鼠切牙牙髓的影响。方法 用功率为5W的Kr:F准分子激光照射大鼠切牙1min,百姓凰即刻、第2天、第7天分别处死5只大鼠,作病理切片观察其牙髓变化,并与Nd:YAG激光作比较,结果 Kr：F准分子激光照射后仅出现0-1级的牙髓组织变化。而Nd:YAG激光照射后出现3级变化。结论 Kr:F准分子激光照射牙体硬组织所引起的牙髓反应较小。     

Kr:F准分子激光对釉质表面粘结强度的影响

目的 :探讨在粘接技术中应用Kr:F准分子激光的可能性。方法 :经Kr:F激光照射和酸蚀后的牙齿釉质面 ,分别与窝沟封闭剂粘接 ,比较两组的粘接强度。结果 :Kr:F激光处理组与酸蚀组粘接强度无显著性差异 (p >0 0 5 )。结论 :Kr:F准分子激光可替代化学酸蚀法处理釉质表面 ,并具有操作简便、抗酸力增强等独特的优越性     

Kr:F准分子激光处理釉质与酸蚀釉质粘结强度的比较性研究

目的 探讨Kr:F准分子激光处理釉质表面后对粘接强度的影响。方法 牙齿釉质面分别经Kr:F激光照射或酸蚀后,与窝沟封闭剂粘接,比较两组的粘接强度。结果 Kr:F激光处理组与酸蚀组粘接强度间无显著性差异(P>0.05)。结论 Kr:F准分子激光替代化学酸蚀法处理釉质表面具临床可行性和独特的优越性。     

脉冲Nd:YAG激光促进氟保护漆治疗牙齿敏感症临床观察

目的　观察脉冲Nd :YAG激光促进氟保护漆治疗牙齿敏感症的临床疗效。方法　用计算机程序控制脉冲Nd :YAG激光照射经涂一层氟保护漆的牙齿敏感症患牙 ,并分别与单纯涂一层氟保护漆或单纯脉冲Nd :YAG激光照射的疗效相比较。结果　涂氟保护漆加脉冲Nd :YAG激光照射治疗牙齿敏感症优于单纯涂保护漆或单纯脉冲Nd :YAG激光照射 ,疗效有显著性差异 (P <0 .0 5 )。结论　涂氟保护漆和脉冲Nd :YAG激光照射的联合应用是一种治疗牙齿敏感症较为有效的手段     

Nd: YAG激光对3种树脂水门汀与牙本质粘接强度的影响

目的观察Nd: YAG激光照射前后树脂水门汀-牙本质粘接界面的微观形貌特征,评价Nd: YAG激光对3种树脂水门汀与牙本质间粘接强度的影响。方法选择人离体前磨牙30颗,分为颊、舌两部分,将试件随机分为激光组和对照组。激光组以0.8 W、10 Hz脉冲Nd: YAG激光作用于牙本质表面25 s,联合3种树脂水门汀RelyX ARC、Panavia F和RelyX Unicem充填;对照组直接使用树脂水门汀充填。然后测试剪切强度,在根管显微镜下观察断裂模式并分类。另选人离体前磨牙6颗,按照标准的牙本质粘接面预备后,使用Nd: YAG激光照射3颗牙牙本质表面,并联合充填不同的树脂水门汀,用扫描电镜观察Nd: YAG激光照射前后树脂水门汀-牙本质界面的微观形貌变化。结果
激光照射可以提高自酸蚀树脂水门汀Panavia F和自粘接树脂水门汀RelyX Unicem与牙本质之间的剪切强度（P＜0.05）。激光会降低全酸蚀树脂水门汀RelyX ARC与牙本质间的剪切强度（P＜0.05）。根管显微镜下观察可见：试件断裂大部分发生在树脂水门汀-牙本质界面。扫描电镜观察可见：Nd: YAG激光照射后,全酸蚀亚组和自酸蚀亚组的混合层变薄、树脂突变短且少;自粘接亚组变化不明显,未见树脂突。结论Nd: YAG激光照射后,可提高Panavia F和RelyX Unicem与牙本质的剪切强度,建议临床联合应用。     

Nd：YAG激光照射对根尖倒充填术窝洞封闭性影响的初步研究

目的:探讨Nd:YAG激光照射对根尖倒充填术封闭性的影响.方法:将根管形态相近的52 颗牙齿(前牙35 颗,前磨牙17 颗)随机分成5 组,每组10 颗,其余2 颗为电镜观察标本备用牙.去除牙冠,进行常规根管充填后去除根尖2 mm,用高速球钻将截面预备成碟形洞面.除第1 组外,分别用Nd:YAG激光以不同的时间和不同的方式(涂墨水与不涂墨水)照射洞面,用玻璃离子倒充填后进行微渗漏实验.扫描电镜观察激光处理后窝洞表面结构的改变,分析激光改善窝洞密封性的可能机制.结果:Nd:YAG激光照射组微渗漏程度显著低于对照组(P<0.01),并且涂墨汁组的微渗漏比未涂墨汁组的微渗漏明显减少(P<0.01).激光照射20 s组微渗漏明显低于照射10 s组(P<0.01).结论:Nd:YAG激光照射倒充填窝洞可以增加玻璃离子倒充填窝洞的封闭性.     

Nd：YAG激光对自酸蚀粘结系统和牙本质粘结力的影响

目的探讨Nd：YAG激光对牙本质自酸蚀粘结系统的影响。方法选用因正畸拔除的新鲜前磨牙42颗，随机分为3组，每组14颗；牙面预备暴露牙本质；分别采用Adper^TM Prompt^TM粘结剂＋F2000树脂充填，Nd：YAG激光照射＋Adper^TM Prompt^TM粘结剂＋F2000树脂充填，Adper^TM Prompt^TM粘结剂＋Nd：YAG激光照射＋F2000树脂充填。评价各组树脂与牙本质之间剪切强度。结果Nd：YAG激光照射＋Adper^TM Prompt^TM粘结剂＋F2000树脂充填组的剪切强度明显大于其余2组，其余2组之间剪切强度对比无明显差异。结论先采用脉冲Nd：YAG激光照射后使用Adper^TM Prompt^TM粘结剂组获得最大粘结力。     

Nd:YAG激光辅助治疗深牙周袋患牙的疗效观察

目的：探讨在牙周基础治疗后，应用Nd:YAG激光治疗牙周袋探诊深度仍大于5mm，袋内探诊出血的牙周病患牙的效果。方法：将Nd:YAG激光的光纤深入袋内，沿袋壁上皮，袋底，根面各方向反复照射。结果：治疗此类牙周病患牙30颗，与对照组28颗患牙比较效果更佳，显效率有显著性差异（P＜0．01）。结论：在传统的牙周治疗基础上，应用Nd:YAG激光辅助治疗牙周炎可获得更佳的效果。     

Nd:YAG激光对猴牙牙髓的影响

目的：观察Nd：YAG激光对猴牙牙髓的影响，比较牙面涂布60g／L美蓝和经常规硝酸银脱敏后对激光照射效果的影响情况。方法：以1592、3185、4777mJ／mm^23种能量水平的Nd：YAG激光照射3只猴的30个牙面，用组织病理学方法观察牙髓变化情况。结果：1592mJ／mm^2照射组，不论牙面经何种处理，牙髓反应均与对照组相似，为0级；3185mJ／mm^2照射组，牙髓出现轻度改变；大能量、高频率的4777mJ／mm^2照射则出现广泛性成牙本质细胞变性、坏死。照射面色素的存在增加了激光对牙髓的刺激，氨硝酸银加丁香油酚还原成银沉淀，隔绝了外界刺激对牙本质和牙髓的影响，同样参数的Nd：YAG激光造成的牙髓损害在3组中最小。结论：大能量Nd：YAG激光可造成牙髓组织损伤性反应，照射面经不同的处理可影响Nd：YAG激光的照射效果。     

激光照射加窝沟封闭治疗磨耗引起的牙齿敏感症

目的：观察用激光加窝沟封闭治疗由磨耗引起的牙齿敏感症的临床效果。方法：观察组采用脉冲Nd:YAG激光照射咬He面，然后用光敏固化窝沟封闭剂封闭。对照组单纯用充填法治疗。结果：观察组193个牙齿成功179个，有效8个，失效6个，疗效明显优于对照组。结论：Nd:YAG激光照射后用窝沟封闭剂封闭是一种治疗牙齿敏感症的较好的方法。     

Vapor emissions resulting from Nd:YAG laser interaction with tooth structure

The Neodymium:yttrium aluminum garnet (Nd:YAG) dental laser has been cleared by the United States Food and Drug Administration (FDA) for marketing in intraoral soft tissue treatment. The efficacy and safety of the Nd:YAG laser in the treatment of hard dental tissue as well as the effects of dental irradiation on the pulp and periodontium have been investigated. Odors resulting from laser irradiation have been reported, but the nature and toxicity of associated decomposition vapors is unknown and the health consequences of their inhalation have not yet been studied. OBJECTIVES: The purpose of this in vitro study was to identify vapors emitted during interaction of the Nd:YAG laser with carious human enamel and dentin and sound enamel and dentin coated with organic ink. METHODS: Vapor emissions were collected from prepared sections of extracted human teeth receiving laser irradiation of 100 mJ and 10 Hz for a duration of 1, 10, or 60 s. Emissions were collected by means of charcoal absorption tubes, and subsequently analyzed using a Gas Chromatograph equipped with Mass Selective (GC/MS) and Flame Ionization Detectors to identify the chemical constituents of the vapors. RESULTS: No compounds were identified in Nd:YAG laser-treated caries, enamel and dentin. No volatile vapors were identified from samples of tooth materials exposed to the laser for 1 or 10 s. Camphor was positively identified in the test sample which consisted of India ink-coated dentin and the reference sample of India ink-coated glass beads, both exposed to the laser for 60 s. 2,5-norbornadiene was tentatively identified in these samples. The Threshold Limit Value (TLV) of camphor is 2 ppm with a Lethal Dose Level (LDLo) of 50 mg/kg (human oral), while the TLV and LDLo of 2,5-norbornadiene is unknown. SIGNIFICANCE: Occupational and public health safety measures are discussed in this article. Further research is needed to quantify the compounds produced and to determine their toxicity to patients and to dental care providers.     

Irradiation of human dental tissues with CO2-, Nd:YAG-, and CO2-Nd:YAG combination laser.

Extracted third molars were used to study the effect of Nd:YAG laser irradiation combined with CO2 laser beam on dental hard tissues. The specimens were studied with SEM after lasing and the size of the impact areas and beam penetration into enamel and dentin were planimetrically analyzed. High-energy CO2 laser (e.g. 10 s irradiation with 10 W output energy) penetrated all enamel and dentin. The simultaneous addition of Nd:YAG irradiation to the CO2 beam was found to increase the effect of CO2 laser, while Nd:YAG irradiation alone, used with equivalent energy densities, did not cause any effect on enamel surface. Thus, Nd:YAG laser was found to potentiate statistically significantly the effect of CO2 irradiation, but the morphologic alterations on dental hard tissues, such as crater formation at the beam focus site, appeared to be due to CO2 irradiation alone.     

Irradiation of human dental tissues with CO2-, Nd:YAG-, and CO2-Nd:YAG combination laser

Abstract— Extracted third molars were used to study the effect of Nd:YAG laser irradiation combined with CO₂ laser beam on dental hard tissues. The specimens were studied with SEM after lasing and the size of the impact areas and beam penetration into enamel and dentin were planimetrically analyzed. High-energy CO₂ laser (e.g. 10 s irradiation with 10 W output energy) penetrated all enamel and dentin. The simultaneous addition of Nd:YAG irradiation to the CO₂ beam was found to increase the effect of CO₂ laser, while Nd:YAG irradiation alone, used with equivalent energy densities, did not cause any effect on enamel surface. Thus, Nd:YAG laser was found to potentiate statistically significantly the effect of CO₂ irradiation, but the morphologic alterations on dental hard tissues, such as crater formation at the beam focus site, appeared to be due to CO₂ irradiation alone.     

Nd:YAG激光治疗牙齿感觉过敏症

牙齿感觉过敏症是口腔科的常见病和多发病。应用Nd:YAG激光技术治疗牙齿感觉过敏症已经取得了较好的疗效。有并且在这方面的研究成果正不断出现，成为一个热点，目前主要的研究集中在激光治疗的效果，牙髓的反应和对牙齿硬组织的影响方面，本文就激光治疗牙齿感觉过敏症的机制，疗效和失败的因素作一简要综述。     

The effects of the Nd:Y AG laser on amalgan dental restorative material

The Nd:YAG laser has been marketed as an instrument for use on both hard and soft dental tissues. Its potential for use on hard tissues is limited but it may be the instrument of choice for use in certain soft tissue procedures. The aim of this study was to examine the effects of the Nd:YAG laser on analgam restorations which are frequently placed on tooth surfaces adjacent to the areas of soft tissue which may be subjected to the laser. The amalgam used was Tytin. The laser firing was controlled by a computer and constant repetition rate of 40 Hz was used. Energy per pulse was altered as follows: 30 mJ, 40 mJ, 60 mJ, 80 mJ, 120 mJ and 140 mJ. Exposure times of 0.05 s (2 pulses), 1 s (40 pulses), 2 s (80 pulses), 3 s (120 pulses), 4 s (160 pulses), and 5 s (200 pulses) were used. The width of defect was measured using a measuring microscope with 10x magnification and it was established that the damage threshold lies between 0.125 s (5 pulses) and 0.25 s (10 pulses) for 30 mJ per pulse. Scanning electron microscope observations revealed that the melting of amalgam at exposure times of 5 s actually decreased the size of the observed defect. The data were analysed using a two-way ANOVA statistical test. There was a significant (p<0.001) correlation between the width of the defect and exposure time up to an exposure time of 4 s and the width of defect and the energy per pulse setting. The findings indicate that amalgam restorations are damaged by inadvertent laser exposure and clinicians must take measures to protect such restorations during lasing of soft tissues.     

Effect of CO2, Nd:YAG, and ArF excimer lasers on dentin morphology and pulp chamber temperature: an in vitro study

This study compared the effect of three laser systems: CO2 (10.600 nm), Nd:YAG (1.064 nm), and ArF excimer (193 nm) lasers on dentin hard tissue and on temperature increases of the pulp chamber. Sixty-six third molar teeth were used and randomly divided into three groups. A class I cavity was made to expose the dentin, and the pulp in the pulp chamber was removed via a hole bored in the cervical area. The pulp chamber was subsequently refilled with silicon grease, and a NiCr/NiSi thermocouple was inserted through the hole into the pulp chamber. The dentin surface was then lased for 30 s at the same settings (3 W, 2 mm spot size, 20 pps) with each laser. The average internal temperature increases were as follows: CO2, 37 degrees C; Nd: YAG, 28 degrees C; and ArF excimer, 1 degrees C. Scanning electron microscopy of the dentin in the occlusal cavity revealed extensive carbonization, isolated balls of recrystallized material, and the presence of smear layer at some dentinal tubule orifices for the CO2 and Nd:YAG lased teeth. Smear layer was also observed for the ArF excimer samples; however, they exhibited far less surface cavities than the others and seemed to undergo little morphological change on the dentin.     

Er:YAG激光应用于牙齿漂白的研究进展

Er:YAG激光漂白作为一种新型牙齿漂白方法,与传统漂白技术相比,Er:YAG激光显著提高了漂白效率,具有安全性高、治疗时间短及漂白效果优异等优点,被广泛应用于临床操作.本文就Er:YAG激光漂白技术的作用原理、漂白特点及对牙体组织结构的影响作一综述.现有文献表明,Er:YAG激光对水和羟基磷灰石的高吸收特性使其可以作...     

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??Objective     To investigate the effect of irradiation with Nd??YAG laser on the surface microstructure and temperature change of dental implants in vitro??in order to provide the reference for clinical parameter setting and operation method. Methods    The titanium discs were irradiated by Nd??YAG laser with different parameter setting. The surface microstructure was observed by scanning electron microscope?? and the temperature elevation was measured by thermocouple. The time to reach a 10?? increase in temperature was recorded as well. Results    ??1??Local areas with surface melting on 0.2W ??20 mJ??10 Hz??and significant melting with crackson 1W setting ??100 mJ??10 Hz or 50 mJ??20 Hz?? were observed after Nd??YAG laser irradiation without cooling??while the surface of the titanium disk is still molten with water vapor cooling.??2??The temperature elevation of titanium discs were less than 10?? with low power setting or water cooling conditions of Nd??YAG laser irradiation for 30 seconds. It took 13.8??6.2 and 7.8 seconds??respectively??to reach a 10?? increase threshold in temperature after being irradiated with 0.5 W ??50 mJ??10 Hz??and 1W??100 mJ??10 Hz or 50 mJ??20 Hz??without cooling conditions. Conclusion    Direct and prolonged exposure to Nd:YAG laser leads to microstructure change of implant surface??and may produce a risk of thermal damage to surrounding tissue. The reasonable parameter setting??mobile radiation mode and cooling are suggested.     

Er：YAG激光照射离体牙釉质后表面形态和髓腔温度的观察

目的观察不同能量和时间作用下Er：YAG激光照射人离体牙釉质后表面形态和髓腔温度的变化。方法临床收集24颗离体牙,制备成96个实验样本,按不同处理方法分为A、B两组,分别照射10、20 s,每组再分为6个亚组,选择超短脉冲20 Hz,分别采用1、2、3、4、5、6 W的能量对每个亚组样本的釉质进行照射,用数字式温度计记录髓腔温度的变化,扫描电子显微镜（SEM）下观察样本釉质形态的变化。结果随着照射时间的延长和能量的增加,髓腔温度有上升的趋势;SEM观察A、B两组的釉质形态均有改变,但两组均未发现熔融和碳化现象。结论在Er：YAG激光一定能量的照射下,釉质的形态和髓腔温度产生一定的变化,但是未出现熔融和碳化现象,为临床龋齿的治疗提供了依据。     

不同时间脉冲型Nd:YAG激光照射牙周病牙根面电镜及X射线能谱分析

目的:通过对不同时间脉冲型Nd:YAG激光照射牙周病牙根表面超微结构及牙骨质层主要无机物钙(Ca)、磷(P)含量进行分析,初步探讨临床最佳激光照射时间。方法:临床选择重度牙周病病例,待拔除单根牙共25颗,25个根面,随机分为5组,对照组、激光1组、2组、3组、4组,每组5颗患牙5个根面,另选5颗离体健康阻生牙为健康组。对照组在拔牙前无激光照射,余激光组用脉冲型Nd:YAG激光分别在牙周袋内持续照射15s、30s、60s、90s后,局麻下拔除患牙,处理样品,扫描电子显微镜观察牙根面超微结构,X射线能谱仪对根面牙骨质层Ca、P含量分析,分别计算Ca/P比值,统计学处理。结果:用脉冲型Nd:YAG激光,波长532nm,0.8W输出功率,15～30s为最佳照射时间,即杀菌、玷污层被汽化,又无根面过度损伤;X射线能谱分析激光照射15～30s组,根面牙骨质层Ca/P比值分别与对照组相比,经统计学处理无统计学差异;随激光照射时间延长患牙根面出现熔融碎裂等热伤害现象,形态明显改变,但牙结石仍存。结论:当其他激光参数相对恒定时,正确掌握激光照射时间,是牙科激光技术在牙周病辅助治疗中的重要因素。