Er:YAG激光照射对牙本质粘结强度的影响

目的探讨Er:YAG激光照射对牙本质粘结强度的影响。方法选取离体磨牙或前磨牙40颗,随机分为4组:A:酸蚀(35%磷酸)组;B:Er:YAG激光组;C:Er:YAG激光+磷酸酸蚀组;D:空白对照组。每组随机选取2颗制备成3 mm厚的牙本质盘,相应预处理后扫描电镜观察;每组剩余8颗牙制备统一标准粘结面,相应预处理后与树脂粘结测量剪切粘结强度。结果扫描电镜结果显示牙本质面经相应预处理后发生明显改变;统计分析结果显示A组剪切粘结强度最大(16.03±6.56)MPa,其次为C组(13.21±6.08)MPa,两组间差异无统计学意义(P>0.05);D组剪切粘结强度最低(4.52±1.02)MPa,与B组(7.91±4.56)MPa比较差异无统计学意义(P>0.05),与A、C组比较差异有统计学意义(P<0.05)。结论 Er:YAG激光照射联合磷酸酸蚀较单纯Er:YAG激光照射可提高牙本质剪切粘结强度。     

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目的探讨Er:YAG激光与Gluma脱敏剂联合应用对牙本质小管的封闭作用。方法选取2010年3—6月于山西医科大学口腔医院口腔颌面外科因正畸拔除的24颗前磨牙,制成厚约2mm的牙本质片。根据其表面处理方式的不同随机分为4组:对照组、Er:YAG激光组、Gluma脱敏剂组、联合应用组(Er:YAG激光联合Gluma脱敏剂),每组6颗前磨牙。处理后,扫描电镜观察各组牙本质小管形态特征,并测量牙本质小管口的直径和相对面积。结果联合应用组中牙本质小管口的直径和相对面积均明显小于其他各组,且差异有统计学意义(P<0.05)。结论 Gluma和Er:YAG联合应用对牙本质小管的封闭作用优于单独应用Gluma脱敏剂或Er:YAG激光。     

Optimal Er:YAG laser energy for preventing enamel demineralization

OBJECTIVES: The purpose of this study was to identify the optimal laser energy range of Er:YAG laser irradiation for laser-induced caries prevention (LICP). METHODS: Twenty-one human non-carious molars were selected. The teeth were covered with nail varnish, except two 4 mm x 1 mm windows on both the buccal and lingual surfaces. The windows were randomly assigned to groups A, B, C and D, receiving no irradiation, 100, 200 and 300 mJ irradiation, respectively. The pulse width 10 pps (pulse per second) with a 1.0 mm spot size was used. After the laser treatment, each tooth was cut into two halves longitudinally. Then a two-day pH-cycling was performed, with an 18-hour demineralization followed by a 6-hour remineralization. Sections of 120 +/- 20 microm in thickness were obtained from each window. Lesion depth was measured using polarized light microscope coupled with an image analysis software. One-way ANOVA and post-hoc Tukey tests were used for evaluation of treatment effects. RESULTS: The laser treatments of 100 and 200 mJ have demonstrated significant protection of enamel demineralization (p = 0.01 and 0.001, respectively), but not the treatment with 300 mJ (p = 0.106). A smaller lesion depth was observed for the 200 mJ group (97.1 microm) than that of the 100 mJ group (105.6 microm). Compared with the control, a lesion reduction of 32.78 and 26.93% for the 200 mJ group and the 100 mJ group were obtained, respectively. CONCLUSION: Caries prevention may be achieved by using Er:YAG laser treatment if the optimal range of laser parameters for LICP can be employed.     

Er:YAG激光预处理对牙本质-全瓷粘结剪切强度影响的体外研究

目的研究Er:YAG激光预处理牙本质对牙本质与全瓷粘结剪切强度的影响,以期为Er:YAG激光在临床的应用提供参考。方法选择新鲜拔除的完整第三磨牙80颗,根据表面处理方法不同随机分为5组,每组颊面标记为ABCDE,舌面标记为abcde。A/a:Er:YAG激光光照+Optibond Versa/Adper Easy One组;B/b:Er:YAG激光光照+35%磷酸酸蚀+Optibond Solo Plus/Adper Single Bond 2组;C/c:Er:YAG光照能量密度15.73 J/cm~2/31.46 J/cm~2组;D/d:Optibond Versa/Adper Easy One粘结剂组;E/e:35%磷酸酸蚀+Optibond Solo Plus/Adper Single Bond 2组。计算机设计制作牙制作直径3 mm厚2 mm IPS e.max PressⅡ瓷块,常规粘结后制作剪切试件并测剪切粘结强度,电子显微镜下观察断裂类型。SPSS20.0统计学分析软件分别对实验数据进行单因素方差分析和χ~2检验,对实验数据进行两两比较。结果 Er:YAG激光光照与全酸蚀粘结剂联合组剪切强度(23.01±4.41/25.37±3.96)MPa,显著高于其他组,差异有统计学意义(P<0.05)。结论不同厂家的全酸蚀粘结剂联合Er:YAG激光预处理牙面均能够有效提高牙本质与全瓷的粘接强度。     

Compositional analysis of root cementum and dentin after Er:YAG laser irradiation compared with CO2 lased and intact roots using Fourier transformed infrared spectroscopy

The present study examines the dental root after Er:YAG laser irradiation, compared with CO2 lased and non-treated surfaces, using Fourier Transformed Infrared (FTIR) spectroscopy. Freshly extracted human teeth were irradiated by Er:YAG laser at an energy output of 40 mJ/pulse, 10 Hz (0.4 watts), with or without water coolant, and by CO2 laser at an energy output of 0.5 watts in continuous wave mode without coolant. The surfaces were chalky and smooth after irradiation by Er:YAG laser with water coolant, were charred and irregular after irradiation by Er:YAG laser without water coolant, and were completely carbonized after CO2 laser irradiation. The FTIR profiles from samples of the surfaces that were irradiated by Er:YAG laser with water coolant were similar to those from non-treated samples, except for a slight decrease on the OH and amide bands, which are mainly related to organic components. This decrease was observed to be extreme after CO2 laser irradiation and moderate after Er:YAG laser irradiation without coolant. The formation of new bands showing toxic substances was observed to a large extent after CO2 laser irradiation and to a smaller extent after Er:YAG laser irradiation without water coolant. In contrast, no such bands were detected after Er:YAG laser irradiation with water coolant. The present results show that these laser treatments selectively ablated more organic components than inorganic components and that Er:YAG laser irradiation with water coolant did not cause major compositional changes or chemically deleterious changes in either root cementum or dentin.     

Er:YAG激光光子激活光声流技术对根管壁牙本质失水状况及牙根抗压强度的影响

目的探讨PIPS-Er:YAG激光技术(光子激活光声流)治疗后根管壁牙本质失水状况及对牙根抗压强度的影响。方法选取2018年7—9月南京市口腔医院口腔颌面外科门诊拔除的120颗健康正畸减数牙(单根牙)进行离体牙实验,按随机数字表法将其均分为A组(PIPS-Er:YAG激光冲洗组)、B组(注射器冲洗组)、C组(超声荡洗组)和D组(空白对照组,未治疗),比较治疗后各组根管壁牙本质失水状况和治疗前后牙根抗压强度的差异。结果 1) A~D组内各标本根管上、中、下段根管壁牙本质含水量依次递增,但差异无统计学意义(P>0.05);根管壁上段:A、C组低于B、D组(P<0.05),A组略低于C组(P>0.05),B组低于D组(P<0.05);根管壁中段:A组低于B~D组(P<0.05),A组略低于C组(P>0.05),B组低于D组(P<0.05);根管壁下段:A组低于B~D组(P<0.05)、A组略低于C组(P>0.05),B组低于D组(P<0.05)。2) A、B、C组与D组间的抗压强度差异无统计学意义(P>0.05)。结论使用Er:YAG激光PIPS技术能降低根管壁牙本质的含水量,且不会降低牙根的抗压强度,有良好的临床应用前景。     

Nd:YAG激光和Er:YAG激光对根管内粪肠球菌杀灭效果的研究

［摘要］ 目的 观察Nd:YAG激光、Er:YAG激光及两者联用对根管内粪肠球菌的杀灭效果。方法 选取离体牙建立粪肠球菌感染模型,随机分为五组：A组：生理盐水组;B组：1%次氯酸钠溶液组;C组：Nd:YAG激光组;D组：Er:YAG激光组;E组：Nd:YAG激光+Er:YAG激光组。通过细菌培养和扫描电镜观察对比各组的杀菌效果。结果 细菌培养和扫描电镜结果显示：A组杀菌率最低,B组杀菌率最高,E组次高。除C组和D组间杀菌率相近外（P>0.05）,各组间均有统计学差异（P<0.05）。结论 Nd:YAG激光和Er:YAG激光均有一定的根管杀菌效果,两者联用效果更佳,可作为传统消毒方法的补充。     

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。     

Evaluation of selective caries removal in deciduous teeth by a fluorescence feedback-controlled Er:YAG laser in vivo

This study investigated the ability and efficacy of an Er:YAG laser with a fluorescence feedback system for caries removal in deciduous teeth. Seventy-nine carious lesions were excavated using a fluorescence-controlled Er:YAG laser. Endpoint of treatment was defined by emission of fluorescence from the dentine surface below the pre-selected threshold level of 7 units and the subsequent termination of Er:YAG laser radiation. Dentine samples were obtained from the cavity floor, and viable counts of both Streptococcus mutans and Lactobacilli, expressed as colony forming units (log CFU), were evaluated. Preparation time was recorded to assess efficacy of the treatment procedure. S. mutans and/or Lactobacilli were found in 25 out of 79 lesions. Regarding the counts for S. mutans and Lactobacilli, the median log CFU was 0 (min, 0; max, 5.5) and 0 (min, 0; max, 6), respectively, with 2.4% of all samples yielding more than 100 CFU S. mutans and 4.8% yielding more than 100 CFU Lactobacilli. In 8 out of 79 cases, laser excavated cavities were not judged being caries-free using the conventional tactile criterion for assessing caries tissue. Focussing on these teeth, the median log CFU was 0 (min, 0; max, 0.5) for S. mutans and 0 (min, 0; max, 1.6) for Lactobacilli. The mean time for treatment was 2.3 +/- 1.2 min. Of the children, 93.8% rated the laser treatment to be comfortable. The study indicates that the fluorescence feedback-controlled Er:YAG laser might be an appropriate device for caries removal in children using the suggested threshold level of 7 units.     

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目的探讨氧化锆陶瓷表面不同粒径Al2O3颗粒喷砂及牙本质表面Er：YAG激光处理对树脂黏结强度的影响。方法2011年2—10月在山西医科大学口腔医院选取25颗完整人前磨牙,制作50个牙块,暴露牙本质。其中10个牙块表面用35％磷酸酸蚀处理,40个牙块表面用Er：YAG激光蚀刻处理。制作氧化锆陶瓷片50个,20个不做处理,其余30个（每组10个）在0．4MPa压力下分别接受120、80、40μm粒径Al2O3颗粒喷砂20s。试件分为5组（每组10个）：A、B组分别由35％磷酸酸蚀和Er：YAG激光蚀刻的牙块与未做处理的陶瓷片黏结;C、D和E组分别由120、80、40μm粒径Al2O3颗粒喷砂的陶瓷片与Er：YAG激光蚀刻的牙块黏结。各组分别进行黏结强度测试？结果A组的黏结强度[（8．71±0．86）MPa]低于B组[（10．94±0．93）MPa],两组差异有统计学意义（P〈0．05）;C、D和E组的黏结强度[（13．49±1．53）、（13．97±0．83）、（17．11±1．51）MPa]均高于B组,差异有统计学意义（P〈0．01）;C、D组的黏结强度低于E组,差异有统计学意义（P〈0．01）;但C与D组间差异无统计学意义（P〉0．05）。结论氧化锆陶瓷片表面Al2O3颗粒喷砂和牙本质表面Er：YAG激光蚀刻处理可增加氧化锆陶瓷与牙本质间的树脂黏结强度。     

Er：YAG激光在龈下楔状缺损治疗中的临床应用

目的评价Er：YAG激光在治疗龈下楔状缺损中的应用。方法选择有两个洞缘位于龈下1mm～2mm的楔状缺损患牙的患者共20例。对照组以车针预备窝洞,电刀切除牙龈的方法进行牙体预备,实验组以Er：YAG激光预备窝洞并同时切除牙龈的方法完成预备。以VAS评分记录术中不舒适程度,术后随访12个月检查充填体情况。结果试验组VAS平均值为42.3±12.1,对照组VAS平均值为61.1±17.0,两组间差异有显著性（P〈0.01）。术后1周,对照组有1例发生龈退缩。12个月,试验组和对照组分别有2例和3例出现边缘不密合和边缘着色（P〉0.05）。结论激光行龈下楔状缺损牙体预备的方法可以有效减轻术中不适,对充填体质量无副作用。     

Resin bonding to Er : YAG laser-irradiated dentin: combined effects of pre-treatments with citric acid and glutaraldehyde

The purpose of this study was to evaluate the combined effects of citric acid and glutaraldehyde (GA) on the resin bonding to Er: YAG laser-irradiated dentin. Bovine dentin was prepared with 180- to 600-grit SiC paper and then uniformly irradiated with an Er: YAG laser (laser-irradiated group) or immersed in water at 60 degrees C for 15 min (heated group). The samples were then acid-conditioned with 10% citric acid (10-0) or 10% citric acid/3% ferric chloride (10-3) for 15 s and treated with GA for 10 min before bonding to an acrylic rod with 4-META/MMA-TBB resin. These samples were trimmed to prepare miniaturized dumbbell-shaped specimens. After storage in water at 37C for 1 d, the tensile bond strength was measured, and the fractured surface was evaluated using a scanning electron microscope (SEM). In the laser-irradiated and heated groups, the 10-3+GA-treated specimen had higher bond strength than that of 10-0+GA. On the other hand, the tensile bond strength of 10-3 +GA in the non-irradiated group was lower that that of 10-0+GA. In conclusion, the combination of 10-3 and GA for bonding with 4-META/MMA-TBB resin was the most effective for Er: YAG laser-irradiated dentin and heated dentin, but it was not effective for the non-irradiated dentin.     

Er:YAG激光联合生物活性玻璃对封闭牙本质小管效果的研究

目的 研究Er:YAG激光联合生物活性玻璃脱敏剂对牙本质小管的封闭率和抗老化效果,探讨两者联合应用时的最佳顺序.方法 制作45个敏感牙本质模型,将样本随机分成5组,前四组平均每组10颗,应用不同方法进行牙本质脱敏处理:A:Er:YAG激光组;B:生物活性玻璃组;C:Er:YAG激光+生物活性玻璃组;D:生物活性玻璃+E...     

超声波预备根管与Nd：YAG激光照射后根管牙本质的SEM研究

目的：评价超声预备根管及Ｎｄ：ＹＡＧ 激光照射根管壁后,根管内壁的清洁度和管壁牙本质微结构的变化。方法：１２ 个离体成人上前牙分为４ 组制备根管：手用器械、超声根管治疗仪、手用器械＋ Ｎｄ：ＹＡＧ 激光照射、超声波＋ Ｎｄ：ＹＡＧ 激光照射,扫描电镜下观察并照像记录。结果：手用扩锉预备的根管内壁有涂层污染和病理组织残留;超声波预备后根管内壁清洁、涂层消除,牙本质小管口开放;手用器械或超声制备后辅以适当能量激光照射的管内壁牙本质小管口封闭,管间牙本质熔融,并形成空泡状结晶。结论：超声波预备根管可达到理想的清洁效果,但牙本质小管口开放易造成根管术后渗漏。而Ｎｄ：ＹＡＧ 激光照射有利于封闭牙本质小管口,减少根尖孔渗漏,还具有封闭根管内壁死腔的作用。     

Er：YAG激光切除牙根断面的扫描电镜观察

目的对Er：YAG激光切除的牙根断面进行扫描电镜研究,并通过对比超声金刚砂尖以及高速涡轮金刚砂车针切除牙根断面的不同表面状态,为Er：YAG激光应用于临床根尖切除术提供依据。方法将30颗上颌中切牙随机分为3组（Er：YAG激光切除组、超声金刚砂尖切除组、高速涡轮金刚砂车针切除组）,分别使用Er：YAG激光、超声金刚砂尖以及高速涡轮金刚砂车针在距离根尖3 mm处进行牙根切除。使用扫描电镜观察3组牙根断面残屑及玷污层、牙本质小管开放、裂隙以及器械切割痕迹情况。结果Er：YAG激光切除组和超声金刚砂尖切除组牙根断面有少量残屑、玷污层,并有牙本质小管开放;高速涡轮金刚砂车针切除组牙根断面有大量残屑及玷污层,没有牙本质小管开放。高速涡轮金刚砂车针切除组中能看到大量裂隙出现,超声金刚砂尖切除组中可见裂隙出现,而Er:YAG激光切除组中几乎没有裂隙出现。高速涡轮金刚砂车针切除组和超声金刚砂尖切除组牙根断面的表面粗糙并有明显切割痕迹,而Er：YAG激光切除组牙根表面没有切割痕迹,较为平滑。结论Er：YAG激光应用于根尖切除具有一定的优势,其牙根断面组织形态学方面的表现明显优于超声金刚砂尖和高速涡轮金刚砂车针。     

铒激光备洞对牙体与充填体间纳米渗漏和粘结强度的影响

目的评价铒(Er:YAG)激光和高速涡轮手机备洞,对复合树脂充填后牙体与充填体间纳米渗漏和粘结强度的影响。方法选32颗离体前磨牙平均分成两组,对照组用高速涡轮手机备洞;实验组用Er:YAG激光备洞,随后进行光固化复合树脂充填。两组各取8颗,进行纳米渗漏测试,扫描电镜(scanning electron micrographic,SEM)观察渗漏情况。其余样本检测微拉伸强度。使用SPSS 20.0统计软件对各组微拉伸强度进行独立样本t检验。结果在牙体与充填体间,实验组几乎没有纳米渗漏产生,对照组则产生纳米渗漏带。微拉伸强度:对照组(16.10±4.91)MPa,实验组(26.53±3.61)MPa,实验组微拉伸强度大于对照组,两组间差别有统计学意义(P<0.05)。结论与涡轮手机相比,Er:YAG激光备洞的纳米渗漏程度更低,粘结强度更好。     

Er:YAG激光在拆除全瓷修复体中应用的研究进展

全瓷修复体因兼具美观性及高强度在口腔修复中被广泛应用。玻璃陶瓷及氧化锆全瓷材料是临床中应用最为广泛的两种全瓷材料。然而,当全瓷修复体因边缘微渗漏、继发龋等问题需要拆除时,其高强度和高粘接强度极大地增加了拆除难度。近年来,临床医师开始尝试使用Er:YAG激光拆除全瓷修复体。研究表明,Er:YAG激光可以安全高效地应用于玻璃陶瓷修复体的拆除,对于较薄的氧化锆修复体也能发挥作用。全瓷修复体材质及厚度、水门汀类型、激光功率等多种因素均可以影响Er:YAG激光的作用时间。然而,目前研究局限于病例报道及体外研究,缺乏系统的临床研究。Er:YAG激光拆除全瓷修复体的具体作用机制以及激光频率、粘接剂类型、基牙对拆除速度的影响有待进一步研究。     

Er:YAG激光不同能量预处理对自粘结树脂水门汀剪切粘结强度的影响

目的探讨Er:YAG激光不同能量预处理对自粘结树脂水门汀剪切粘结强度的影响。方法按照纳入标准收集人离体磨牙70颗,根据对牙本质表面Er:YAG激光预处理能量的不同随机分为7组:A组(空白对照)、B组(50 m J,10 Hz)、C组(100 m J,10 Hz)、D组(150 m J,10 Hz)、E组(200 m J,10 Hz)、F组(250 m J,10 Hz)、G组(300 m J,10 Hz)。每组10颗牙中随机取2颗切取3 mm厚的牙本质片,按相应分组用不同激光能量预处理后扫描电镜观察;每组剩余8颗牙包埋后,制备一致标准牙本质表面,按相应分组要求预处理后,用自粘结树脂水门汀Rely XTMUnicem将其与Everest ZS氧化锆瓷片粘结,24 h后测试各组剪切粘结强度并进行统计学分析。结果扫描电镜观察显示Er:YAG激光预处理后牙本质表面形态改变明显,变得粗糙不平,牙本质小管开放,无玷污层,管周和管间牙本质脱矿,一定能量范围内呈现较好的粘结表面;剪切粘结强度结果显示Er:YAG激光预处理可增强自粘结树脂水门汀Rely XTMUnicem的剪切粘结强度(P<0.01);C、D、E组的剪切粘结强度与A组有显著性差异(P<0.05)。结论粘结强度与牙本质的粘结表面密切相关,合适能量下的Er:YAG激光预处理能获得较好的牙本质粘结表面,提高自粘结树脂与牙本质和氧化锆瓷的剪切粘结强度。     

Evaluation of micro-tensile bond strength of caries-affected human dentine after three different caries removal techniques

Objective

This study evaluated the effect that different techniques for removing dental caries had on the strength of the microtensile bond to caries-affected human dentine created by three bonding agents.

Materials and methods

Forty-five human molar teeth containing carious lesions were randomly divided into three groups according to the technique that would be used to remove the caries: a conventional bur, an Er:YAG laser or a chemo-mechanical Carisolv^® gel (n = 15). Next, each of the three removal-technique groups was divided into three subgroups according to the bonding agents that would be used: Clearfil^® SE Bond, G-Bond^®, or Adper^® Single Bond 2 (n = 5). Three 1 mm² stick-shaped microtensile specimens from each tooth were prepared with a slow-speed diamond saw sectioning machine fitted with a diamond-rim blade (n = 15 specimens). For each removal technique one dentine sample was analysed using scanning electron microscopy.

Results

There were statistically significant differences in the resulting tensile strength of the bond among the techniques used to remove the caries and there were also statistically significant differences in the strength of the bond among the adhesive systems used. The etch-and-rinse adhesive system was the most affected by the technique used to remove the caries; of the three techniques tested, the chemo-mechanical removal technique worked best with the two-step self etch adhesive system.

Conclusion

The bond strength values of the etch-and-rinse adhesive system were affected by the caries removal techniques used in the present study. However, in the one- and two-step self etch adhesive systems, bond strength values were not affected by the caries removal techniques applied. While a chemo-mechanical caries removal technique, similar to Carisolv^®, may be suggested with self etch adhesive systems, in caries removal techniques with laser, etch-and-rinse systems might be preferred.

Clinical significance

Caries removal methods may lead to differences in the characteristics of dentine surface. Dentine ultra structure generally affects the bonding of adhesive materials commonly used in restorative dentistry. Whereas etch-and-rinse system, like the ones used in the present study, are affected by these changes, the self etch systems are not affected. Hence, clinicians may opt for caries removal methods and systems appropriate for each patient and practice.