Nd:YAG 激光与根面平整对牙龈成纤维细胞在根面附着的影响

目的 :为探讨Nd :YAG激光照射对牙周病患牙根面的生物相容性影响。方法 :应用体外细胞培养技术 ,观察激光照射等处理根面的不同方式对人牙龈成纤维细胞 (Humangingivalfibroblast,HGF)附着的影响。结果 :Nd :YAG激光照射 根面平整组 ,成纤维细胞接种 2 4h后的附着量明显高于单纯Nd :YAG激光照射组和单纯根面平整组 (P<0 .0 5 )。而单纯激光照射组 (80mj/mm2 )和单纯根面平整组细胞附着量又明显大于未处理组 (P <0 .0 5 )。结论 :用一定能量密度的Nd :YAG激光照射与根面平整术联合应用可提高HGF在患牙根面上的附着量。     

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。     

脉冲Nd:YAG激光不同条件下照射牙根管壁的形态学观察

目的 :观察不同条件下脉冲Nd :YAG激光照射牙根管壁后的清洁程度及管壁牙本质的超微结构改变。方法 :14颗离体人上前牙 ,常规根管预备后 ,分为对照组和激光照射组 ,后者按不同的功率、频率及管壁加墨汁与否 6种设定各 2颗牙分别进行照射 ,然后各组标本扫描电镜下观察并照像记录。结果 :①激光照射各组均较对照组根管壁玷污层减少 ;且随激光功率增大 ,管壁清洁度提高 ,管壁牙本质的超微结构变化增大。其中 2W 2 0 pps组管壁上无玷污层 ,根尖 1/ 3区尚有牙本质熔融、沉积。 3W 2 0pps、4W 2 0 pps组除上述变化外 ,根管壁牙本质熔融更为显著 ,并有程度不同的炭化和裂缝 ;② 2W 15 pps管壁清洁度较 2W 2 0pps组低 ;③ 1W 2 0 pps加墨汁后 ,根管清洁效果显著改善 ,并出现牙本质熔融、小管口封闭。结论 :激光剂量在 2W 2 0pps或在此以上时能有效去除根管壁玷污层 ,达到较理想的清洁效果 ,但只有较大剂量时才能熔融、封闭牙本质小管口 ;加墨汁能在低能量条件下显著增强激光作用效果。     

Nd：YAG激光与根面平整对牙龈成纤维细胞在根面附着的影响

目的：为探讨Ｎｄ：ＹＡＧ激光照射对牙周病患牙根面的生物相容性影响。方法：应用体外细胞培养技术,观察激光照射等处理根面的不同方式对人牙龈成纤维细胞附着的ｄ：ＹＡＧ激光照射＋根面平整组,成纤维细胞接种２４ｈ后的附着量明显高于单纯Ｎｄ：ＹＡＧ激光照射组和单纯根面平整组。而单纯激光照射组和单纯根面平整组细胞附着量又明显大于未处理组。     

Er: YAG激光与Nd: YAG激光在种植体周围炎中的研究进展

种植体周围炎是导致种植修复失败的主要原因之一,其治疗方式多样,但各有其局限性。其中,激光治疗具有高效杀菌、止血止痛、微创等优势,是种植体周围炎的一种有效辅助治疗方法。不同波长激光作用原理不同,Er:YAG激光和Nd:YAG激光联合治疗种植体周围炎的临床效果显著,两者作用范围及作用深度互补,具有较好的应用前景。本文就Er:YAG激光和Nd:YAG激光在种植体周围炎中的研究进展及联合应用进行综述。     

Nd:YAG激光在根管治疗中的研究进展

Nd:YAG激光在根管治疗中较其他激光独具优势和应用潜力,近年来对其在根管治疗中的研究日趋深入和全面。本文着重从Nd:YAC激光对根管治疗的有效性、对根周组织的安全性和对根尖周炎治疗的可靠性三个方面做了综述。     

Nd: YAG激光根管内照射时牙根表面温度的变化

目的 应用Nd: YAG激光进行根管内照射,测量不同能量及频率照射下牙根表面不同部位的温度变化,评价激光根管内消毒过程中牙根邻近组织的安全性。方法 收集30颗单根管恒牙,在牙颈部截去牙冠,截取12 mm牙根,根管预备后制成牙根标本,数字化牙科X线机颊舌向平行照射牙根标本,图像分析软件测量牙根颈部（根颈段）和根部（根尖段）中份的邻面根管壁厚度。将牙根标本根据激光照射能量的不同（1.5、3.0、4.5 W）随机分为3组,每组又根据激光照射频率的不同（15、30 Hz）分为2个亚组。将温度测量仪中的两个热电偶分别固定在牙根标本的根颈段及根尖段中份,用Nd: YAG激光通过光导纤维经根管口导入根管内照射20 s,观察在不同能量及频率照射下牙根表面不同部位的温度变化情况。结果 应用不同功率照射,牙根表面温度上升变化有统计学差异（P<0.01）,功率越大,温度上升越多;在相同功率不同频率照射下,牙根表面温度上升变化无统计学差异（P>0.05）。在相同功率及频率条件下照射,根尖段温度上升较根颈段大,二者有统计学差异（P<0.01）。结论 Nd: YAG激光根管内照射消毒时牙根表面温度上升幅度与照射功率、照射时间及牙根厚度相关,在照射时间20 s功率1.5 W的情况下,牙根及牙周组织是安全的。     

Nd:YAG激光照射根管后的形态学观察

目的：了解感染根管管壁牙本质的病变特点，根管预备及Nd：YAG激光照射对感染根管的作用。方法：选用单根患牙60颗，随机分为5组：对照组（治疗前感染根管）、根管预备组（用手用器械根管预备）、3个激光组（在常规根管预备后，采用3种不同能量参数照射1min），做扫描电镜观察。结果：对照组：感染根管牙本质小管形态不规则，排列紊乱。根管预备组：能去除病变的牙本质层，形成玷污层。50mj 10Hz激光组不能封闭牙本质小管。100mj 10Hz、150mj 10Hz激光照射1min根管壁呈熔融状态，去除了玷污层，牙本质小管封闭和半封闭。结论：激光剂量在100mj 10Hz或在此以上时，能有效清洁根管壁玷污层和封闭牙本质小管。     

Nd: YAG laser irradiation in root canal disinfection

Abstract The purpose of this study was to assess the efficacy of Nd:YAG laser irradiation in disinfecting the root canal system. Seventy-five teeth were uniformly instrumented and sterilized, and their root canals were infected for 60 min with an overnight culture of Enterococcus faecalis in Tryptic Soy Broth. The teeth were divided into 6 groups: 1 - non-infected controls; 2 - infected controls; 3 - infected, laser treated; 4 - infected, laser dummy (dye only); 5 - infected, laser dummy (dye and air-water spray); 6 - infected, NaOCl-treated (reference group). After treatment, the root canals were dried and dentinal shavings removed for a post-treatment culture. Quantitative analysis of bacteria surviving the various treatments were performed, and the bacterial counts for each group were compared. SEM analysis of teeth split longitudinally was used to illustrate the effect of treatment on the smear layer and on surface bacteria. Nd:YAG laser irradiation (group 3) significantly reduced the number of bacteria while NaOCl irrigation (group 6) effectively disinfected the canals.     

Morphology, chemical structure and diffusion processes of root surface after Er:YAG and Nd:YAG laser irradiation

OBJECTIVES: The aim of this in vitro study was to evaluate the effects of Er:YAG and Nd:YAG lasers on morphology, chemical structure and diffusion processes of the root surface. MATERIAL AND METHODS: 60 root samples were irradiated for 1 min each either with 60 mJ/p, 80 mJ/p and 100 mJ/p using Er:YAG laser or with 0.5W, 1.0W and 1.5W using Nd:YAG laser. Scanning electron microscopy (SEM) was used to determine the morphology, infrared (IR) spectroscopy to assess the alterations in chemical structure and one dimensional electron paramagnetic resonance imaging (1-D EPRI) was used to estimate the diffusion coefficients in dental root samples. RESULTS: Er:YAG laser treatment resulted in deep crater formation with exposed dentin. Morphological alterations of root surface after Nd:YAG laser irradiation included cracks, crater formation, meltdown of the root mineral and resolidified porous globules formation. Er:YAG laser failed to alter the intensity of Amide peaks I, II or III. In contrast, treatment with Nd:YAG laser, using the highest power setting of 1.5W, reduced the intensity of Amide peak II and III in comparison to the control. The diffusion coefficients were increased significantly in all Er:YAG and Nd:YAG treated root samples. CONCLUSION: This study demonstrated that Er:YAG laser influences only on morphology and diffusion processes of root surfaces, while Nd:YAG laser also alters the chemical structure of root proteins.     

Nd:YAG激光去除根管内充填材料效果的研究

目的通过测定根管内充填材料的清除率和根管外壁温度的变化,评价不同功率Nd:YAG激光去除根管内充填材料的效果。方法选取临床拔除的40颗单根管离体上颌中切牙,常规镍钛锉根管预备、热牙胶充填根管后,随机均分为A、B、C实验组和D对照组,分别采用1.0,1.5,2.0 W的Nd:YAG激光及Protaper D3再治疗锉去除根管内充填材料,同时测量根管外壁的温度变化。各样本在处理前后分别采用mimics软件将口腔颌面锥形束CT(CBCT)的扫描数据进行处理,计算出实验前根管内充填材料体积、处理后剩余充填材料体积及根管充填材料清除率。结果 A、B、C、D四组根管充填材料清除率分别为80.49%、89.82%、78.09%、21.09%,除A组与C组比较无统计学差异外,其他组间两两比较均有统计学差异(P<0.05);A、B、C、D四组根管外壁温度升高均值分别为5.28、6.48、7.73、0.80℃,A、B、C组均与D组有统计学差异(P<0.05)。结论Nd:YAG激光能够有效去除根管内充填材料,参数设置为频率20 Hz,功率1.5 W,SP模式的Nd:YAG激光根管充填材料清除率高,根管外壁温度较再治疗锉明显升高,但在牙周可耐受范围以内。     

Nd:YAG激光照射对牙周病患牙根面的影响

目的 :研究Nd :YAG激光照射对未处理过的和用超声波或手工器械刮治过的牙周病患牙根面的影响。方法 :选择因严重牙周病而须拔除的单根牙 18颗 ,随机平均分为 6组 ,在临床麻醉下分别先后作如下治疗 :超声波刮治 +激光照射 ;激光照射 +超声波刮治 ;手工器械刮治 +激光照射 ;激光照射 +手工器械刮治 ;超声波刮治 ;手工器械刮治。然后拔除患牙作扫描电镜观察。结果 :单纯用超声波或手工器械刮治过的牙根表面均有明显的涂层 ,而用激光 (2 0pps、2 .0W、3min)照射 ,无论是在刮治前还是刮治后 ,均有助于根面涂层的去除 ,但激光对牙根表面结构有不同程度的影响。结论 :先用Nd :YAG激光照射、再行龈下刮治 ,牙根表面的涂层被清除 ,而结构改变最小。     

Nd：YAG激光在狗牙切髓术中的应用

目的：观察Ｎｄ：ＹＡＧ激光照射狗牙牙髓后的变化，了解Ｎｄ：ＹＡＧ激光照射条件与牙髓反应的关系。方法：肉眼及组织病理学切片法。结果：接受每秒１０个脉冲、输出能量５０ｍＪ照射的牙，术后早期，创伤牙髓的愈合优于对照组；术后２８ｄ及８４ｄ有程度不同的牙本质桥形成，根部牙髓无明显异常，组织学疗效评价均成功。大能量Ｎｄ：ＹＡＧ激光用于切髓术有较强的损伤作用。结论：Ｎｄ：ＹＡＧ具有一定的促进创伤愈合作用     

Effect of Nd:YAG laser irradiation on the apical leakage of obturated root canals: an electrochemical study

AIM: The purpose of this laboratory study was to evaluate the effect of Nd:YAG laser irradiation on the apical leakage of obturated root canals using an electrochemical method. METHODOLOGY: Forty extracted single-rooted teeth were selected and the anatomic crown of each tooth was removed. The specimens were randomly divided into four groups. In group 1, the root canals were prepared with K-files and irradiated with Nd:YAG laser (5 W, 20 Hz) via a 300 microns optical fibre. Then the root canals were obturated with laterally condensed gutta-percha and Pulp Canal Sealer EWT. In group 2, the root canals were treated with the same method as those of group 1 but without laser irradiation. In group 3, the root canals were prepared with ProFiles, laser irradiated and then obturated with vertically condensed gutta-percha and Pulp Canal Sealer EWT. In group 4, the root canals were treated with the same method as those of group 3 but without laser irradiation. The electric resistance between standard and experimental electrodes in the canals was measured over a period of 10 days. RESULTS: At 2 h, groups 1 and 3 irradiated with laser had significantly less apical leakage than group 2 (P < 0.05). After 10 days, group 4 had the highest leakage, followed by groups 2, 1 and 3; the differences between the groups was statistically significant (P < 0.05). CONCLUSIONS: Laser irradiation following root canal preparation reduced apical leakage following root canal obturation.     

Nd：YAG激光对Dyract复合体充填微渗漏的影响

目的　观察Nd :YAG激光照射洞缘牙釉质对复合体Dyract充填微渗漏的影响。方法　新鲜拔除的完整离体牙 5 0颗 ,随机分为实验组 ( 2 6颗 )和对照组 ( 2 4颗 )。在样本牙的颊舌面制备V类洞 ,对照组常规完成Dyract充填 ,实验组用Nd :YAG激光照射洞缘牙釉质后再行Dyract充填。所有样本经冷热循环处理后 ,再进行微渗漏实验。用体视显微镜和SEM观察并拍照记录。结果　激光光蚀组充填体边缘微渗漏比对照组明显低 (P <0 .0 5 )。微渗漏实验与扫描电镜观察结果一致。结论　Nd :YAG激光的光蚀作用有助于增强复合体Dyract与牙体组织的结合 ,改善边缘封闭 ,减少微渗漏 ,有利于充填成功