短脉宽Er:YAG激光处理对牙本质表层性质及粘接界面的影响  

Effect of short⁃pulsed Er:YAG laser treatment on the property and bonding interface of human dentin surface

作　　者：郑蒲珏 黄文燕 曾素娟[1] 杨雪超[2] Zheng Pujue;Huang Wenyan;Zeng Sujuan;Yang Xuechao(Department of Pedodontics,Guangzhou 510182,China;Department of Endodontics,Affiliated Stomatology Hospital of Guangzhou Medical University,Guangdong Engineering Research Center of Oral Restoration and Reconstruction,Guangzhou Key Labo-ratory of Basic and Applied Research of Oral Regenerative Medicine,Guangzhou 510182,China)

机构地区：[1]广州医科大学附属口腔医院儿童口腔科,广东广州510182 [2]广州医科大学附属口腔医院牙体牙髓科,广东省口腔组织修复与重建工程技术研究中心,广州市口腔再生医学基础与应用研究重点实验室,广东广州510182

出　　处：《广州医科大学学报》2021年第6期50-56,共7页Academic Journal of Guangzhou Medical University

基　　金：广东省科技计划项目(2020A1414010329);广州市荔湾区科技计划项目(201904005)。

摘　　要：目的:探讨短脉冲Er:YAG激光处理后人牙本质表层化学成分、显微硬度的改变及扫描电镜观察粘接界面的改变。方法:以人无龋磨牙为实验样品,制备牙本质圆盘,50μs、300μs短脉宽单脉冲Er:YAG激光分别垂直照射牙本质表面(激光组),球钻组采用金刚砂球钻处理。切削后的牙本质表面涂布自酸蚀粘接剂或分别在不酸蚀、酸蚀15、30 s后涂布全酸蚀粘接剂,扫描电镜观察混合层的表面形貌,筛选更有利于粘接的激光脉宽,进一步测量激光组与球钻组表层钙磷比例,显微硬度仪测量两者表面下层30μm处的硬度。结果:扫描电镜显示,激光组牙本质表面无玷污层,牙本质小管开放,自酸蚀粘接系统或直接涂布全酸蚀粘接系统后的牙本质表面可见均匀的粘接界面,而在磷酸蚀刻后涂布粘接剂时,牙本质表面均可见散在的孔隙,300μs激光组的牙本质表面较50μs激光组有更多孔隙。能谱仪显示,50μs激光组与球钻组间牙本质下层0~30μm范围内钙磷比例差异无统计学意义(P>0.05)。硬度测试显示,50μs激光组牙本质下层30μm处显微硬度高于球钻组(P<0.05)。结论:与传统机械预备方法相比,短脉宽50μs Er:YAG激光处理未改变牙本质的表层性质,相对于磷酸蚀刻后涂布全酸蚀粘接系统,自酸蚀粘接系统或直接涂布全酸蚀粘接系统在与铒激光处理后牙本质结合中提供了更好的粘接性能。Objective:To investigate the changes in chemical composition,microhardness and scanning electron microscope(SEM)morphology of bonding interface of dentin surface after short⁃pulse Er:YAG laser treatment.Methods:Human caries⁃free molars were used as experimental samples and were prepared into dentin discs.The dentin surface was perpendicularly irradiated by single⁃pulse Er:YAG laser with a pulse width of 50 or 300μs(laser treatment groups),or treated with a round emery bur(round bur group).The prepared dentin surface was coated with self⁃etch adhesives,or all⁃in⁃one adhesives without or with 15 and 30 s acid etching.SEM was used to observe the surface morphology of the mixed layer for selection of pulse widths that better favor the bonding.The calcium to phosphorus ratios on the surface of the laser treatment groups and round bur group were further measured.The hardness at 30μm below the surface of both groups was measured by a microhardness tester.Results:The results of SEM showed the Er:YAG laser created a surface free of smear layer and with opened dentinal tubules.An even bonding interface was observed on dentin after coated with self⁃etch adhesives or all⁃in⁃one adhesives without acid etching.A number of interspersing pores were visible on dentin surfaces after coated with all⁃in⁃one adhesives after 15 s or 30 s phosphoric acid etching.More pores were seen in the group treated with 300μs laser compared with 50μs laser.EDX spectroscopy showed that there were no significant difference in the calcium to phosphorus ratio between the laser⁃and bur⁃treated dentin within 0~30μm below the surface(P>0.05).At 30μm below the surface,the microhardness of laser⁃treated dentin was higher than that of bur⁃treated dentin(P<0.05).Conclusion:Compared with the conventional mechanical preparation,short⁃pulsed Er:YAG laser treatment does not alter the surface character of the dentin tissue.Compared with coating with all⁃in⁃one adhesives after phosphate acid etching,use of Er:YAG laser tre

关 键 词：ER:YAG激光 牙本质 粘接 脉冲持续时间 显微硬度 X射线能量色散谱 

分 类 号：R783.1[医药卫生—口腔医学]