能量密度和扫描速度对飞秒激光牙体切削效率的影响  

Effects of fluence and scanning velocity on the ablation efficiency of dentin and enamel by femtosecond laser

作　　者：陈虎[1] 刘晶[1] 葛文琦[2] 孙玉春[1] 王勇[1] 吕培军[1] 

机构地区：[1]北京大学口腔医学院·口腔医院口腔医学计算机应用中心口腔数字化医疗技术和材料国家工程实验室卫生部口腔医学计算机应用工程技术研究中心,100081 [2]中国科学院光电研究院

出　　处：《中华口腔医学杂志》2013年第5期299-302,共4页Chinese Journal of Stomatology

基　　金：基金项目：国家科技支撑计划（2012BA107804）;北京市科技新星计划（2008A009）

摘　　要：目的探索不同能量密度和扫描速度的飞秒激光切削牙釉质和牙本质的效率，以期为飞秒激光的临床应用提供参考。方法将离体牙（中切牙和第一磨牙各2颗）沿轴面纵切制成厚1mm的牙釉质和牙本质试件各2个，选取36个牙釉质区域和48个牙本质区域作为实验区域。使用波长800nm、脉宽30fs、重复频率1000Hz的飞秒激光器，聚焦直径25μm，激光扫描速度设置为10和20mm／s。通过调节激光功率将能量密度设置为1．33、1．77、2．21、4．42、8．85、17．69J／cm2切削牙釉质，以及设置为0．44、0．66、0．88、1．33、1．77、2．21、4．42、6．63J／cm2。切削牙本质。用激光三维形貌测量显微镜测量切削体积，计算牙釉质、牙本质的切削效率。结果能量密度为8．85J／cm2、扫描速度为20mm／s时，飞秒激光牙釉质切削效率最大，为18．703×10^-3mm3／J；能量密度为2．21J／cm2、扫描速度为20mm／s时牙本质切削效率最大，为223．458×10^-3mm3／J。结论飞秒激光的能量密度和扫描速度对切削效率有明显的影响，选择适宜的能量密度和扫描速度可提高飞秒激光的牙本质和牙釉质切削效率。Objective To measure the effect of laser fluence and scanning velocity on ablation efficiency of enamel and dentin. Methods Two extracted human incisors and two molars were cut transversely along the axial plane with a diamond saw to obtain dentin and enamel slices with thickness of about 1 mm. Samples were fixed on a motorized translation stage, the linear reciprocating movement in the plane perpendicular to the direction of laser incident was programmed by the controller, and the laser focused on the tooth surface, then 36 ablation lines on enamel and 48 ablation lines on dentin were produced. A femtosecond laser system with wavelength of 800 nm, pulse width 30 fs, repetition frequency 1000 Hz was used, and the diameter of the focused spot was approximately 25 μm. A group of different fluence （ 1.33, 1.77, 2. 21, 4. 42, 8.85, 17.69 J/cm2 for enamel and 0. 44, 0. 66, 0. 88, 1.33, 1.77, 2. 21, 4.42, 6.63 J/cm2 for dentin） and two scanning velocity （10 mm/s and 20 mm/s） were tested. Confocal laser scanning microscope was used to measure the ablation volume. Ablation efficiency for enamel and dentin was then calculated. Results Under the fluence of 8.85 J/cm2 there was the highest ablation efficiency for enamel, 18. 703 ×10^-3mm3/j （20 mm/s）, and the highest ablation efficiency for dentin was found under the fluence of 2. 21 J/cm2, ie. 223.458×10^-3mm3/j （20 mm/s）. Conclusions Fluence and scanning speed of this femtosecond laser can affect ablation efficiency for both enamel and dentin, and this suggests that with appropriate choice of fluence and scanning speed we can improve the ablation efficiency for enamel and dentin.

关 键 词：激光 牙釉质 牙本质 效率 

分 类 号：R783[医药卫生—口腔医学]