Manufacturing Engineering Section, Department of Mechanical Engineering, Indian Institute of Technology, Chennai, India.
Centre for Laser Processing of Materials, International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Hyderabad, India.
J Biomed Mater Res B Appl Biomater. 2021 Apr;109(4):486-495. doi: 10.1002/jbm.b.34717. Epub 2020 Sep 1.
To avoid excessive tissue removal and collateral damage, the high-power density laser is apt for dental surgery also need to have high precision. For high-precision dental surgery with minimal tissue damage, the present work frames a method to predict laser ablation profile based on surface morphology and chemical composition of dentin. The surface morphology and chemical composition were studied on different dentin samples using scanning electron microscope (SEM) and Energy Dispersive X-ray Analysis (EDAX), respectively. The key laser ablation parameters (ω , D , and F ) were determined by laser irradiation study using 800 nm, Ti:Sapphire femtosecond laser at processing condition of 100 fs, 10 kHz and 10 mm/s. The dentin samples show a strong linear correlation between physiochemical characteristics and laser ablation parameters. The surface morphology exhibits a negative linear correlation with threshold fluence, whereas the converse is true for chemical composition. The laser ablation parameters of a random dentin sample are derived from the knowledge of linearity data. From the obtained laser ablation parameters, the complete theoretical ablation profile is constructed and validated with experimental ablation profile. Even though the surface morphology of dentin shows high linearity, the concentration of Ca and P can be used as the most feasible probe in clinical settings. Furthermore, the laser ablation rate and ablation efficiency are predicted by the method to optimize the laser processing condition for any specific teeth. The versatility of the method overcomes the problem of heterogeneity on various teeth and simplifies the method of finding optimal laser processing condition for immaculate laser surgery.
为了避免组织切除过多和产生附带损伤，高功率密度激光非常适合牙科手术，同时也需要具备高精度。为了在最小化组织损伤的情况下进行高精度牙科手术，本工作提出了一种基于牙本质表面形貌和化学成分预测激光烧蚀轮廓的方法。使用扫描电子显微镜 (SEM) 和能量色散 X 射线分析 (EDAX) 分别研究了不同牙本质样本的表面形貌和化学成分。通过使用 800nm、Ti:Sapphire 飞秒激光在 100fs、10kHz 和 10mm/s 的处理条件下进行激光辐照研究，确定了关键的激光烧蚀参数 (ω、D 和 F)。牙本质样本的物理化学特性与激光烧蚀参数之间表现出很强的线性相关性。表面形貌与阈值能流呈负线性相关，而化学成分则相反。随机牙本质样本的激光烧蚀参数是从线性数据的知识中得出的。根据获得的激光烧蚀参数，构建并验证了完整的理论烧蚀轮廓。尽管牙本质的表面形貌表现出很强的线性，但 Ca 和 P 的浓度可以作为临床环境中最可行的探针。此外，还通过该方法预测了激光烧蚀速率和烧蚀效率，以优化任何特定牙齿的激光加工条件。该方法的通用性克服了不同牙齿之间的异质性问题，简化了寻找完美激光手术最佳激光加工条件的方法。
