Loganathan Sarathkumar, Santhanakrishnan Soundarapandian, Bathe Ravi, Arunachalam Muthukumaraswamy
Manufacturing Engineering Section, Department of Mechanical Engineering, Indian Institute of Technology Madras.
Manufacturing Engineering Section, Department of Mechanical Engineering, Indian Institute of Technology Madras, .
Lasers Med Sci. 2019 Jun;34(4):693-701. doi: 10.1007/s10103-018-2644-0. Epub 2018 Oct 2.
To predict the laser ablation profile on dental hard tissue which will enable the user to optimize laser parameters so as to carry out the laser treatment with minimal tissue damage. The present study constructs a mathematical model to predict the ablation profile based on Gaussian beam distribution of laser intensity and correlates the model with experimentally obtained ablation parameters (effective Gaussian beam radius, ablation threshold fluence, and effective energy penetration depth). To obtain the ablation parameters, laser ablation experiments were carried out on dental hard tissues using Ti:Sapphire femtosecond laser (800 nm, 100 fs, 10 kHz). The method is further extended to predict the ablation rate and efficiency as well. The profile predicted from the mathematical model is compared with that of experimental results. It is found that the predicted ablation profile agrees well with the experimental profile for both enamel and dentin except a slight deviation at higher fluence for dentin. The calculated ablation rate is comparable to that of experimental results whereas for ablation efficiency appreciable deviation is observed in the case of dentin. The model succinctly predicts the ablation profile, ablation rate, and ablation efficiency which will enable to perform dental surgery at optimized laser processing conditions with high precision thus reducing the tissue damage appreciably. Once the details of lesion are known through proper diagnostic tools, the method enables the user to readily obtain optimum laser parameters. It can be used as a handy reference for dentists to perform damage-free surgery, ensuring quicker healing.
预测牙齿硬组织上的激光消融轮廓，这将使使用者能够优化激光参数，从而以最小的组织损伤进行激光治疗。本研究基于激光强度的高斯光束分布构建了一个数学模型来预测消融轮廓，并将该模型与实验获得的消融参数（有效高斯光束半径、消融阈值通量和有效能量穿透深度）相关联。为了获得消融参数，使用钛宝石飞秒激光（800纳米，100飞秒，10千赫兹）对牙齿硬组织进行了激光消融实验。该方法还进一步扩展以预测消融速率和效率。将数学模型预测的轮廓与实验结果进行比较。结果发现，除了在较高通量下牙本质有轻微偏差外，预测的釉质和牙本质消融轮廓与实验轮廓吻合良好。计算得到的消融速率与实验结果相当，而在牙本质的情况下，观察到消融效率有明显偏差。该模型简洁地预测了消融轮廓、消融速率和消融效率，这将能够在优化的激光加工条件下高精度地进行牙科手术，从而显著减少组织损伤。一旦通过适当的诊断工具了解了病变的详细情况，该方法就能使使用者轻松获得最佳激光参数。它可以作为牙医进行无损伤手术的便捷参考，确保更快愈合。
