Prediction of femtosecond laser ablation profile on human teeth

Abstract

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.

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