Anyone read this yet? I haven’t gotten around to it yet.

Heat diffusion and debris screening in Er:YAG laser ablation of hard

biological tissues

B. Majaron1, D. ?Su?ster?ci?c2, M. Luka?c1, U. Skaleri?c2, N. Fund

A double-threshold behavior of the ablation efficiency was observed in human dentin and enamel with Er:YAG laser pulses longer than approximately 300 ms and 100 ms. Its origin can be explained by a simple analytical model of interplay between heat diffusion and the ablation front dynamics. It predicts the fluence values at which the reduced ablation efficiency and excessive thermal damage can, in general, beexpected, depending on the laser pulse duration and the tissue properties. In the repetitive ablation of dry dental tissues, the reduction of ablation efficiency is amplified by tissue desiccation, and probably masked by other heat-induced transformations, such as carbonization of dentin. In the absence of heat diffusion, the ablation efficiency is found to depend directly on the laser pulse duration. The effect, which is attributed to the back influence of the ablation velocity on the debris screening process, is modeled analytically with satisfactory results..