The basic laser ablation processes of dental hard tissue will be reviewed. Pulse lengths covered in this presentation range from some femto seconds to the cw-mode, wavelengths from the ultraviolet to the infrared spectral domain. The underlying tissue removal mechanisms extend from surface evaporation, to photochemical processes, to mediated explosive ablation, to plasma processes. The most effective mechanism is the explosive process. Highly controlled tissue removal at low ablation rate can be obtained using plasma mediated ablation. Good tissue specivity characterizes the ablation in the near UV region of the spectrum.