High tech dentistry now involves the routine use of lasers in general dental practice for various procedures once thought only possible with the conventional dental drill or scalpel. In 1990, the first dental laser, the dLase 300 (American Dental Lasers, Corpus Christi,TX 78405 USA), was introduced to the profession. There are now many different types of laser used in dentistry using a variety of wavelengths. Each laser wavelength is absorbed differently by soft and hard tissues and the efficiency of the laser has been determined by the ability of the tissue to absorb or reflect that wavelength. This and the following article hope to give a broad overview of dental lasers and their clinical uses. This article gives an overview of the relevant laser physics and highlights the laser-tissue interactions.