During 40 years of laser research, a variety of systems have been tested for caries removal and cavity preparation, but up to now only Erbium lasers have achieved clinical importance. Based on a thermomechanical ablation process, these lasers offer not only a high efficiency but also low thermal and mechanical side effects, which are a prerequisite for painless treatments. A number of clinical studies and daily practical applications have proven Erbium lasers to be safe and nearly painless. In the future, lasers are not expected to replace the bur, but will allow a less invasive “smart” dentistry.