Novel biomedical applications of lasers: dermatology, gynecology, and stomatology

Water is an important constituent of all soft and hard human tissues. For this reason, the Er:YAG laser is of a particular interest for tissue ablation since its wavelength coincides with the major absorption peak of the water molecule. By controlling the temporal structure of Er:YAG pulses it is possible to control the laser-tissue interaction from “cold” to coagulative ablation, thus optimizing the laser either for skin resurfacing or for precise and painless cutting of teeth. The high absorption of the Er:YAG in irrigation fluids has been utilized also for photo-acoustically induced cleaning and disinfection of dental root canals.
On the other hand, the wavelength of the Nd:YAG laser lies in the skin’s optical window and is thus suitable for transcutaneous delivery of laser energy deep into the adipose tissue. This characteristic has been explored for a novel “fat reduction” procedure offering a less invasive alternative to surgical liposuction.
Recently, it was discovered that the extremely short absorption depth of the Er:YAG laser in soft tissues can be utilized also to create extremely short and intense heat shock pulses within the superficial tissue layer without causing irreversible thermal damage or ablation of the tissue. The discovery has led to the development of novel minimally invasive methods in various medical areas, including for treating vaginal atrophy, urinary incontinence or snoring, thus in many cases replacing much more aggressive and risky standard surgical procedures.