Restorative applications

Among the many clinical uses of the latest type of Erbium all tissue lasers is the ability to prepare cavities and cut enamel, dentine and composite. Historically lasers used for these applications have been associated with adverse thermal effects and relatively slow rates of cutting. These problems have now been successfully overcome: by use of an appropriate wavelength (2780-2940nm) the Erbium lasers cut by virtue of the expansive power of water rather than by heat coagulation or carbonisation. By exposing the target tissue to a laser wavelength that activates the water and hydroxyl groups present the tissue is efficiently broken apart. The schematic in the figure illustrates this process which is described technically as ablation. Once exposed to the laser the water and hydroxyl element of the tissue becomes highly agitated such that there is a volumetric increase of 1600x in a fiftieth of a second. The exploding pockets of water drive the tissue apart without any significant thermal damage to the tissues. In fact research shows as opposed to the laser irradiated tissues being heated up there is actually a degree of local cooling, and there is significantly less local heat generated than a conventional turbine. The Erbium lasers also incorporate a water spray which provides additional water for the laser to target in tissues with a low water content such as enamel; this water spray also acts as a coolant so there is no charring or any adverse thermal effects. This is a significant advance over earlier generations of lasers which were associated with considerable heat generation resulting in poor clinical results.