Just after the introduction of the first laser by Maiman, in 1960, there has been a very fast evolution of this new technology characterized by the constant progression about techniques and applications, devices ever more efficient, smaller and cheaper, and the introduction of ever-new wavelengths. One interesting application of this new technology was the possibility to weld many kinds of metals and, in industrial fields, this procedure spread in a very short time. Laser welding was firstly introduced in jewellery during years 70 and, just after, it was successfully used also by dental technicians (Maddox, 1970). Initially, CO2 and Nd:YAG were used but, finally, the second one rapidly conquered the market due to the results obtained (Shinoda et al, 1991Yamagishi et al, 1993) Laser welding, in fact, gives a greater number of advantages than traditional welding. First of all laser device saves time in commercial laboratory because welding is completely done directly on the master cast. Inaccuracies of assembly caused by transfers from the master cast along with investment are reduced. (Berg et al, 1995) Then, the heat source is a concentrated and high power light beam able to minimize distortion problems on the prosthetic pieces. (Santos et al, 2003) Another interesting aspect is the possibility to weld very close to acrylic resin or ceramic parts without physical (cracking) or colour damage (Bertrand et al, 1995)): this means to save time and money during the restoration of broken prosthetics or orthodontics appliances because of the possibility to avoid the remaking of the non-metallic portions. This welding technique may be used on every kind of metal but the property to be very active on titanium makes it very interesting and specific for the prosthetics over endosseous implants. (Walter et al, 1999) Many laboratory tests have demonstrated laser welding joints have a high reproducible strength for all metals, consistent with that of the substrate alloy. (Bertrand et al, 2004) All these advantages gave to this procedure a great diffusion in the technician laboratories and stimulated the companies to put in the market more and more upgraded appliances. Some aspects, such great dimensions, high costs and delivery system by fixed lenses today still characterize these machines, strictly limiting their use only to technician laboratories. Moreover, the management of this appliance is very difficult, due to the number of the parameters involved and the factors related to the welding process. For these reasons, it 1