It was possible for the patients to avoid surgical intervention in a number of complicated periapical endodontic situations by means of Nd:YAG laser-assisted sterilization. A WSR has only very good primary results and the long-term successes are very limited. Once a lesions has healed in the manner explained in this study, in other words, with regeneration of the periapical anatomy, there is a very good long-term prognosis. Laser technology is an instrument whose overall effects represent a decisive improvement in the efficiency of conservative endodontic treatment in fields that were previously outside our sphere of influence.