Impact of the use of high-power 810-nm diode laser as monotherapy on the clinical and tomographic success of the treatment of teeth with periapical lesions: an observational clinical study.

Objectives: The aim of this study was to demonstrate the impact of a high-power 810-nm diode laser as monotherapy on the clinical and tomographic success of treating teeth with periapical lesions, through a series of 31 cases. Methods: Teeth with apical lesions underwent endodontic treatment in which a high-power 810-nm diode laser with saline solution was used as monotherapy for disinfection. This type of therapy aimed to replace the traditional irrigation protocol with sodium hypochlorite. This research is the first to assess the clinical success of this alternative treatment, along with tomographic evaluations conducted over periods ranging from 2 to 7 years, analyzed using the periapical index based on cone-beam computed tomography (CBCTPAI). All cases were performed by a single clinician following the same laser protocol, which involved using 1 W of continuous power and four cycles of 20 seconds of laser activation. Results: All teeth showed no clinical symptoms upon follow-up examination. However, the tomographic evaluation revealed that the success rates for teeth receiving primary treatment were 60% and 80% according to strict and loose criteria, respectively. For teeth requiring retreatment, the success rates were 12.5% and 37.5% using strict and loose criteria, respectively. Conclusions: The teeth with apical lesions that underwent primary treatment did not present clinical symptoms, but they showed a moderate success rate on tomographic evaluation. However, despite lacking clinical symptoms, teeth with apical lesions that required retreatment had a very low success rate on tomographic evaluation.