Internal root resorption is infrequent in permanent dentition, most cases are observed in anterior teeth, its etiology is not entirely clear, which is why the treatment for this type of lesion is endodontics. We present the case of a 38-year-old female patient, without relevant medical history, referred for evaluation of tooth 2.2 with a poor prognosis. Diagnosis Acute apical abscess, tooth with internal resorption and apical lesion. Endodontics are performed with bioceramic cements and the application of a 808 nm wavelength therapeutic laser, with specific parameters to accelerate bone tissue repair. Low-level laser photobiomodulation therapy appears to be useful as an adjunct in the bone repair process in endodontically treated teeth with apical lesion and internal resorption.