RESUMO
Because of the anatomical proximity, infection of posterior upper teeth can spread into the maxillary sinus. When confronted with a large persistent periapical lesion on a posterior maxillary root-treated tooth, the practitioner should question the quality of the previous endodontic treatment, evaluate the impact of the potential causes of failure and consider, in the majority of cases, the conservative non-surgical retreatment instead of extraction or periapical surgery of the dental element. This paper reports two cases of healing of extensive periapical bone destruction and of the co-existing sinus pathology of odontogenic origin after non-surgical endodontic retreatment of previously root-treated upper molars. Misconceptions concerning the role of epithelium in the periapical lesion are discussed. Also, emphasis is put on the need of precise radiological diagnosis, pre-operatively as well as post-operatively to ascertain healing and to avoid unnecessary delay in the appropriate management of these patients.
