title: [Etiology and treatment of severe periapical periodontitis following pulpectomy and root canal therapy--studies of clinical cases].
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D010485:Periapical Periodontitis / Q000209:etiology* / Q000628:therapy; D011670:Pulpectomy / Q000009:adverse effects*; D012390:Root Canal Therapy