This study aims to analyze the improvement of postoperative pain and Oral Health-Related Quality of Life (OHRQoL) following endodontic emergency treatment, as well as the contributing factors affecting the change including age, gender, tooth type, dental arch, pulpal status, percussion pain, radiographic evidence of periapical lesions, type of emergency treatment (pulpotomy / partial pulpectomy / complete pulpectomy), and occlusal adjustment.