Analysis on the relationship between Schneiderian membrane thickening in the posterior maxillary region and periapical lesions by cone beam computed tomography.

Objectives: This study aimed to evaluate the thickening of sinus membrane, which is also named Schneiderian membrane (SM), in patients and its relationship with periapical lesions (PAL) in the posterior maxillary region to provide reference for the prevention and treatment of odontogenic maxillary sinusitis.

Methods: A retrospective analysis was conducted on 554 cone beam computed tomography (CBCT) imaging data of maxillary sinuses from 301 patients who met the inclusion criteria to determine the correlation between PAL and SM thickening in the posterior maxillary region. Cases of pathological SM were recorded and classified on the basis of the degree and type of SM thickening.

Effect evaluation of different methods for removal of root canal filling materials.

Objectives: This study aimed to evaluate the efficacy of three methods in root canal retreatment to remove the filling material in the root canals.

Methods: Ninety tooth roots filled by gutta percha or plasticized material (=45, each) were randomly divided into three groups (=15). WaveOne (WaveOne group), 1P drill+WaveOne (1P+WaveOne group), and ultrasound P5 working end ET25+ProTaper Universal (P5+ProTaper Universal group) were used to remove the root canal filling material and prepare for root canal.