臨床所見と根尖部形態との相関関係に関する研究

抄録

Abstract : The purpose of this study was to examine the correlation ship between clinical findings and apical morpholgy, using 150 human teeth indicated for extraction. After routine clinical and radiographic examinations, specimens were extracted and fixed by 10% formalin solution. 97 out of them were removed of soft tissues by 5% NaOCl to observe root apices with a light and scanning electron microscopes, and remaining 53 specimens were split longitudinally to observe intracanal contents of the apical canal under the same microscopes.

 1. The cement-dentine junctions were located 0.5 mm from the apex in only 52% of vital roots (15/29 roots). In the apical canals of non-vital roots, dentine chips, necrosed pulp tissue, filling materials and bacteria were found, while the vital roots showed vessels, nerves and odontoblatsts.

 2. Of endodontically treated 106 roots (85 teeth), 80 roots (62 teeth) were under-filled. Periapical radiolucencies were found in 34 roots (28 teeth : 43%), and the apical foramina of 16 roots (16 teeth : 20%) were completely colsed by cementum. Of properly-filled 24 roots (21 teeth : 23%), periapical radiolucencies were found in 9 roots (9 teeth : 38%), and the apical foramina were competely closed in 4 roots (4 teeth : 19%). Over-filled 2 roots (2 teeth) showed no periapical radiolucencies and no apical closure with cementum.

 3. Coincidence of root apex and apical foramen was observed in 48% (64/134 roots ; 97 teeth). In other roots, apical foramina were evenly devitated to all directions. Incidence of lateral canals was 26% (35/134 roots, 97 teeth), mostly locating 500～1500 μm from the apex evenly on all root surfaces. The shapes of main apical foramina of 112 roots investigated were classified into oval type (47%), circular type (44%) and others (9%).

 Although the morphology of root apecies was found complicated, it was concluded that the closure of apical foramen with cementum could be induced, even of infected root canal, when the canal was filled 0.5 mm radiographically under from the apex with no remaining debris in the apical canal.