上颌第一恒磨牙近中颊根根管宽度和锥度测量分析

目的: 测量分析上颌第一恒磨牙近中颊根根管宽度和锥度,为临床提供参考。方法: 收集50颗上颌第一恒磨牙制作透明牙,然后自近中颊根根尖孔处每隔0.4 mm与根管走行方向垂直连续横切,立体显微镜下放大30倍测量各个切片宽度,计算根尖1/3、中1/3、颈1/3各区段的锥度值。结果: 近中颊根第一根管宽度：根尖最大径（0.38±0.12）mm、最小径（0.34±0.16）mm,根中最大径（0.55±0.26）mm、最小径（0.57±0.12）mm,根颈最大径（1.13±0.34）mm、最小径（0.59±0.18）mm。第二根管宽度：根尖最大径（0.25±0.13）mm、最小径（0.28±0.10）mm,根中最大径（0.36±0.09）mm,最小径（0.17±0.06）mm,根颈最大径（0.79±0.23）mm、最小径（0.23±0.17）mm。近中颊根第一根管锥度：根尖1/3最大径0.03 mm、最小径0.01 mm,中1/3最大径0.06 mm、最小径0.03 mm,冠1/3最大径0.10 mm、最小径0.09 mm。第二根管锥度：根尖1/3最大径0.02、最小径-0.01,中1/3最大径0.06,最小径0.00,冠1/3最大径-0.02、最小径-0.02。结论: MB1具有较大的宽度和锥度,且根尖1/3、中1/3、冠1/3锥度不同,而MB2的宽度和锥度都很小,还会出现倒锥度。

Measurement of the mesiobuccal root canal width and taper of maxillary first molars

PURPOSE: To measure the root canal morphology of the maxillary first molars, to provide reference for clinical work. METHODS: Fifty maxillary first molars were collected and the mesiobuccal root canal taper was observed through production of transparent tooth. The mesiobuccal roots were dissected transversely from their apical foramen vertical to the long axis of the root and 0.4-mm-thick serial sections were made. Each section was observed with a stereomicroscope at 30× magnification to calculate the taper value of apical 1/3, middle third 1/3 and canal orifice 1/3. RESULTS: The width of MB1 root canal: maximum and minimum diameter of root apex was (0.38±0.12) mm and (0.34±0.16) mm, maximum and minimum diameter of root middle was (0.55±0.26) mm and (0.57±0.12) mm, maximum and minimum diameter of root collar was (1.13±0.34) mm and (0.59±0.18) mm. The width of MB2 root canal taper: maximum and minimum diameter of root apex was (0.25±0.13) mm and (0.28±0.10) mm, maximum and minimum diameter of root middle was (0.36±0.09) mm and (0.17±0.06) mm, maximum and minimum diameter of root collar was (0.79±0.23) mm and (0.23±0.17) mm. The taper of MB1 root canal: maximum and minimum diameter of root apical 1/3 was 0.03 and 0.01, maximum and minimum diameter of root middle 1/3 was 0.06 and 0.03, maximum and minimum diameter of root collar 1/3 was 0.10 and 0.09. The taper of MB2 root canal: maximum and minimum diameter of root apical 1/3 was 0.02 and - 0.01, maximum and minimum diameter of root middle 1/3 was 0.06 and 0.00, maximum and minimum diameter of root collar 1/3 was -0.02 and -0.02. CONCLUSIONS: MB1 has a larger width and taper, and root apical 1/3, middle 1/3, collar 1/3 have variable taper; While the width and taper of MB2 are small, and there will be upside down taper.