上颌第一磨牙根管弯曲度的实验研究

目的:分析上颌第一磨牙根管弯曲位置、方向及弯曲度。方法:收集80个上颌第一磨牙,在根管中分别插入15#-20#扩大针,拍摄近远中向和颊舌向X线片,用Photoshop6.0软件测量根管弯曲位置、方向和弯曲度。结果:上颌第一磨牙腭侧根管通畅、较直。远中颊侧根管80%在近远中方向、45%在颊舌方向有>5°的明显弯曲,弯曲位置多位于根中1/3,且近远中向弯曲度明显大于颊舌向(P<0.05)。近中颊根颊侧根管在近远中方向、颊舌方向分别有82.5%、77.5%出现>5°的明显弯曲。两个方向上的弯曲度无明显差异(P>0.05)。35%的标本探通了近颊根舌侧根管,其在近远中向、颊舌向出现明显弯曲的比例达91%和83%。结论:上颌第一磨牙四个根管在近远中向、颊舌方向均有不同程度的弯曲,其第二弯曲出现的情况也各不相同。

Study of canal curvatures in the roots of first maxillary molars

Objective:To analyse the root canal curvature frequency,position,direction and degree of the maxillary first molars.Method:80 randomly selected first maxillary molars were used in the study.Radiograph of teeth in buccolingual and mesiodistal directions with 15-20# reamers in root canals was calculated and analysed by Photoshop 6.0 .Result:Lingual root canals of first maxillary molars showed no curvatures.Distobuccal root canals were 80% curved in mesiodistal direction and 45% in buccolingual direction.The curvature was in the middle 1/3 region and the curvature degree in mesiodistal direction was significant different with that in buccolingual direction(P<0.05).MB1 root canals were 82.5% curve in mesiodistal direction,and 77.5% in buccolingual direction .There is no difference of curvature degree in the two directions.MB2 root canals were found by the rate of 35% and were 91% curved in mesiodistal direction and 83% in buccolingual direction.Conclusion:Majority of the four root canals of first maxillary molars have curvatures at various degree in mesiodistal and buccolingual directions,The second curvatures of them were also different .