Peiris H R D, Pitakotuwage T N, Takahashi M, Sasaki K, Kanazawa E
Department of Anatomy and Physical Anthropology, Nihon University Graduate School of Dentistry at Matsudo, Matsudo, Japan.
Int Endod J. 2008 Oct;41(10):828-35. doi: 10.1111/j.1365-2591.2008.01428.x.
To investigate differences in the root canal morphology of permanent mandibular molar teeth at various ages.
Four hundred and eighty permanent mandibular first and second molars were examined. First and second molars were divided into six and five groups, respectively, according to the age of the patient at the time of extraction. Root canal morphology was studied using a clearing technique. The canal morphology of the mesial root was classified into three stages depending on its developmental pattern. When the root canal system was completely differentiated, the canal classification and the number of lateral canals and inter-canal communications were recorded. Vertucci's classification was taken as the main reference. Canal morphology was compared amongst age groups.
In both first and second molars, developmental stages of canal morphology amongst age groups were significantly different (P < 0.0001). The prevalence of inter-canal communications was highly significantly different in the first (P < 0.0001) and less significant in the second molar (P < 0.05). After completion of the canal differentiation, the mesial roots of first molars had type IV and II canal forms. The majority of the mesial roots of second molars had type I and III canals. C-shaped canals were found in 3% of second molars.
Mesial roots of first and second molars mostly had one large canal until 11 and 15 years of age, respectively. In both molars, the canal system was completely defined at 30-40 years. The prevalence of inter-canal communications was low at young and old ages but high at intermediate ages.
研究不同年龄阶段恒下颌磨牙的根管形态差异。
检查了480颗恒下颌第一和第二磨牙。第一和第二磨牙根据患者拔牙时的年龄分别分为六组和五组。采用透明技术研究根管形态。根据近中根的发育模式，将其根管形态分为三个阶段。当根管系统完全分化时，记录根管分类、侧支根管数量和根管间交通情况。以韦尔图奇分类法作为主要参考。比较各年龄组之间的根管形态。
在第一和第二磨牙中，各年龄组根管形态的发育阶段均有显著差异（P < 0.0001）。第一磨牙根管间交通的发生率差异极显著（P < 0.0001），第二磨牙差异较小（P < 0.05）。根管分化完成后，第一磨牙的近中根有IV型和II型根管形态。第二磨牙的近中根多数为I型和III型根管。在3%的第二磨牙中发现了C型根管。
第一和第二磨牙的近中根在11岁和15岁之前大多有一条大根管。在这两种磨牙中，根管系统在30 - 40岁时完全确定。根管间交通的发生率在年轻和老年时较低，而在中年时较高。
