Morphology Of Apical Foramen In Permanent Molars In A Guangxi Population

Objective:To investigate the number, shape and diameter of molar apical foramina, and the frequency of accessory foramina. Materials and methods: Eight hundred permanent maxillary and mandibular extracted molars were collected. The roots were stained with methylene blue and the apices were examined with a stereomicroscope (40×) and transferred to a computer to perform the measurements using Phmias software.Results:A total of 2330 foramina was investigated. The incidence of one apical foramen was highest (75%). The most common minor apical foramen shape was oval(71%).The mean minimum diameter of the minor apical foramina ranged from(0.22±0.08) to (0.34±0.13)mm. The mean maximum diameter of the minor apical foramina ranged from (0.29±0.12) to (0.44±0.17)mm. There was significant difference among the different groups in their average apical diameter (P<0.05)The difference between the maximum and minimum diameters of apical foramens was less than or equal to 0.15mm in 83%. There was a high percentage of accessory foramina in mesiobuccal roots of mandibular first molars (10%).Conclusions:The results of this in vitro study indicate that the morphology of molar apical foramina may present highly complex anatomical variations. High variations of the morphology and SDs of minimum diameters obtained in this investigation suggest a relatively high failure percentage when selecting the initial apical file.The study could provide clues for the working width during root canal preparation.