Micro-CT evaluation of apical delta morphologies in human teeth

Abstract

The apical delta is an intricate system within the root canal and incompletely debridement may affect the long-term prognosis of root canal therapy. The aim of the present study is to investigate the morphologic features of apical deltas in human teeth with micro-computed tomography (micro-CT) using a centreline-fitting algorithm. One hundred and thirty-six apical deltas were detected in 1400 teeth. Molars had more apical deltas (15.8%) than anterior teeth (6.3%). In maxillary molars, the mesiobuccal root had a significantly higher prevalence of apical delta than the palatal root or the distobuccal root. The median vertical distance of the apical delta was 1.87 mm with 13% more than 3 mm. The median diameter and length of the apical delta branches were 132.3 and 934.5 μm. Apical delta branches were not straight with cross-sectional shapes being non-circular. These morphological features of apical delta may complicate debridement of the infected root canal system.

Quantitative Evaluation of Apical Delta Morphologies in Mesial Roots of Mandibular First Molar Teeth: A Micro-CT Study

“…In a recent micro-CT study, Gao et al evaluated the incidence of apical deltas according to the different tooth types and reported that mandibular molar teeth commonly present these ramifications. 13 The results of the present study are in accordance with the report of Gao et al despite the different study populations. The present study only evaluated the mesial roots of mandibular molar since these roots are considered to have the most complex internal anatomies.…”

“…10 The increase in the prevalence rates might reflect the superiority of micro-CT techniques over the clearing method to detect fine anatomical variations. The mean number of apical delta ramifications per root was 4.45, which was similar to the results reported by Gao et al 13 The root canal configuration of most of the specimens presenting with apical deltas could not be classified according to the Vertucci classification (72.72%).…”

“…On the other hand Gao et al reported significantly similar incidence rates between the mesial and distal roots of mandibular molars. 13 In their study, Çalışkan et al reported the prevalence of apical deltas in mesial roots of mandibular first molars as 8.47%. 10 The increase in the prevalence rates might reflect the superiority of micro-CT techniques over the clearing method to detect fine anatomical variations.…”

“…13 Therefore, micro-CT was utilized in this study because it provided the exact and precise configuration and number of apical delta ramifications. Micro-CT is a non-destructive technology that allows three-dimensional reconstruction and quantitative analysis of internal root canal anatomy in such detail, which could not be obtained from clearing, sectioning or digital radiography techniques.…”

“…11,12 Micro-CT also allowed researchers to make quantitative analysis to reveal the actual root canal anatomy and ramifications. 13 The aim of the present study was to determine the frequency of apical deltas and quantitatively analyze the morphologic features of apical deltas in mesial roots of mandibular first molar teeth.…”