Diagnostic Accuracy of CBCT for Detection of Second Canal of Permanent Teeth: A Systematic Review and Meta-Analysis

Abstract

Introduction: Missed canal is one of the common reasons for nonsurgical endodontic retreatments. The missed canals were frequently associated with periapical pathology. The aim of this systematic review was to find the diagnostic accuracy of CBCT for detection of the second canal of the root canal system of permanent teeth.

Materials and methods: The articles were selected from seven electronic databases according to selection criteria. All eligible studies were judged by the reviewers. The selected studies were checked with the QUADAS-2 tool for risk of bias and applicability concerns. Finally, 12 studies were selected for qualitative and quantitative analyses. The summary estimates of sensitivities and specificities and SROC curves were calculated and drawn by RevMan 5.3 and MetaDTA software.

Results: Summary estimates of CBCT for detection of second canal anatomy in permanent teeth were 94% sensitivity and 93.1% specificity. 96.6% sensitivity of MB2 was followed by 88.8% sensitivity of maxillary and mandibular premolars and 81% that of mandibular molars. The specificity of 97.6% for premolars was trialed by 85% specificity of mandibular molars and MB2. For permanent mandibular canines, 67% sensitivity and 100% specificity were estimated. CBCT showed more agreement with detecting the second canal with micro-CT, estimating 100% sensitivity and 95.6% specificity. The highest prevalence of the second canal comprised the highest sensitivity of 99.1% and lowest specificity of 77.5%. After the exclusion of case-control studies, a 3% drop of sensitivity from the summary estimate was observed. Multiple spectrum of the second canal had 8.6% higher sensitivity and 4.4% lower specificity than single spectrum.

Conclusion: CBCT is informative for detecting the second canal. Clinicians should keep in mind that the accuracy can vary in different types of teeth, with the prevalence of second canal across different populations, and with the spectrum of second canal anatomy in spite of the reviewers having postulated overestimation of the findings.

Figure 1

PRISMA flow diagram of the included and excluded studies.

Figure 2

Risk of bias and applicability concerns graph for the included studies (review authors' judgments about each domain presented as percentages across included studies).

Figure 3

Risk of bias and applicability concerns summary for the included studies.

Figure 4

Summary receiver operating characteristic (SROC) curve of CBCT for detection of second canal in permanent teeth.

Figure 5

Summary receiver operating characteristic (SROC) curve of CBCT for detection of different types of permanent teeth except for mandibular canines.

Figure 6

Forest plot of CBCT for detection of second canal in different types of permanent teeth.

Figure 7

Crosshairs plot of CBCT for detection of second canal according to types of reference standard.

Figure 8

Summary receiver operating characteristic (SROC) curve of CBCT for detection of second canal according to level of prevalence.

Figure 9

Summary receiver operating characteristic (SROC) curve of CBCT for detection of second canal after exclusion of diagnostic case-control studies (^∗red-filled arrow indicates the drop of sensitivity).

Figure 10

Summary receiver operating characteristic (SROC) curves of CBCT for detection of single spectrum and multiple spectrum of second canal anatomy of permanent teeth (^∗red-filled arrows indicate the drop and uphill of sensitivity). (a) Single spectrum of second canal. (b) Multiple spectrum of second canal.

Figure 11

Forest plot of CBCT for detection of single and multiple spectrum of second canal anatomy in permanent teeth.

Figure 12

Unadjusted and adjusted funnel plots by trim-and-fill method (6 opened circles in second figure represent filled studies). (a) Unadjusted funnel plot. (b) Adjusted funnel plot by the trim-and-fill method.