Assessment of true vertical root fracture line in endodontically treated teeth using a new subtraction software - A Micro-CT and CBCT study

Developing evidence-based clinical imaging guidelines for the diagnosis of vertically fractured teeth

OBJECTIVES

This study aimed to develop an evidence-based clinical imaging guideline for teeth suspected with vertical root fractures.

METHODS

An adaptation methodology based on the Korean Clinical Imaging Guidelines (K-CIG) was used in the guideline development process. After searching for guidelines using major databases such as Ovid-Medline, Elsevier-Embase, National Guideline Clearinghouse, and Guideline International Network, as well as domestic databases such as KoreaMed, KMbase, and KoMGI, two reviewers analyzed the retrieved articles. The retrieved articles were included in this review using well-established inclusion criteria.

RESULTS

Twenty articles were identified through an online search, of which three were selected for guideline development. Based on these three guidelines, this study developed specific recommendations concerning the optimal imaging modality for diagnosing teeth suspected of vertical root fractures.

CONCLUSIONS

Periapical radiography is the preferred method for assessing teeth with mastication-related pain and suspected vertical root fractures. However, if intraoral radiographs do not provide sufficient information about root fractures, a small FOV CBCT may be considered. However, the use of CBCT in endodontically treated teeth is significantly constrained by the presence of artificial shading.

A retrospective clinical study to compare the ability of cone-beam computed tomographic images and periapical radiographs to reveal cracked teeth, split teeth, and teeth with vertical root fractures

BACKGROUND

This retrospective clinical study aimed to compare the sensitivity of cone-beam computed tomographic (CBCT) images and periapical (PA) radiographs to reveal cracked teeth, split teeth, and teeth with vertical root fractures (VRFs).

METHODS

The authors included 98 patients (98 teeth) diagnosed with a longitudinal tooth fracture (LTF) (cracked tooth, split tooth, VRF) through direct visualization after extraction and with comprehensive clinical and radiographic records. They collected demographic, clinical, and radiographic data. The authors evaluated PA radiographs and CBCT images to identify fractures, fracture lines, and the different patterns of bone loss associated with these teeth. They used the McNemar test to compare PA radiographs and CBCT scans when assessing bone loss. They used the Fisher test to determine statistical relationships between fracture types and demographic, clinical, and radiologic traits. They used an analysis of variance test to compare patient age with fracture types.

RESULTS

CBCT images were significantly more effective (P < .05) in detecting bone loss patterns associated with LTFs than with PA radiographs, with 71% of cases detected via CBCT images compared with 42% via radiographs. Mean age was significantly greater (P < .05) in patients with teeth with VRFs than in patients with split teeth. A significant relationship was observed between the type of fracture and the following variables: root canal treatment (split, VRF, P = .002), deep probing depth (≥ 5 mm) (VRF, P = .026), and having more than 8 teeth extracted from the mouth (VRF, P = .032). Overall, there was a significant difference (P < .001) between the visualization of fracture lines (45% on PA radiographs, 65% on CBCT images).

CONCLUSIONS

CBCT scans provided more information on LTFs than PA radiographs, particularly in the identification of periradicular bone changes.

PRACTICAL IMPLICATIONS

CBCT imaging can assist in making the clinical diagnosis of LTFs through observation of bone loss patterns, providing more information than PA radiographs.

Application of metal artifact reduction algorithm for CBCT diagnosis of temporary anchorage device-tooth root contact: inadequate to reduce false-positive rate

OBJECTIVES

It was recently found that when cone beam computed tomography (CBCT) was used to examine temporary anchorage device (TAD)-tooth root contact, it tends to yield high false-positive (FP) diagnoses. This study investigated whether application of a metal artifact reduction (MAR) algorithm or reducing CBCT scan voxel-size can remediate this problem.

METHODS

18 fresh pig cadaver mandibles underwent TAD placement bilaterally at first molar lingual furcation regions. CBCT scans were taken under varied MAR (absence, presence) and voxel-size (400 µm, 200 µm) settings. Then, TADs were removed and a micro-CT scan (27 µm voxel-size) of the TAD placement site was performed. Three raters, blinded of CBCT scan setting, independently diagnosed whether TADs were in contact with roots. The reliability and accuracy of CBCT diagnoses using micro-CT as the gold-standard were statistically examined.

RESULTS

Generally, CBCT diagnoses had intrarater (Cohen's κ: 0.54-1) and interrater (Fleiss' κ: 0.73-0.81) reliability, within the moderate to excellent range, which did not vary with MAR setting or scan voxel-size. For diagnostic accuracy, FP rate among all raters was mostly in the 15-25% range and did not change with MAR or scan voxel-size settings (McNemar tests, p > 0.05) while false-negative rate was relatively minimal and only occurred to one rater (9%).

CONCLUSIONS

When using CBCT to diagnose possible TAD-root contact, applying a currently available Planmeca MAR algorithm or reducing CBCT scan voxel-size from 400 µm to 200 µm may not decrease FP rate. Further optimization of the MAR algorithm for this purpose may be needed.

Sensitivity and Specificity of MRI versus CBCT to Detect Vertical Root Fractures Using MicroCT as a Reference Standard

INTRODUCTION

Vertical root fracture (VRF) in root-canal-treated teeth frequently results in tooth loss, partly because VRFs are difficult to diagnose and when detected the fracture is often beyond the point of preservation with surgical intervention. Nonionizing magnetic resonance imaging (MRI) has demonstrated the ability to detect small VRFs, but it is unknown how its diagnostic capabilities compare with the current imaging standard for VRF detection, cone-beam computed tomography (CBCT). This investigation aimed to compare the sensitivity and specificity between MRI and CBCT for detecting VRF, using micro-computed tomography (microCT) as a reference.

METHODS

A total of 120 extracted human tooth roots were root canal treated using common techniques, and VRFs were mechanically induced in a proportion. Samples were imaged using MRI, CBCT, and microCT. Axial MRI and CBCT images were examined by 3 board-certified endodontists, who evaluated VRF status (yes/no) and gave a confidence assessment for that decision, from which a receiver operating characteristic curve was generated. Intra- and inter-rater reliability were calculated, sensitivity and specificity, and area under the curve.

RESULTS

Intra-rater reliability was 0.29-0.48 for MRI and 0.30-0.44 for CBCT. Inter-rater reliability for MRI was 0.37 and for CBCT 0.49. Sensitivity was 0.66 (95% confidence interval [CI], 0.53-0.78) and 0.58 (95% CI, 0.45-0.70), and specificity 0.72 (95% CI, 0.58-0.83) and 0.87 (95% CI, 0.75-0.95) for MRI and CBCT, respectively. Area under the curve was 0.74 (95% CI, 0.65-0.83) for MRI and 0.75 (95% CI, 0.66-0.84) for CBCT.

CONCLUSIONS

There was no significant difference in sensitivity or specificity between MRI and CBCT in detecting VRF, despite the early-stage development of MRI.

Diagnostic efficacy of cone-beam computed tomography for detection of vertical root fractures in endodontically treated teeth: a systematic review

BACKGROUND

Vertical root fractures (VRFs) sometimes occur in endodontically treated teeth. They have a difficult diagnosis and a dismal result. The objective of this review was to evaluate the diagnostic performance of cone-beam computed tomography (CBCT) for detecting VRFs in teeth that had undergone endodontic treatment.

METHODS

Literature was reviewed from Web of Science, PubMed, Cochrane Review, SCOPUS, and Embase databases between 2000 and 2022. The searched keywords included "endodontically treated teeth," "cone-beam computed tomography," "CBCT," "tooth fracture," "vertical root fracture," "VRF," "accuracy," "sensitivity," and "specificity." Only articles in the English language were included. The final analysis included 20 papers that satisfied the eligibility requirements.

RESULTS

The overall mean ± SD values (%) for the diagnostic sensitivity and specificity of CBCT for detection of VRFs in endodontically treated teeth in the presence of root-filling materials without an intracanal post were 71.50 ± 22.19 and 75.64 ± 19.41, respectively. The overall mean (SD) value (%) for the sensitivity of CBCT for the detection of VRFs in the presence of root-filling materials and intracanal posts was 72.76 (18.73), while the mean (SD) specificity was 75.44 (18.26). The accuracy of CBCT (mean ± SD) was 78.47 ± 17.19% and 74.02 ± 10.64%, respectively, for teeth without intracanal posts and those with posts.

CONCLUSIONS

Further clinical research is needed to validate the optimum efficiency of CBCT as a diagnostic technique for detecting VRFs in teeth that have had endodontic treatment, given the low sensitivity, significant heterogeneity of studies, and lack of in-vivo studies on the subject.

Micro-computed tomography in preventive and restorative dental research: A review

Purpose

The use of micro-computed tomography (micro-CT) scans in biomedical and dental research is growing rapidly. This study aimed to explore the scientific literature on approaches and applications of micro-CT in restorative dentistry.

Materials and Methods

An electronic search of publications from January 2009 to March 2021 was conducted using ScienceDirect, PubMed, and Google Scholar. The search included only English-language articles. Therefore, only studies that addressed recent advances and the potential uses of micro-CT in restorative and preventive dentistry were selected.

Results

Micro-CT is a tool that enables 3-dimensional imaging on a small scale with very high resolution. In this method, there is no need for sample preparation or slicing. Therefore, it is possible to examine the internal structure of tissue and the internal adaptation of materials to surfaces without destroying them. Due to these advantages, micro-CT has been recommended as a standard imaging tool in dental research for many applications such as tissue engineering, endodontics, restorative dentistry, and research on the mineral density of hard tissues and bone growth. However, the high costs of micro-CT, the time necessary for scanning and reconstruction, computer expertise requirements, and the enormous volume of information are drawbacks.

Conclusion

The potential of micro-CT as an emerging, accurate, non-destructive approach is clear, and the valuable research findings reported in the literature provide an impetus for researchers to perform future studies focusing on employing this method in dental research.

Effect of cone-beam computed tomography metal artefact reduction on incomplete subtle vertical root fractures

Purpose

This study compared the accuracy of detection of incomplete vertical root fractures (VRFs) in filled and unfilled teeth on cone-beam computed tomography images with and without a metal artefact reduction (MAR) algorithm.

Materials and Methods

Forty single-rooted maxillary premolars were selected and, after endodontic instrumentation, were categorized as unfilled teeth without fractures, filled teeth without fractures, unfilled teeth with fractures, or filled teeth with fractures. Each VRF was artificially created and confirmed by operative microscopy. The teeth were randomly arranged, and images were acquired with and without the MAR algorithm. The images were evaluated with OnDemand software (Cybermed Inc., Seoul, Korea). After training, 2 blinded observers each assessed the images for the presence and absence of VRFs 2 times separated by a 1-week interval. P-values<0.05 were considered to indicate significance.

Results

Of the 4 protocols, unfilled teeth analysed with the MAR algorithm had the highest accuracy of incomplete VRF diagnosis (0.65), while unfilled teeth reviewed without MAR were associated with the least accurate diagnosis (0.55). With MAR, an unfilled tooth with an incomplete VRF was 4 times more likely to be identified as having an incomplete VRF than an unfilled tooth without this condition, while without MAR, an unfilled tooth with an incomplete VRF was 2.28 times more likely to be identified as having an incomplete VRF than an unfilled tooth without this condition.

Conclusion

The use of the MAR algorithm increased the diagnostic accuracy in the detection of incomplete VRF on images of unfilled teeth.