In vivo detection of vertical root fractures in endodontically treated teeth: Accuracy of cone-beam computed tomography and assessment of potential predictor variables

Abstract

Background: This study aimed: (a) to determine the diagnostic performance of cone-beam computed tomography (CBCT) for detection of vertical root fractures (VRFs); (b) to evaluate the predictive value of diagnostic criteria regarding the definition of VRFs; and (c) to examine the robustness of the association of patient-, tooth-, and treatment-related variables with VRFs.

Material and methods: 130 root-filled teeth with signs/symptoms of VRFs underwent clinical and CBCT assessments. Definite diagnosis of VRF was confirmed by endodontic microsurgical (EMS) exploration. Determination of diagnostic performance of CBCT was based on standard algorithms derived from two-way contingency table analysis. Predictive value of diagnostic criteria and the association between predictor variables with VRFs were analyzed using logistic regression models.

Results: VRFs were detected during EMS in 50% of the teeth. Based on the finding of fracture lines on CBCT scans, sensitivity, specificity, and accuracy were 86.2%, 13.8%, and 50%, respectively. Teeth having more than three diagnostic criteria present had significant higher odds for VRF diagnosis. After logistic regression analysis, parafunctional habits, one-canal roots, excessive root canal enlargement, and absence of intra-radicular posts remained as robust predictor variables of VRFs.

Conclusions: Although the sensitivity of CBCT for VRFs detection is high, the risk of false-positive results related to its low specificity makes that all suspected cases must be confirmed by surgical exploration. VRFs cannot be reliably diagnosed by isolated clinical signs/symptoms; instead those teeth possessing more than three diagnostic criteria might be considered practically pathognomonic. The parafunctional habits, one-canal roots, excessive root canal enlargement, and the absence of intra-radicular posts may act strongly/independently for the occurrence of VRFs in endodontically treated teeth. Key words:Cone-beam computed tomography, diagnostic accuracy, diagnostic surgery, predictor variables, root canal treatment, vertical root fracture.

Figure 1

Maxillary left first molar with symptomatic apical periodontitis and concomitant marginal lesion with communication. (a) Clinical presentation of the tooth and its surrounding palatal mucosa before the surgical exploration. A sinus tract opening located near gingival margin is observed. (b) A coronal CBCT image showed a vertical palatal alveolar bone loss reaching the apical region thereby producing a J-shaped radiolucency (bone loss halo). (c) Magnified axial CBCT view revealed a bucco-lingually oriented hypodense line (arrows) extending from the disto-buccal to the palatal roots and extensive periradicular bone loss in the mesial aspect of the tooth. (d) After root-end resection and methylene blue staining, the extracted tooth showed the fracture line running through the furcation area.

Figure 2

Surgical finding of a fracture line in a mandibular right central incisor not detected on the CBCT scans. (a) Magnified axial CBCT scan showing absence of hypodense lines and any other radiological sign of VRF. (b) Sagittal CBCT view showing a J-shaped radiolucency with total disruption of the buccal cortical plate of bone. (c) During microsurgical exploration, partial destruction of the buccal cortical plate of bone, total denudation of the buccal surface of the root, and a VRF on the midbuccal aspect of the root were evident after granulomatous tissue removal and root staining with methylene blue dye.

Figure 3

Mandibular left first molar endodontically treated with apical periodontitis accompanied by periodontal breakdown indicative of VRF. (a) Several fracture lines (solid arrows) and an accompanying periradicular bone defect with disruption of the buccal cortical plate can be observed on the axial CBCT scan. (b) Coronal CBCT scan showing buccal alveolar bone loss and J-shaped radiolucency (bone loss halo). (c) The surgical procedure revealed the presence of unprepared lateral ramifications of the root canal system in the apical third of the distal root (dashed arrows). (d) After root-end cavity preparation, no fracture lines were observed on resected root surface. (e) Root-end filling of the exposed canal was performed using EndoSequence root repair material.

Figure 4

Mandibular left central incisor with persistent apical periodontitis and apicomarginal communication suggestive of VRF. (a) Axial CBCT view revealed the absence of fracture lines on the root structure. (b) Sagittal CBCT view showed a J-shaped defect extending from the periapical region to the alveolar crest. (c) Surgical approach showing a large bone defect due to apical pathosis with communication to the alveolar crest without evidence of fracture lines.