Assessment of simulated internal resorption cavities using digital and digital subtraction radiography: a comparative study

Evaluation of the efficacy of different irrigation activation techniques in removing of calcium hydroxide on teeth with the simulated internal root resorption cavity: a confocal laser scanning microscope analysis

The aim of this study is to evaluate the effect of different irrigation activation methods on root canal sealer penetration in teeth with simulated internal root resorption (IRR) and calcium hydroxide (CH) applied using a confocal laser scanning microscope (CLSM). 60 incisors with a single root and a single canal were included in the study. IRR cavities were created in the middle third of the root canal, and CH was placed. The samples were randomly divided into 4 groups (n = 15) according to the irrigation activation method to be tested: standard needle irrigation (SNI), sonic activation (EDDY), photon-induced photoacoustic flow (PIPS), and shock wave enhanced emission photoacoustic flow (SWEEPS). After irrigation activation applications, the root canals were obturated. Sections of 1.0 ± 0.1 mm were taken from the apical, middle, and coronal regions of each sample. The penetration area (µm2) and maximum penetration depth (µm) of the root canal sealer were examined by CLSM and analyzed using ImageJ software. Statistical analysis was performed with a one-way ANOVA and post-hoc Tukey test at the P < 0.05 significance level. Among all irrigation activation methods tested, both the penetration area and maximum penetration depth of the root canal sealer were greater in the coronal region than in the apical region (p < 0.05). In the IRR region, there was no difference in terms of maximum penetration depth between PIPS and SWEEPS (p > 0.05), it was highest in SWEEPS (p < 0.05). PIPS and SWEEPS were better than other irrigation activation methods in the penetration of root canal sealer in the resorption areas of teeth with IRR.

Exploring digital filters for internal root resorption: how can we improve the diagnosis of small lesions?

OBJECTIVES

This study aimed to evaluate the impact of enhancement filters in detecting small simulated internal root resorptions (IRR).

METHODS:

Forty-two extracted human teeth were sectioned, connected, and stored in a dry human jaw and X-rayed with photostimulable phosphor plates (PSPs), composing the control group (CG). In the middle-third of the root canals, IRR lesions were simulated using Da Silveira protocol. Later, the specimens were X-rayed to create the test group (TG). All images acquired were exported with seven enhancement filters plus the original image. Three examiners used a five-point Likert scale to evaluate the images regarding the presence/absence of IRR. Diagnostic efficacy was assessed from sensitivity and specificity results. Comparison among filters was performed by using receiver operating characteristic (ROC) curve analysis.

RESULTS:

Moderate values of Kappa interexaminer (0.403-0.620) and high values of Kappa intraexaminer (0.757-0.915) were observed. The best performance occurred in the CG (p < 0.05). Original images presented the greatest sensitivity and area under the ROC curve (0.595-0.750), while the Endo filter presented the greatest specificity (0.952). Inversion and Pseudo-3D images produced the greatest doubt in the diagnosis, significant for CG with the Pseudo-3D filter (p < 0.05).

CONCLUSIONS:

The Original and 'Endo' filters should be chosen as it offers greater diagnostic ability and allows more confidence during the evaluation.

Diagnostic efficacy of different cone beam computed tomography scanning protocols in the detection of chemically simulated external root resorption

OBJECTIVES

The aim of this study was to evaluate the efficacy of different high-resolution cone beam computed tomography protocols in the diagnosis of chemically simulated external root resorption (ERR).

STUDY DESIGN

ERR was simulated in 3 sizes by using an acid decalcification protocol in the cervical, middle, and apical thirds of 30 single-rooted premolars. Four scans of each tooth were acquired with different voxel sizes: 0.080, 0.085, 0.120, and 0.133 mm. The images were analyzed by 2 blinded evaluators for the presence of ERR. The evaluation of diagnostic performance was based on receiver operating characteristic (ROC) curve analysis.

RESULTS

No statistically significant differences were found in the detection of ERR with regard to lesion sizes or the different root thirds. Areas under the ROC curve were 0.901, 0.892, 0.887, and 0.767 for voxel sizes of 0.080, 0.085, 0.120, and 0.133 mm, respectively. Voxel sizes of 0.080 and 0.085 mm presented significantly larger areas under the ROC curve compared with the voxel size of 0.133 mm. There were no statistically significant differences among the protocols with the use of voxel sizes of 0.080, 0.085, and 0.120 mm.

CONCLUSIONS

Cone beam computed tomography examinations with higher-resolution protocols demonstrated better performance in the diagnosis of ERR. Further investigations using simulations that more closely resemble the actual ERR process are warranted.

Digital subtraction radiography in detection of vertical root fractures: accuracy evaluation for root canal filling, fracture orientation and width variables. An ex-vivo study

OBJECTIVE

Ex-vivo evaluation of the detectability of vertical root fractures (VRFs) using digital subtraction radiography (DSR) and conventional digital periapical radiography (CDPR); investigation of the effect of root canal filling, x-ray angulation, and thickness of the VRF in the diagnostic accuracy.

MATERIALS AND METHODS

Sixty root canals were mechanically prepared and radiographed either with a gutta-percha root canal filling or without, at 0^o and ± 10^o. VRFs were introduced with a universal testing machine. The width and angulation of the fracture line with the radiographic beam were calculated. DSR was performed comparing radiographs obtained prior to and after the VRF induction. Five examiners evaluated the resultant images and analysis was performed using receiver operator characteristic (ROC) statistics and binary logistic regression tests.

RESULTS

No significant differences in sensitivity, specificity, and the areas under the ROC curves (AUC) between the CDPR and DSR were detected (p > 0.05), except for root canal filled teeth where the AUC for DSR was higher (p < 0.05). Using DSR, a VRF was 1.3 times more likely to be diagnosed [95% confidence intervals (CI): 1.045-1.59; p = 0.018]. A correct diagnosis was 2.399 times more likely to occur in non-filled teeth regardless of the radiographic technique (95% CI 1.940-2.965; p = 0). The regression coefficients were positive for width and negative for angle.

CONCLUSIONS

DSR showed a better diagnostic accuracy of VRFs compared with CDPR, in single root canal filled teeth. The angulation, the width, and the presence of a root canal filling affected the diagnostic potential.

CLINICAL RELEVANCE

DSR is a cost- and time-effective imaging technique that could contribute in early diagnosis of VRFs.

Accuracy of Different Imaging CBCT Systems for the Detection of Natural External Radicular Resorption Cavities: An Ex Vivo Study

OBJECTIVE

The aim of this study was to compare the sensitivity and specificity of 3 different systems of cone-beam computed tomography (CBCT) in the detection of natural external root resorption (ERR) cavities using microtomography as the gold standard.

METHOD

A sample of 126 ex vivo teeth were submitted to a microtomography examination to verify the presence/absence of ERR cavities. Then, they were divided into the control group: 85 teeth that did not present with an ERR cavity; and experimental group: 41 teeth that presented with 1 or more ERR cavities. The size of the natural ERR cavities varied from 2.46 mm³ to 3.11 mm³, which corresponded to cavities of 1.67 mm and 1.81 mm in diameter, respectively. The teeth were placed on a dry human mandible for scanning in each of the 3 protocols with different voxel sizes: 0.25 mm, 0.20 mm, and 0.166 mm.

RESULTS

The accuracy of the 3 protocols evaluated in this study are listed in decreasing order: 60.3% for a voxel size of 0.20 mm, 56.7% for a voxel size of 0.166 mm, and 46.7% for a voxel size of 0.25 mm; these are smaller values than previous studies have obtained using artificial ERR cavities. Statistically significant results were not found among the 3 CBCT protocols that were used (P > .05), and the receiver operating characteristic curve shows the small differences found between the protocols.

CONCLUSION

The results indicate that CBCT presents, for natural ERR, lower sensitivity and specificity values than those detected in previous studies of artificial cavities. The results demonstrate that natural ERR is neither easily observed nor accurately located by CBCT, as previous studies using artificial ERR indicated.

Diagnostic accuracy of phosphor plate systems and conventional radiography in the detection of simulated internal root resorption

OBJECTIVE

To evaluate the performance of conventional radiography and photostimulable phosphor (PSP) plate in the detection of simulated internal root resorption (IRR) lesions in early stages.

MATERIALS AND METHODS

Twenty single-rooted teeth were X-rayed before and after having a simulated IRR early lesion. Three imaging systems were used: Kodak InSight dental film and two PSPs digital systems, Digora Optime and VistaScan. The digital images were displayed on a 20.1″ LCD monitor using the native software of each system, and the conventional radiographs were evaluated on a masked light box. Two radiologists were asked to indicate the presence or absence of IRR and, after two weeks, all images were re-evaluated. Cohen's kappa coefficient was calculated to assess intra- and interobserver agreement. The three imaging systems were compared using the Kruskal-Wallis test.

RESULTS

For interexaminer agreement, overall kappa values were 0.70, 0.65 and 0.70 for conventional film, Digora Optima and VistaScan, respectively. Both the conventional and digital radiography presented low sensitivity, specificity, accuracy, positive and negative predictive values with no significant difference between imaging systems (p = .0725).

CONCLUSIONS

The performance of conventional and PSP was similar in the detection of simulated IRR lesions in early stages with low accuracy.

Assessment of Root Perforation within Simulated Internal Resorption Cavities Using Cone-beam Computed Tomography

INTRODUCTION

Internal root resorption lesions may perforate external root surfaces, which may not be detectable on conventional radiographic images. The purpose of this study was to evaluate the accuracy of cone-beam computed tomographic (CBCT) imaging in the detection of small perforations within simulated internal resorption cavities.

METHODS

Artificial internal root resorption cavities with minimal (0.1-0.2 mm) wall thickness were prepared at 64 sites on buccal and lingual halves of 32 single-rooted mandibular teeth that had been split mesiodistally. Perforations with 0.5-mm diameters were produced using a #40 K-file in half of the specimens. All teeth were placed in dry sheep mandibles and imaged using a NewTomVGi CBCT scanner (6 × 6 cm field of view, 0.1-mm resolution; NewTomQR srl, Verona, Italy). Two observers evaluated the images. Interexaminer and intraexaminer agreement were assessed using the kappa statistic. Sensitivity, specificity, and predictive values were used to assess diagnostic accuracy.

RESULTS

Intra- and interobserver agreement on perforation detection were high. The sensitivity and specificity of CBCT-based detection of perforation in internal root resorption were 81.3% and 84.4%, respectively.

CONCLUSIONS

CBCT imaging is useful for perforation detection in internal root resorption defects.

Exposure time reduction of secondary radiographs used in digital subtraction radiography in detecting intrabony change

Objectives

Digital subtraction radiography (DSR) is a suitable technique for detecting incipient bone changes. However, in DSR, one or more follow-up radiographs must be taken. The aim of this study was to assess the possibility of reducing the exposure time for the radiographs that follow the initial one.

Methods

Maxillary premolar and molar radiographic images of a dry skull were taken with a digital radiography system. The initial radiographs, without bone chips, were taken at 0.32 and 0.16 s. Then, five bone chips (weight range 7–15 mg) were placed on the maxillary molar buccal side of the dry skull. Secondary radiographs were taken at 0.32-, 0.16-, 0.08-, 0.04-, and 0.02-s exposure times. For each bone chip, radiographs were taken three times. The secondary and initial images were subtracted to yield subtraction images. Four observers were asked to evaluate bone change visibility in the subtraction images. The Friedman test was used for statistical analysis.

Results

Significant differences were seen at each of the settings for the 0.32-s group (p = 1.24e−030) and 0.16-s group (p = 7.52e−009). By comparing the different groups, observer evaluations indicated that visibility changed when the secondary radiograph was taken at 1/8 of the exposure time of the initial radiograph. In both groups, the visibility of the 0.02-s subtraction image was significantly lower than that of the other subtraction images.

Conclusion

In DSR, the exposure time of the secondary radiograph can be reduced to 1/4 of the exposure time of the initial radiograph.