Assessment of furcal perforations in the vicinity of different root canal sealers using a cone beam computed tomography system with and without the application of artifact reduction mode: an ex vivo investigation on extracted human teeth.

OBJECTIVE: To investigate observer ability to diagnose ex vivo simulated endodontic furcal perforations in root-filled teeth from cone beam computed tomography (CBCT) images using different artifact reduction algorithms. STUDY DESIGN: Our study consisted of 135 first maxillary molar teeth. In 89 teeth, furcation perforations were created using dental burs. Forty-six teeth without artificial perforations were used as controls. MTA Fillapex, Activ GP, and AH Plus were used with or without metal posts. All teeth were imaged using Planmeca ProMax 3-D Max CBCT, and four image modes were obtained as without artifact reduction and with artifact reduction in low, medium, and high modes. Images were evaluated by three observers for the presence or absence of furcation perforation using a five-point scale. Weighted kappa coefficients were calculated to assess observer agreement. Receiver operating characteristic analysis was performed. Areas under the curve (AUCs) were calculated for each image mode, observer, treatment group, and reading and were compared using Χ(2) tests, with a significance level of α = 0.05. The effects on diagnosis were calculated using analysis of variance (ANOVA). RESULTS: Intraobserver agreements for all observers ranged from 0.857 to 0.945. Kappa coefficients among different observers ranged from 0.673 to 0.763. AUC values ranged from 0.83 to 0.92, and there were no statistically significant differences (P > .05) between different CBCT image modes. Ratings in Activ GP treatment groups with or without posts showed statistically significant differences (P < .001). CONCLUSIONS: All CBCT image modes performed similarly in detecting furcal perforations near different root canal sealers with or without posts.

Graphite Tattoo on the Gingiva: A Case Report.

INTRODUCTION: Graphite tattoos may easily be confused with amalgam tattoos and have been reported on infrequently in relevant literature. To the best of the authors' knowledge, this is the first case report in which the incineration method was used for the histopathologic diagnosis of a graphite tattoo on the gingiva. CASE PRESENTATION: A 24-year-old female patient was referred to the periodontology department of Ankara University, Ankara, Turkey, for evaluation of an asymptomatic pigmented lesion on the maxillary anterior gingiva. A gray-blackish, irregularly shaped macule was observed on the maxillary anterior attached gingiva between the left central and lateral incisors. Radiographs showed no radiopaque foreign particles or pathologic changes in alveolar bone and related teeth. The pigmented area was removed using an excisional incision. The incineration method was used as a differential diagnosis for the histopathologic examination. There was no additional recurrence of the problem by the end of a 1-year follow-up examination. CONCLUSIONS: The diagnosis of pigmented lesions of the oral cavity and gingiva shows different variations. It is not always possible to distinguish a benign pigmented lesion from an early melanoma on the basis of clinical features alone. A biopsy is usually recommended for focal oral pigmented lesions that cannot be explained by local factors. The incineration method can be used for differential diagnosis between melanin and graphite tattoo accumulation because carbon can be eradicated with this method. However, the same cannot be said for melanin.

Effect of voxel size on accuracy of cone beam computed tomography-aided assessment of periodontal furcation involvement.

OBJECTIVE: To assess the accuracy of cone beam computed tomography (CBCT) images obtained at different voxel sizes in detecting ligature-induced furcation involvement. STUDY DESIGN: Furcation lesions were prepared in 36 molar teeth in rats, and 24 intact teeth served as controls. CBCT Kodak 9000 images at three different voxel sizes were acquired: 0.076 mm, 0.100 mm, and 0.200 mm. Four observers assessed 3 sets of images using a 5-point evaluation scale. κ-Coefficients were calculated for intra- and interobserver agreement. Receiver operating characteristic analysis measured the true positive rate (TPR), true negative rate (TNR), and area under the curve (AUC). Accuracy values were compared by using Mood's Median Chi-Square (α<0.05). RESULTS: Intra- and interobserver agreement ranged from 0.600 to 0.999 and from 0.366 to 0.573, respectively. Highest median AUC and true positive rate (TPR) values were obtained for voxel size of 0.076 mm. The highest median TNR values were obtained for the voxel size 0.1 mm. There were no significant differences (P≥.05) among the median AUC, TPR, or TNR values for the 3 different CBCT voxel sizes. CONCLUSIONS: Given the limitations of this study, all voxel sizes performed similarly in the detection of furcation involvement.

An ex vivo comparison of diagnostic accuracy of cone-beam computed tomography and periapical radiography in the detection of furcal perforations.

INTRODUCTION: The purpose of this study was to assess cone-beam computed tomographic (CBCT) imaging with different voxel sizes and an intraoral sensor in the detection of furcation perforations. METHODS: In 40 teeth, furcation perforations were created, and 40 intact teeth served as the control. Five image sets were obtained: (1) CBCT, 0.1 mm(3) voxel size; (2) CBCT, 0.15 mm(3) voxel size; (3) CBCT, 0.2 mm(3) voxel size; (4) CBCT, 0.4 mm(3) voxel size; and (5) digital periapical images. Images were evaluated twice by 3 observers. Perforation widths were measured by CBCT software. Receiver operating characteristic analysis was used to assess the observers' ability to detect perforation, and area under the curve values were compared by using t tests, with a significance level of α = 0.05. RESULTS: No differences (P > .05) were found between any of the median area under the curve and true positive rate values obtained with different CBCT voxel sizes. Actual perforation width correlated highly with CBCT width measurements. CONCLUSIONS: Low-resolution CBCT imaging can be preferred for furcation perforation diagnosis because of its low dose and reliable diagnostic outcome.