Influence of CBCT-based volumetric distortion and beam hardening artefacts on the assessment of root canal filling quality in isthmus-containing molars.

OBJECTIVES: To evaluate the influence of artefacts in cone beam CT (CBCT) images of filled root canals in isthmus-containing molars. METHODS: 10 teeth presenting canals with an isthmus were instrumented and filled with a thermoplasticised obturation technique. The teeth were scanned using a micro-CT device and two CBCT devices: 3D Accuitomo 170 (ACC) and NewTom VGi evo (NT), with different acquisition protocols: larger and smaller voxel size. Three examiners assessed the CBCT images for: (1) detection of filling voids; (2) assessment of under- or overestimation of the filling material and (3) resemblance of CBCT images to the reference standard. Analyses of Task 1 yielded accuracy, sensitivity and specificity for detection of filling voids. For tasks 2 and 3, statistical analysis was performed using Wilcoxon test. The level of significance was set at p < .05. RESULTS: For Task 1, ACC showed higher sensitivity, whereas NT presented higher specificity. No significant difference was found between the protocols in ACC, however, for NT, differences between protocols were significant for all diagnostic values. In Task 2, visualisation of the filling was overestimated for NT, while for ACC, underestimation was observed. For Task 3, images with smaller voxel size were more similar to the reference image, for both CBCT devices. CONCLUSIONS: Different artefacts compromise the detection of filling voids on CBCT images of canals in mandibular molars with isthmus. ACC and NT present rather similar diagnostic accuracy, even though artefact expression remains device-specific.

Delayed alveolar bone repair and osteonecrosis associated with Zoledronic Acid therapy in rats: macroscopic, microscopic and molecular analysis.

OBJECTIVE: This study aims to evaluate bone repair and the development of the medication related osteonecrosis of the jaw (MRONJ) associated with the use of zoledronic acid in Wistar rats. METHODOLOGY: 48 male Wistar rats were divided into four groups: ZA, treated with intraperitoneal zoledronic acid, 0.6 mg/kg every 28 days, totaling five doses; control (C), treated with 0.9% sodium chloride; ZA-surgical (SZA) and C-surgical (SC), submitted to extraction of the right upper molars 45 days after the first application. Alveolar bone repair was evaluated by macroscopic and histological analysis. Protein expression evaluations were performed by qPCR. RESULTS: Macroscopic evaluation showed that 91.66% (11) of the animals in the SZA group and 41.66% (5) from the SC group presented solution of epithelium continuity (P<0.05). All animals in the SZA group and none in the SC group had bone sequestration. The area of osteonecrosis was higher in the SZA group than in the SC group (P<0.05). In molecular evaluation, the SZA group presented changes in the expression of markers for osteoclasts, with increased RANK and RANKL, and a decrease in OPG. CONCLUSION: The results highlighted strong and evident interference of zoledronic acid in bone repair of the socket, causing osteonecrosis and delayed bone remodeling.

Delayed alveolar bone repair and osteonecrosis associated with Zoledronic Acid therapy in rats: macroscopic, microscopic and molecular analysis

Abstract Objective This study aims to evaluate bone repair and the development of the medication related osteonecrosis of the jaw (MRONJ) associated with the use of zoledronic acid in Wistar rats. Methodology 48 male Wistar rats were divided into four groups: ZA, treated with intraperitoneal zoledronic acid, 0.6 mg/kg every 28 days, totaling five doses; control (C), treated with 0.9% sodium chloride; ZA-surgical (SZA) and C-surgical (SC), submitted to extraction of the right upper molars 45 days after the first application. Alveolar bone repair was evaluated by macroscopic and histological analysis. Protein expression evaluations were performed by qPCR. Results Macroscopic evaluation showed that 91.66% (11) of the animals in the SZA group and 41.66% (5) from the SC group presented solution of epithelium continuity (P<0.05). All animals in the SZA group and none in the SC group had bone sequestration. The area of osteonecrosis was higher in the SZA group than in the SC group (P<0.05). In molecular evaluation, the SZA group presented changes in the expression of markers for osteoclasts, with increased RANK and RANKL, and a decrease in OPG. Conclusion The results highlighted strong and evident interference of zoledronic acid in bone repair of the socket, causing osteonecrosis and delayed bone remodeling.

Zygomaticofacial foramen location accuracy and reliability in cone-beam computed tomography.

OBJECTIVE: This study aimed to evaluate the possibility of detecting the zygomaticofacial foramen (ZFF) in cone-beam computed tomography (CBCT). MATERIALS AND METHODS: This study evaluated ZFFs in 151 macerated skulls (302 zygomatic bones, ZBs) by physical inspection, in which the presence and diameters of the ZFFs were determined. These data were compared with the CBCT images of the skulls to determine the accuracy of CBCT in detecting ZFFs. The diameters were measured by insertion of steel wires with known thicknesses into the ZFFs. The CBCT images were acquired by an i-CAT Classic® (International Imaging Sciences, Hatfield, PA) connected to a workstation (Model ITOX Midtower Workstation; Imaging Sciences International®) with a 20-inch Eizo monitor. The images were generated in coronal, sagittal and axial slices to evaluate the best tomographic plane for ZFF visualization. RESULTS: The incidence of ZFF found by physical inspection was one foramen in 44% of ZBs (n = 133), two foramina in 28% (n = 86), three foramina in 8% (n = 24) and four foramina in 1% (n = 2). ZFF was absent in 19% (n = 57) of ZBs. The average diameter was 0.57 mm (± 0.27 mm). All foramina were observed in all tomography images. CONCLUSION: This preliminary study supports the conclusion that a CBCT scan has excellent accuracy in evaluating ZFFs.

GP5+/6+ SYBR Green methodology for simultaneous screening and quantification of human papillomavirus.

BACKGROUND: Detection and quantification of human papillomavirus (HPV) may help in predicting the evolution of HPV infection and progression of associated lesions. OBJECTIVES: We propose a novel protocol using consensus primers GP5+/6+ in a SYBR Green quantitative real-time (Q-RT) polymerase chain reaction (PCR). The strategy permits screening for HPV infection and viral load quantification simultaneously. STUDY DESIGN: DNA from 153 archived cervical samples, previously tested for HPV detection by GP5+/6+ PCR and typed by EIA-RLB (enzyme immunoassay-reverse line blot) or sequence analysis, was analysed using SYBR Green Q-RT PCR. Melting temperature assay (T(m)) and cycle threshold (C(t)) were used to evaluate HPV positivity and viral load. The T(m) in the range of 77-82 degrees C was considered to be positive for HPV-DNA. HPV results generated through GP5+/6+ conventional PCR were considered the gold standard against which sensitivity and specificity of our assay were measured. RESULTS: Out of 104 HPV positive samples, 100 (96.2%) were also determined as positive by SYBR Green Q-RT PCR; of the 49 HPV-negative samples, all were determined as negative. There was an excellent positivity agreement (kappa=0.94) between the SYBR Green Q-RT and the previous methods employed. The specificity and sensitivity were 100% and 96.2%, respectively. Comparison of SYBR Green Q-RT and TaqMan oligo-probe technologies gave an excellent concordance (rho(c)=0.95) which validated the proposed strategy. CONCLUSIONS: We propose a sensitive and easy-to-perform technique for HPV screening and viral load quantification simultaneously.

Medidas lineares em radiografias panorâmicas digitalizadas, fornecidas por programa de imagem para planejamento na implantodontia: correlação e análise crítica / The linear measurementson digital panoramic radiographies obtained in two image softwares for presurgical implant: correlation and critical analysis

O objetivo da presente pesquisa foi avaliar, comparativa mete, as medidas lineares em radiografias panorâmicas obtidas no programa Planimp, desenvolvido para planejamento pré-cirúrgico em implantes, com as obtidas pelo método manual, utilizando um paquímetro digital. A amostra constou de 50 radiografias panorâmicas de pacientes edêntulos, nas quais foram marcados pontos de referência para delimitar 14 distâncias anatômicas em cada radiografia. As radiografias foram digitalizadas por meio de um scanner HP Scanjet 4C/T (Hewllett Pa ck a rd). As mensurações lineares das distâncias anatômicas foram realizadas pelo método manual (paquímetro digital) e pelo método digital (Planimp). Os dados obtidos foram submetidos à análise estatística por meio do teste de variância, com nível de significância de 5 por cento. Esta análise estatística mostrou que não houve diferença significante entre as medidas manuais e digitais. A partir dos resultados concluiu- se que o programa Planimp apresentou desempenho adequado para a calibração da imagem radiográfica, bem como para a mensuração de distâncias lineares.

The present study evaluated the linear measurements on panoramic radiographs obtained in image software for presurgical implant planning (Planimp) compared to the manual technique using a digital caliper. The sample comprised 50 panoramic radio graphs of edentulous patients, on which reference points were traced for delineation of 14 anatomical dimensions on each radiograph. The radiographs were digitized with a HP Scanjet 4C/T scanner (Hewllett Packard). Linear measurements of the anatomical dimensions were achieved by the manual method (digital caliper) and digital method (Planimp software). The data achieved were submitted to statistical analysis of variance, at a significance levelof 5 percent. This statistical analysis has not demonstrate any significant difference between the manual and digital measurements. The results allowed the conclusion that the Planimp software displayed proper performances for calibration of the radiographic image andfor measurement of linear dimensions.