CBCT post-processing tools to manage the progression of invasive cervical resorption: a case report

This case report aimed to highlight the usefulness of cone beam computed tomography (CBCT) and its post-processing tools for the diagnosis, follow-up and treatment planning of invasive cervical resorption (ICR). A 16-year-old female patient was referred for periapical radiographic examination, which revealed an irregular but well demarcated radiolucency in the mandibular right central incisor. In addition, CBCT scanning was performed to distinguish between ICR and internal root resorption. After the diagnosis of ICR, the patient was advised to return shortly but did so only six years later. At that time, another CBCT scan was performed and CBCT registration and subtraction were done to document lesion progress. These imaging tools were able to show lesion progress and extent clearly and were fundamental for differential diagnosis and treatment decision.This case report aimed to highlight the usefulness of cone beam computed tomography (CBCT) and its post-processing tools for the diagnosis, follow-up and treatment planning of invasive cervical resorption (ICR). A 16-year-old female patient was referred f274476480sem informaçãosem informaçãoCom este relato de caso clínico objetiva-se enfatizar a contribuição das ferramentas de pós-processamento aplicadas às imagens de tomografia computadorizada de feixe cônico (TCFC) no diagnóstico, acompanhamento e decisão do tratamento de reabsorção cervi

Evaluation of Threshold Values for Root Canal Filling Voids in Micro-CT and Nano-CT Images

While several materials and techniques have been used to assess the quality of root canal fillings in micro-CT images, the lack of standardization in scanning protocols has produced conflicting results. Hence, the aim of this study was to determine a cutoff voxel size value for the assessment of root canal filling voids in micro-CT and nano-CT images. Twenty freshly extracted mandibular central incisors were used. Root canals were prepared with nickel titanium files to an ISO size 40/0.06 taper and then filled with a single cone (40/0.06 taper) and AH Plus sealer. The teeth were scanned with different voxel sizes with either micro-CT (5.2, 8.1, 11.2, and 16.73 μm) or nano-CT (1.5 and 5.0 μm) equipment. Images were reconstructed and analyzed with the NRecon and CTAn software. Void proportion and void volume were calculated for each tooth in the apical, middle, and coronal thirds of the root canal. Kruskal-Wallis and post hoc Mann–Whitney U tests were performed with a significance level of 5%. In micro-CT images, significantly different results were detected among the tested voxel sizes for void proportion and void volume, whereas no such differences were found in nano-CT images (p>0.05). Micro-CT images showed higher void numbers over the entire root length, with statistically significant differences between the voxel size of 16.73 μm and the other sizes (p<0.05). The values of the different nano-CT voxel sizes did not significantly differ from those of the micro-CT (5.2, 8.1, and 11.2 μm), except for the voxel size of 16.73 μm (p<0.05). All tested voxel sizes enabled the detection of root canal filling voids except for the voxel size of 16.73 μm. Bearing in mind the limitations of this study, it seems that a voxel size of 11.2 μm can be used as a reliable cutoff value for the assessment of root canal filling voids in micro-CT imaging.Publisher's Versio

Comparison of periapical images and computerized tomography in the evaluation of alveolar bone loss

Made available in DSpace on 2014-07-29T15:21:56Z (GMT). No. of bitstreams: 1 Dissertacao Karla F Vasconcelos.pdf: 1466749 bytes, checksum: 7b601b9e8f64b11bffa5aec4d7b36d76 (MD5) Previous issue date: 2010-02-26Interproximal and periapical radiographs are most suited to periodontal evaluation, but are limited when it comes to diagnosis of bone condition. In dentistry, cone beam computed tomography (CBCT) has been most frequently used when a threedimensional evaluation is needed. The aim of this study was to compare periapical radiographs and volumetric CT imaging in detecting and localizing alveolar bone loss, by comparing linear measurements of the height, depth and width of the defects and identifying combined bone defects in tomographic images. The images were selected from a secondary database containing images of patients referred for periodontal evaluation. The sample consisted of 51 sites showing both horizontal and vertical bone loss, assessed by three previously-trained examiners. The results showed that there were no statistically significant differences between the imaging methods compared in terms of identification of the pattern of bone loss. However, there were differences between the two methods when the distance between the cementoenamel junction (CEJ) and the alveolar crest (AC) was measured. When the distance between the CEJ and the deepest point and the width of the defect were measured, the methods showed no statistically significant difference. In this study, 30.76% of the 39 teeth evaluated had combined bone defects. It was concluded that the two methods differ when detecting the height of the alveolar bone crest, but present similar views of the depth and width of bone defects. CBCT was the only method that allowed for an analysis of the buccal and lingual/palatal surfaces and an improved visualization of the morphology of the defect.As radiografias interproximais e periapicais são as mais indicadas para avaliação periodontal, porém apresentam limitações no diagnóstico da condição óssea. A tomografia computadorizada volumétrica tem sido o recurso de imagem mais utilizado quando há necessidade de avaliação tridimensional em Odontologia. O objetivo desse estudo foi comparar radiografias periapicais e imagens tomográficas volumétricas na detecção e localização de perdas ósseas alveolares, por meio da comparação de medidas lineares da altura, profundidade e largura dos defeitos e identificação dos defeitos ósseos combinados nas imagens tomográficas. As imagens foram selecionadas a partir de um banco de dados secundário contendo imagens de pacientes com indicação para avaliação periodontal. A amostra foi composta por 51 sítios apresentando perdas ósseas horizontais e verticais avaliados por três examinadores previamente treinados. Os resultados mostraram que os métodos de imagem comparados não apresentaram diferenças estatisticamente significantes entre si quanto à identificação do padrão da perda óssea. Entretanto, as medidas da distância entre a junção cementoesmalte (JCE) à crista alveolar (CA), apresentaram diferenças entre os dois métodos. Quando comparadas as medidas da distância da JCE ao ponto mais fundo do defeito e da largura do defeito, os métodos não apresentaram diferenças estatisticamente significantes. Neste estudo 30,77% dos 39 dentes avaliados apresentavam defeitos ósseos combinados. Concluiu-se que os dois métodos apresentam diferenças na detecção da altura da crista óssea alveolar, porém com visualização similar da profundidade e largura dos defeitos ósseos. A tomografia computadorizada volumétrica foi o único método que permitiu análise das faces vestibular e lingual/palatina e melhor visualização da morfologia do defeito

Micro-computed tomography of maxillary implant sites reconstructed with autogenous and xenogenous bone graft

Orientador: Frab Norberto BoscoloTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: O conhecimento da microarquitetura óssea desempenha importante papel no sucesso das reconstruções ósseas e posterior reabilitação com implantes dentários. Os objetivos dessa pesquisa foram: 1. Avaliar a microarquitetura óssea de sítios da maxila, que foram reconstruídos com enxertos ósseos, autógeno e xenógeno e 2. Avaliar tridimensional e bidimensionalmente a formação óssea na superfície dos parafusos de fixação (BIC-Bone-to-implant contact). Doze amostras contendo parafusos de fixação recobertos por 0,5 a 1mm de osso humano foram removidas com auxílio de uma broca trefina, após seis meses da colocação de blocos de enxerto em maxila de 8 pacientes, cinco mulheres e três homens, com média de idade entre 50 anos. Sete de sítios xenógenos e cinco de autógenos. As amostras foram avaliadas por meio de imagens obtidas pelo microtomógrafo SkyScan 1173 e por meio da técnica histológica de Stevenels blue e Van Giesen red. Para caracterizar a microarquitetura foram avaliados: a razão volume ósseo/volume tecidual, espessura das trabéculas, distância trabecular, número de trabéculas e densidade de conectividade, em três áreas distintas (enxerto/transição/osso nativo). O cálculo do BIC 2D foi realizado em imagens histológicas e microtomográficas. O BIC 3D foi viabilizado em áreas selecionadas em 17 amostras, entretanto, apenas em imagens adquiridas por microtomografia. Quando os parâmetros da microarquitetura foram comparados entre as áreas, foram observadas diferenças estatísticas (p<0,05) na espessura e distância das trabéculas, entre a área de osso nativo e do enxerto, apenas nas amostras autógenas. As amostras xenógenas não apresentaram diferenças entre as áreas. Quando os dois tipos de enxerto foram comparados entre si, diferenças estatísticas (p<0,05) foram encontradas entre o volume de tecido ósseo, espessura entre as trabéculas e a distância entre as trabéculas. O cálculo do BIC 2D revelou semelhança entre as técnicas (p=0,802) e também entre os tipos de enxerto (p=0,097). Avaliando os valores do BIC 3D, observou-se diferença estatística significante nos valores do BIC entre as diferentes áreas, osso e enxerto, com valores mais altos nas áreas de osso nativo. Esses dados estruturais e observações obtidas a partir de imagens microtomográficas proporcionam valiosa caracterização desses sítios e oportunidade de futuras correlações com estudos de elementos finitos e resultados clínicosAbstract: The knowledge of bone microarchitecture is an important role in the success of bone reconstructions and following rehabilitation with dental implants. Thus, the main objectives of this study were: 1) To characterize the microarchitecture of implant bone sites reconstructed with bone grafts and 2) To assess in two and three-dimensions the percentage of bone in contact with bone graft fixing screws (BIC-Bone-implant contact). Six months after graft placement of blocks in the maxilla of eight patients (five women and three men, with a mean of 50 years of age) twelve samples containing fixing screws covered by 0.5 to 1 mm of human bone were removed using a trephine drill. Five were from sites that had received autogenous grafts and seven from sites that had received xenogeneic grafts. Samples were evaluated by micro tomography images obtained by the SkyScan 1173 (Bruker, Kontich, Belgium) device and by histological technique with Stevenels blue e Van Giesen red solutions. To characterize the bone microarchitecture, bone volume, trabecular thickness, trabecular distance, trabecular number and connectivity in three distinct areas (graft / transition / native bone) were evaluated. The 2D BIC was performed in histological and microtomography images. The 3D BIC was performed only in images acquired by microtomography in whole sample. When the microtomography bone parameters were compared between areas, statistical differences were noted only in the thickness and distance of the trabecular area between the native bone and autogenous graft (p<0.05). No statistically significant differences were observed between these areas in the xenogenous sample. When the parameters were compared between two types of grafts, statistical differences were found between the bone volume (p<0.05), the trabecular thickness (p<0.05) and trabecular separation (p<0.05).While calculating the BIC 2D revealed similarity when comparing values obtained by both techniques (p=0.802), and both grafts (p=0.097). It was observed statistically significant difference in values of BIC 3D in different areas (bone and graft) (p=0.0021) with the highest values in areas of native bone. The structural data and observations obtained from micro-computed tomography images provided valuable characterization of sites that received bone grafts and the opportunity for future correlations with finite element studies and clinical outcomesDoutoradoRadiologia OdontologicaDoutora em Radiologia Odontológic

A Survey On Dental Undergraduates’ Knowledge Of Oral Radiology

Dentists’ incorrect behavior with regards to Oral Radiology, as reported in the literature, has been related to inadequate training of undergraduates. Aim: This study assessed dental undergraduates’ knowledge of Oral Radiology. Methods: A questionnaire containing 30 questions pertaining to three domains - General Principles, Radiobiology/Radioprotection and Technique/Interpretation - was used as data collection instrument. A total of 195 students answered the questionnaires. Results: No statistically significant differences were found between second-, third- and fourthyear students (p&gt;0.05) when the whole questionnaire and the General Principles domain (p&gt;0.05) were considered. The Technique/Interpretation domain presented a borderline statistical significance level (p=0.051), with more correct answers attributed to second-year students. A statistically significant difference (p&lt;0.05) was seen for the Radiobiology/Radioprotection domain, in which the fourth-year students performed better. Conclusions: Dental undergraduates’ knowledge of Oral Radiology did not increase or decrease significantly comparing the undergraduate years. However, with the exception of the Technique/Interpretation domain, students of more advanced undergraduate years answered more correctly the questions. Nevertheless, the Technique/ Interpretation domain should be reinforced throughout the undergraduate course.122109-11

A survey on dental undergraduates’ knowledge of oral radiology

Dentists’ incorrect behavior with regards to Oral Radiology, as reported in the literature, has been related to inadequate training of undergraduates. Aim: This study assessed dental undergraduates’ knowledge of Oral Radiology. Methods: A questionnaire containing 30 questions pertaining to three domains - General Principles, Radiobiology/Radioprotection and Technique/Interpretation - was used as data collection instrument. A total of 195 students answered the questionnaires. Results: No statistically significant differences were found between second-, third- and fourth-year students (p>0.05) when the whole questionnaire and the General Principles domain (p>0.05) were considered. The Technique/Interpretation domain presented a borderline statistical significance level (p=0.051), with more correct answers attributed to second-year students. A statistically significant difference (p<0.05) was seen for the Radiobiology/Radioprotection domain, in which the fourth-year students performed better. Conclusions: Dental undergraduates’ knowledge of Oral Radiology did not increase or decrease significantly comparing the undergraduate years. However, with the exception of the Technique/Interpretation domain, students of more advanced undergraduate years answered more correctly the questions. Nevertheless, the Technique/ Interpretation domain should be reinforced throughout the undergraduate course