Influence of Apical Patency on the Adaptation of the Master Filling Cone: A Cone-beam Computed Tomography Assessment.

Introduction: This study aimed to evaluate if the apical patency can influence the adaptation of the master cone of gutta-percha, quantifying the volume of voids and areas at the last 2 mm of the working length (WL). Materials and Methods: Sixty distobuccal canals of extracted upper molars were divided into 3 groups (n=20) based on the patency length (A: passed 1 mm beyond the apical foramen (AF), B: at the AF and C: 1 mm short of the AF) with the Easy ProDesign Logic 25/0.01 file. Each group was subdivided into 2 subgroups (n=10) based on the WL established to prepare the root canal (1: 1 mm short of the AF or 2: at the AF) with the Easy ProDesign Logic 25/0.05 file. After the scan, void volumes were calculated from the last 2 mm of the WL and void areas at 0 mm, 1 mm and 2 mm of the last of WL, as well as the relation between the tip and taper of the master cone with the amount of void volume and areas. To investigate statistically significant differences, we used the Kruskal-Wallis statistical test. Results: There were more voids in volume when patency was achieved 1 mm beyond the AF and the root canal preparation was conducted at 1mm short of the AF (A1 group). Furthermore, the same group showed more voids areas, mainly on the last millimeter of WL. Conclusion: Achieving apical patency at 1 mm beyond the AF followed by instrumentation 1 mm short of the AF created more voids between the master gutta-percha cone and the root canal wall, especially on the last millimeter of WL.

Cone-beam computed tomography analysis of degenerative changes, condylar excursions and positioning and possible correlations with temporomandibular disorder signs and symptoms

Aim: To describe cone-beam computed tomography (CBCT) features in patients with temporomandibular disorders (TMDs), in terms of degenerative changes, condylar excursions and positioning as well as their possible correlations with signs and symptoms. Methods: Clinical records of patients diagnosed with TMD who were seen between January 2018 and December 2019 were retrospectively evaluated. These patients were divided into the following groups based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD): arthralgia, myalgia, and arthralgia and myalgia groups. The CBCT examination findings of the patients were evaluated in relation to degenerative changes, estimates of condylar excursion, and condylar positioning. The likelihood ratio test was used to verify the possible differences among the three groups, whereas the chi-square test was used to verify the possible differences among the signs and symptoms for the tomographic findings (p ≤ 0.050). Results: In this study, 65 patients with TMD were included. These patients were predominantly female (84.6%) with a mean age of 40.6 years. Tomographic findings of flattening, hyperexcursion and posterior condylar positioning were frequent. A significant correlation was noted between osteophyte and lateral capsule pain (p = 0.027), erosion and posterior capsule pain (p = 0.026), and flattening, pseudocysts (p < 0.050) and condylar excursion (p < 0.001) with mouth opening. Conclusion: Few correlations were noted between degenerative changes and signs of joint pain as well as degenerative changes and condylar hypoexcursion with mouth opening. These correlations were likely associated with division by diagnosis, whereas condylar positioning did not correlate with signs and symptoms

Maxillary Reconstruction with Xenogeneic Bone Graft, Platelet-Rich Fibrin, and Titanium Mesh for Rehabilitation with Implants: A 5-year Follow-Up Study.

Aim: Alveolar deficiency is considered one of the main limitations for placement of osseointegrated implants, as well as for their long-term success, especially in the anterior region of the maxilla. Objective: To report a clinical case of reconstruction of atrophic maxilla with deproteinized bovine bone associated with platelet-rich fibrin (PRF) and titanium mesh and to assess the linear and volumetric bone gains and rehabilitation with implants in a 5-year follow-up. Case: Patient with bone deficiency in the anterior maxilla region underwent bone reconstruction with deproteinized bovine bone associated with PRF and titanium mesh. After six months, the necessary bone height and volume were obtained for placement of implants, and the bone contour was restored in the anterior region, providing functional and aesthetic improvement. The amount of linear and volumetric bone gains was compared to baseline computed tomography scans. Three implants were placed in the grafted region, and a bone tissue sample was obtained at the time of their placement. Histological analysis showed neo-formed bone tissue in contact with the remaining particles of the biomaterial. After six months, the implants were activated, and the prosthesis was placed on the implants, which were monitored for five years. Conclusion: Implants can be placed predictably in regions with vertical and horizontal bone augmentations by using xenogeneic bone grafts associated with titanium mesh and PRF.

Evaluation of cervical peri-implant optical density in longitudinal control of immediate implants in the anterior maxilla region.

OBJECTIVE: This research aimed to longitudinally evaluate the optical density of peri-implant alveolar bone. The data acquired from study participants previously treated with 37 osseointegrated implants were analyzed utilizing the radiographic subtraction technique. METHODS AND MATERIALS: The radiographic follow-ups were performed five times: at the implantation of the prostheses and after 15, 90, 180 and 360 days. Intraoral radiographs were obtained by the paralleling technique using individualized Hanshin-type positioners to guarantee the standardization of the images. The obtained digital images were aligned and equalized before they were submitted to the radiographic subtraction procedure. RESULTS: A significant difference was found between the distal region of Group I (patients treated with osseointegrated implants who required extraction of the dental element) and the 360 day follow-up and the distal region of Group II (patients with healed alveolar sockets) in all follow-up analyses (p < 0.05). We did not observe a significant difference between the groups analyzed and other follow-ups concerning the subcrestal and middle third regions for both the mesial and distal variables (p > 0.05). There was a statistically significant difference in the distal sites [χ2 = 5,745,, p = 0.03], showing a significant association between time and the presence of bone resorption. This association was not shown on the mesial surface (p = 0.16). CONCLUSION: We concluded that there was no statistically significant difference between groups I and II. Using this technique, we were able to quantitatively and qualitatively evaluate the changes in the proximal sites on the digital radiographic images for the analyzed data. Digital subtraction technology to measure peri-implant bone density is an accurate and reproducible technique for quantifying peri-implant bone reactions to different therapeutic modalities.

Utilização de imagens tridimensionais da cavidade sinusal frontal provenientes de tomografia computadorizada de feixe cônico para a identificação forense / Usage of tridimensional cone beam computed tomography imaging of the frontal sinus for human identifications in Forensic Scienses

A unicidade da cavidade sinusal frontal é um importante fator para a identidade humana. O uso de registros de imagens dessa cavidade para a identificação forense é amplamente difundido, sendo uma metodologia secundária segundo a INTERPOL. Recentes avanços nas tecnologias de imagem permitiram o registro de imagens tridimensionais dessa cavidade. Nosso objetivo foi validar a metodologia proposta por Beaini et al. (2015), padronizando critérios para a obtenção de imagens tridimensionais da cavidade sinusal frontal com tomografia computadorizada de feixe cônico e avaliando a capacidade desses dados para a identificação humana. Para tanto, utilizamos um banco de imagens tomográficas de 200 pacientes randomizados e analisados por três observadores. As imagens foram exportadas em formato DICOM e submetidas a dois processos de segmentação distintos e sobreposição tridimensional. Realizou-se a metodologia descrita para estabelecer a identificação entre pacientes randomizados. Os resultados mostraram que há uma diferença significativa entre os processos de segmentação, sendo mais indicada a técnica de segmentação manual. A metodologia proposta por Beaini et al. (2015) foi validada e um total de 166 pacientes foram identificados. O volume da cavidade sinusal possui um elevado potencial de identificação com uma probabilidade aproximada de 85% para determinar o gênero dos indivíduos.

The uniqueness of the frontal sinus cavity is an important factor for establishing human identity. The usage of imaging records of this cavity for human identity is a secondary methodology according to the INTERPOL protocols. Recent advances in imaging technologies have enabled the three-dimensional imaging records of this cavity. Our goal was to validate the methodology proposed by Beaini et al. (2015), by developing standardized criteria for the use of cone beam computed tomography three-dimensional images of the front sinus and evaluating the ability of these data for human identification. The aim of this study was to investigate a total of 200 imaging records from randomized patients that were analyzed by three observers. Images were exported in DICOM format and underwent two distinct segmentation processes and a three-dimensional overlap. The Beaini et al. (2015) technique was applied to establish identification of the randomized patients. My results showed a significant difference between both segmentation processes, with manual segmentation showing the best results. Beaini et al. (2015) technique was validated and a total of 166 patients were identified. The volume of the sinus cavity has a high identification probability with a rough probability of 85% to determine the sex of individuals.

Relato de caso clínico: tumor odontogênico queratocístico na primeira infância / Case report: keratocystic odontogenic tumor in early childhood

Em 2005, o queratocisto odontogênico foi renomeado e reclassificado para tumor odontogênico queratocístico pela Organização Mundial de Saúde. Seu comportamento agressivo e invasivo, sua elevada taxa de recidiva pós-operatória e novas descobertas moleculares possibilitaram esta reclassificação. Neste artigo pretendemos recordar alguns conceitos desta lesão bem como discutir alguns parâmetros de imagem destacando um caso clínico atípico desta lesão. Discutindo de que modo as novas tecnologias de diagnóstico por imagem auxiliam o Cirurgião-Dentista no planejamento terapêutico e no diagnóstico deste tipo de lesão.

In 2005 the Keratocyst Odontogenic was renamed and reclassified to Keratocystic Odontogenic Tumor by the World Health Organization. His aggressive and invasive behavior, its high postoperative recurrence rate and new molecular discoveries made possible this reclassification. This article aims to recall some concepts of this injury as well as discuss some image parameters highlighting an atypical clinical case of injury. Discussing how new technologies diagnostic imaging helps the dentist surgeon in planning and diagnosis of this type of lesion.

Estudo da atual utilização da TCFC pelos Cirurgiões-Dentistas nas diversas especialidades / Study of current use of Cone-Beam CT by dental surgeons in the various specialties

Objetivo: Determinar, dentre os profissionais de Odontologia, o grau de formação e informação quanto ao uso da tomografia computadorizada tipo cone-beam, assim como quantificar e discriminar o uso desta ferramenta diagnóstica no cotidiano das especialidades. Materiais e métodos: Profissionais cursando algum tipo de especialização tiveram que responder a um questionário de respostas certo/errado, que continha parâmetros sobre as indicações do uso da tomografia computadorizada na Odontologia, assim como perguntas que permitiram o levantamento de informações acerca desta ferramenta diagnóstica no tocante a influência do custo do procedimento, necessidade de treinamento específico para interpretação e necessidade de investimento por parte do profissional clínico. Resultados: Pudemos observar que a indicação da técnica não está totalmente esclarecida para muitos Cirurgiões-Dentistas. A porcentagem de desconhecimento foi significativa (27%), por se tratar de radiação ionizante, que pode causar riscos estocásticos e deletérios. Pudemos observar em nossos resultados que existe um embasamento geral da técnica, pois à medida que especialistas de uma certa área acertaram questões correspondentes a outras especialidades, notamos a ocorrência de equívocos de conceitos quando eram questionados sobre o protocolo de uso em sua própria área de conhecimento. Conclusão: A divulgação dos dados obtidos será de grande valia para o clínico geral, bem como para os especialistas, no intuito de reduzir a dose de exposição desnecessária quando da indicação da técnica. A necessidade de aprimorar o conhecimento será sempre necessária, para que não tenhamos apenas o conhecimento geral, mas o específico para a área de atuação de cada um.

Objective: To determine, among dental professionals, the degree of training and information regarding the use of CBCT, as well as to quantify and discriminate the use of this diagnostic tool in specialties daily basis. Materials and methods: Professionals attending specialization courses had to answer a right/wrong answers questionnaire containing parameters of indications for the use of computed tomography in dentistry. Beyond that, they had to answer questions that allowed the collection of information about this diagnostic tool regarding the influence of the cost of the procedure, the need for specific training in the interpretation and need for investment by the clinical professional. Results: We observed that the technique is not entirely clear for many dentists. The percentage of unawareness was significant (27%) considering it is about an ionizing radiation, which can cause deleterious and stochastic risks. We observed in our results that there is a general grounding of the technique, because on the one hand experts of a determined area showed a certain knowledge of other specialties, on the other hand we verified there were misunderstandings of concepts when questioned about the protocol used in their own area of knowledge. Conclusion: The release of the data obtained will be of great value to the general practitioner as well as to specialists in order to reduce the amount of unnecessary exposure in the indication of the technique. Improve knowledge will always be necessary so we will not only have general knowledge, but the specific one to the area of each dentistry professional.

Desenvolvimento de metodologia radiográfica e volumétrica dos diferentes estágios de desenvolvimento dentário para qualificação de material biológico em Engenharia Tecidual / Development of radiographic and volumetric metodologies from diferentes tooth development stages as a qualification for harvesting biological material for Tissue Engeneering

A utilização de Células-tronco e técnicas da Engenharia Tecidual representa um grande avanço tecnológico e beneficiará muitos pacientes com suas conquistas. A descoberta de germes dentários como uma fonte confiável de células-tronco possibilitou diversas pesquisas nesta área. Duailibi et al. (2011) sugeriram uma nova classificação de desenvolvimento dentário baseada pela quantidade de material biológico coletado indicando a necessidade de métodos de diagnóstico por imagem para esta nova classificação. Na literatura diversos trabalhos indicam métodos de classificação dentária e métodos para estimar a idade fisiológica de indivíduos. O presente estudo tem o objetivo de adaptar alguns destes métodos para estimar o estágio de desenvolvimento proposto por Duailibi et al. (2011) consequentemente indicando a quantidade de células-tronco esperadas nas amostras. Para tanto, submeteu-se uma coleção de 67 dentes previamente classificados por Duailibi et al. (2011) à técnica rpcl e à tcfc para a obtenção de imagens e a aplicação de técnicas de estimativas por proporções lineares e volumétricas. Os resultados por análises lineares indicaram valores de R2 para o método de proporção de comprimento CDCP de 0,14050; CCCP de 0,65369; CCCR de 0,5408; CDCR de 0,54074; o método de proporção de área APAD de 0,23925; e método de proporção de volume VPVD de 0,08553, com valor de p menor ou igual à 0,05. Concluindo este estudo indica-se o método de rpcl utilizando a análise do comprimento entre coroa e polpa como o mais indicado para estimar o estágio de desenvolvimento.

The usage of human dental stem cells and tissue engineering technics represents a huge tecnological development and it may benefits many patients in a promissing future. The discovery of suitable source of human dental stem cells were made using tooth buds. Duailibi et al. 2011 indicated a new tooth classification on a stem cell harvesting based research, sugesting new methods for diagnosis these stages. Several method were developed for dental age assesement. The presente study aims to evaluate some of these dental age technics and make adaptations for estimating Duailibi et al. 2011 tooth stages. A 67 tooth sample previoulsy classificated by Duailbi et al. 2011 were submited through periapical parallel long cone X-rays and CBCT analysis. Age estimation ratio methods were applied by measuring tooth/root lenth, crown/root lenth, tooth/pulp lenth, crown/pulp lenth, tooth/poulp área and tooth/pulp volume. Results indicated by linear regression analisys a R2 value of tooth/pulp lenth 0,14050; crown/pulp lenth 0,65369; crown/root lenth 0,5408; tooth/root lenth 0,54074; pulp/tooth volume 0,23925; e tooth/pulp volume de 0,08553, with p value of 0,005. In conclusion , the best method for estimating Duailibi et al. 2011 tooth classification techinic is made by using periapical long cone X-rays using crown/pulp lenth ratio.

Tooth tissue engineering: optimal dental stem cell harvest based on tooth development.

Our long-term objective is to devise reliable methods to generate biological replacement teeth exhibiting the physical properties and functions of naturally formed human teeth. Previously, we demonstrated the successful use of tissue engineering approaches to generate small, bioengineered tooth crowns from harvested pig and rat postnatal dental stem cells (DSCs). To facilitate characterizations of human DSCs, we have developed a novel radiographic staging system to accurately correlate human third molar tooth developmental stage with anticipated harvested DSC yield. Our results demonstrated that DSC yields were higher in less developed teeth (Stages 1 and 2), and lower in more developed teeth (Stages 3, 4, and 5). The greatest cell yields and colony-forming units (CFUs) capability was obtained from Stages 1 and 2 tooth dental pulp. We conclude that radiographic developmental staging can be used to accurately assess the utility of harvested human teeth for future dental tissue engineering applications.