Alfredo Franco Queiroz

Comparison of the diagnostic accuracy of direct digital radiography system, filtered images, and subtraction radiography

Background: To compare the diagnostic accuracy of three different imaging systems: Direct digital radiography system (DDR-CMOS), four types of filtered images, and a priori and a posteriori registration of digital subtraction radiography (DSR) in the diagnosis of proximal defects. Materials and Methods: The teeth were arranged in pairs in 10 blocks of vinyl polysiloxane, and proximal defects were performed with drills of 0.25, 0.5, and 1 mm diameter. Kodak RVG 6100 sensor was used to capture the images. A posteriori DSR registrations were done with Regeemy 0.2.43 and subtraction with Image Tool 3.0. Filtered images were obtained with Kodak Dental Imaging 6.1 software. Images (n = 360) were evaluated by three raters, all experts in dental radiology. Results: Sensitivity and specificity of the area under the receiver operator characteristic (ROC) curve (Az) were higher for DSR images with all three drills (Az = 0.896, 0.979, and 1.000 for drills 0.25, 0.5, and 1 mm, respectively). The highest values were found for 1-mm drills and the lowest for 0.25-mm drills, with negative filter having the lowest values of all (Az = 0.631). Conclusion: The best method of diagnosis was by using a DSR. The negative filter obtained the worst results. Larger drills showed the highest sensitivity and specificity values of the area under the ROC curve.

Accuracy in the diagnosis of vertical root fractures, external root resorptions, and root perforations using cone-beam computed tomography with different voxel sizes of acquisition

Aim: The aim of this study is to assess the accuracy of images acquired with cone-beam computed tomography (CBCT) in the identification of three different root alterations. Materials and Methods: Forty human premolars were allocated to four experimental groups (n = 10): sound teeth (control), vertical root fracture (VRF), external root resorption (ERR), and root perforation (RP). After the root alterations had been produced, four teeth were randomly assembled into 10 macerated mandibles and submitted to CBCT. Images were acquired with five voxel sizes (0.125, 0.200, 0.250, 0.300, and 0.400 mm) and assessed by three experienced dental radiologists. Sensitivity, specificity, positive and negative predictive values, and the areas under the receiver operating characteristic curve (accuracy) were calculated. The accuracy of imaging in different voxel sizes was compared with Tukey exact binomial test (α=5%). Results: Accuracy with voxel sizes 0.125, 0.200, and 0.250 mm was significantly higher in the detection of ERRs and VRFs than voxel sizes 0.300 and 0.400 mm. No statistical difference was found in terms of accuracy among any of the studied voxel sizes in the identification of RPs. Conclusions: Voxel size 0.125 mm produced images with the best resolution without increasing radiation levels to the patient when compared to voxel sizes 0.200 and 0.250 mm. Voxel sizes 0.300 and 0.400 mm should be avoided in the identification of root alterations.

Medicação intracanal sem trocas periódicas como tratamento de dente avulsionado: relato de caso

Posteriormente ao reimplante de dentes avulsionados existe a necessidade da realizacao do tratamento endodontico o mais breve possivel em casos diagnosticados com necrose pulpar. O protocolo de tratamento de dentes avulsionados envolve o uso de medicacao intracanal a base de hidroxido de calcio, entre sessoes, como um fator complementar a reducao de micro-organismos, prevencao e estabilizacao da reabsorcao radicular, inducao de formacao dentinaria e reparo dos tecidos periapicais. O objetivo deste trabalho e apresentar e discutir um protocolo de tratamento frente a reabsorcao radicular externa causado posteriormente ao reimplante de um dente avulsionado, por meio do uso de uma medicacao intracanal sem a necessidade de trocas periodicas. Paciente do genero masculino, 16 anos de idade, sofreu uma queda seguida de avulsao do dente 21. Relatou que o dente foi mantido em agua e reimplantado apos 10 minutos, sendo instalada uma contencao flexivel, a qual foi removida apenas quando se iniciou o tratamento endodontico, 9 meses apos o trauma. Ao exame radiografico, observou-se reabsorcao radicular externa a nivel medio e apical, portanto, foi definido o protocolo terapeutico com o uso de medicacao intracanal a base de hidroxido de calcio, associado ao propilenoglicol e oxido de zinco, a qual foi capaz de permanecer intracanal por um periodo superior a dois anos e estabilizar a reabsorcao radicular externa. Conclui-se que o reimplante dentario associado ao protocolo de tratamento utilizando esta medicacao intracanal sem trocas periodicas, possibilitou a manutencao do dente em funcionalidade e estetica, e evitou possiveis sequelas psicologicas. Descritores: Avulsao Dentaria; Reimplante Dentario; Reabsorcao da Raiz; Hidroxido de Calcio; Oxido de Zinco.

Treatment of extensive cystic lesion in the maxilla associated with dens in dente

Dens in dente is a dental development malformation that involves more commonly the upper lateral incisors. Infection of the canal of these teeth can cause the formation of chronic periapical lesions. The present study aimed to describe an integrated approach between the endodontic therapy and surgical intervention in an upper lateral incisor with dens in dente type II. A female patient, 14 years old, looked for dental care complaining of left palatal and paranasal bulging. Clinical, radiological and histopathological findings suggested periradicular cyst. First, marsupialization was performed to reduce the size of the lesion and to favor its enucleation, with less risk of injuring the tooth and vital structures. After diagnosis of pulp necrosis and in attempt to reduce the infection via canal, we used the reciprocating instrumentation associated with irrigation with sodium hypochlorite, intracanal medication based on calcium hydroxide and filled with a thermoplastic filling. After a year of marsupialization, fistulectomy and complete enucleation of the lesion were performed. Proservation was performed 1, 3, 6 and 12 months following marsupialization. Six months after enucleation, we observed the periradicular repair and remission of symptoms. The extensive apical lesion associated with dens in dente type II can be treated with a combination of surgical and endodontic therapy.