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Navegando PPGCO - Dissertações de Mestrado por Assunto "Adaptação marginal dentária"
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- ItemAcurácia de quatro técnicas radiográficas intrabucais na detecção de desadaptação entre implante e componente protético(Universidade Federal do Espírito Santo, 2017-03-17) Darós, Pollyana; Vaz, Sérgio Lins de Azevedo; Silva, Daniela Nascimento; Paula, Vitor Guarçoni deMisfit at implant-abutment joints (IAJ) may compromise the perimplant tissues health. Intraoral radiograph are an complementary diagnostic method to misfit detection and an orthogonal relation between the central beam, the implant, and the radiographic film is indicated. The aim of this study evaluated the accuracy of 4 intraoral radiographic techniques on the detection of gaps at IAJ. Twenty implants were placed in prototyped jaws and UCLA-type abutments with metal collar were installed. Different gaps were simulated by placing one or three 50-μm-thickness polyester strips at the IAJ, and the absence of the strip represented the control group (no gap). Periapical radiographs with different film-holders were taken for each technique: bisecting, interproximal, parallel-cone and modified-parallel-cone (with a custommade paralleling index). A total of 240 digital radiographs were evaluated by 4 specialists in dental implants. The ROC curves (Az) and Fisher’s Exact comparison tests were performed at a significance level of 5%. Diagnostic values (sensitivity, specificity, accuracy, positive, and negative predictive values) were also obtained. The Kappa test was used to assess intra- and inter-evaluator reproducibility, which ranged from substantial to almost perfect, and moderate to substantial, respectively. All diagnostic values were lower for the bisecting technique for both 50- and 150-μm gaps. Az values for the bisecting technique were significantly lower than those obtained for the other 3 techniques (p<.05), which did not differ from each other. The 150-μm gaps were more easily detected than 50-μm gaps only for the bisecting technique (p˂.05). The interproximal, parallel-cone and, modified-parallel-cone techniques were the most accurate to detect misfits at IAJ. The bisecting technique should not be clinically indicated for this purpose.
- ItemAvaliação da acurácia da tomografia computadorizada de feixe cônico no diagnóstico de desadaptação de próteses sobre implante confeccionadas em diferentes materiais(Universidade Federal do Espírito Santo, 2018-09-25) Siqueira, Caíque Araujo; Azeredo, Rogério Albuquerque; Vaz, Sérgio Lins de Azevedo; Ferreira, Liana Matos; Zanon, Juliana MalacarneIntroduction: Dental implants are increasingly used after teeth loss to rehabilitate function and aesthetics. A prosthesis is installed over the implant and can be manufactured in several materials. The prosthesis must be well adapted to the implant since misfits may cause an increase in the prosthetic tension values. In order to detect misfits at the prosthesis-implant interface, radiographic and tactile examinations may be used. However, they are susceptible to the operator and the technique used, besides the radiographic examination provides a twodimensional image. Cone beam computed tomography (CBCT) produce three-dimensional images, but studies are lacking to evaluate its performance in the follow-up of implants. Materials with high atomic number and physical density which are used to manufacture implant-supported prostheses may negatively influence the quality of the tomographic image and the diagnosis. Objective: To evaluate the accuracy of CBCT in the detection of misfits at the prosthesis-implant interface with prostheses manufactured in different materials. Material and Methods: 32 external hexagon implants were installed in dried human mandibular jaws. Prostheses of different materials were installed over these implants, constituting 3 experimental groups: porcelain-fused-to-metal, titanium covered by resin, and zirconia covered by ceramics. Misfits were simulated by interposing polyester strips between implant and prostheses. Tomographic images of the mandibles were acquired using the Picasso Trio (85 kVp, 10 mA, FOV 8x5cm and Voxel 0.2mm) with and without the simulated misfits. Five dentists evaluated the images to verify the presence or absence of simulated misfits. The analyses of intra- and inter-reproducibilities were performed using the Kappa test. Descriptive analyses were performed to determine diagnostic values and the values of areas under the ROC curve (Az) were calculated. Results: Intra- and inter-reproducibilities ranged from fair to almost perfect. The highest values of sensitivity, accuracy, positive predictive value and negative predictive value were found for the Titanium group. The largest Az were found for the Titanium (Az = 0.95) and Porcelain-fused-to-metal (Az = 0.90) groups, and the smallest for the Zirconia group (Az = 0.77), with statistically significant differences between Zirconia and Titanium, and Zirconia and Porcelain-fused-to-metal (p <0.05) groups. Conclusion: The detection of misfits at the prosthesis-implant interface through CBCT has a greater accuracy for titanium prostheses coated with resin and porcelain-fused-to-metal.
- ItemAvaliação da acurácia em detectar a desadaptação entre implante e prótese por meio de tomografia computadorizada de feixe cônico(Universidade Federal do Espírito Santo, 2018-05-18) Carneiro, Vinícius Cavalcanti; Azeredo, Rogério Albuquerque; Vaz, Sérgio Lins de Azevedo; Ferreira, Liana Matos; Guimarães, Jackeline CoutinhoIntroduction: the long-term success of osseointegration and implant-supported prostheses is achieved through the fit between abutment and implant platform, which also figure as a requirement for maintance of bone-implant inferface. In cases where the adaptation is not effective, misfits at the implant-abutment joint (IAJ) might be present. Periapical radiographs are often used as a complementary method for misfit detection; however, there are limited evidences that support the use of imaging methods to evaluate the IAJ. Objective: to evaluate the accuracy of three cone beam computed tomography CBCT systems for misfit detection at the IAJ. Method: 32 implants were placed in the region of molars and premolars of eight dried human mandibular jaws. Polyester strips were placed between the implant platforms and porcelain-fused-to-metal crowns in order to simulate gaps of 200-μm, while no strips were placed in the control group (0 μm). Next, specimens were scanned in both conditions, with and without simulated gap, by using the CBCT systems Picasso Trio, OP300 and Scanora 3D. CBCT images were assessed by four evaluators regarding the presence or absence of misfit at IAJ. The contrast resolution of the images was measured by an independent evaluator with the aid of ImageJ software. Statistical analysis included the calculation of diagnostic values, comparison among values of areas under the ROC curves (Az) and Kappa test. Results: intra- and interreproducibility ranged from fair to almost perfect and were lower for OP300 and Scanora 3D. Picasso Trio showed higher diagnostic values (accuracy = 0.84, sensitivity = 0.83, specificity = 0.85, positive predictive value = 0.85, negative predictive value = 0.84) and Az (0.86; p<.05). Picasso Trio obtained higher contrast resolution than OP300 and Scanora 3D systems. Conclusion: in comparison to OP300 and Scanora 3D systems, images acquired with Picasso Trio allowed a more accurate misfit detection at IAJ.