RESUMO
OBJECTIVES: To explore the method of manufacturing an implant surgery template with a computer-aided design/computer-aided manufacturing (CAD/CAM) technique and evaluate its precision in clinical cases. METHODS: Patients referred to the 2nd Dental Center of Peking University who were partially edentulous, were enrolled and scanned with cone beam computed tomography (CBCT). Diagnostic casts were laser scanned to record the configuration of the patients' dentition and mucosae. CBCT and laser scanning data were subsequently loaded into Simplant software. Implant positions were planned in the software with a computer-aided design technique, and surgical templates were fabricated with a rapid prototyping technique. These templates were used to guide implant placement surgery. RESULTS: The mean value of linear deviation was 1.00 mm (range 0 to 2.16 mm) for implant shoulder and 1.26 mm (range 0.51 to 2.86 mm) for the implant apex. The mean angular deviation was 4.74 degress (0.37 to 10.28 degrees). Deviations were higher in the posterior region than anterior. The tooth-supported template provided higher precision than did the tooth/ mucosa-supported template, but no statistically significant difference was found. CONCLUSION: Computer-guided implant surgery with the CAD/CAM technique provides dentists with a good platform for preoperative planning, precise implant insertion, and ideal rehabilitation. The protocol of this three-dimensional laser scanning technique can provide precision comparable to that of double-scanning.
Assuntos
Desenho Assistido por Computador/normas , Implantação Dentária Endóssea/normas , Lasers , Cirurgia Assistida por Computador/normas , Adulto , Idoso , Transplante Ósseo/métodos , Tomografia Computadorizada de Feixe Cônico/métodos , Implantação Dentária Endóssea/instrumentação , Implantação Dentária Endóssea/métodos , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador/normas , Imageamento Tridimensional/métodos , Imageamento Tridimensional/normas , Arcada Parcialmente Edêntula/reabilitação , Arcada Parcialmente Edêntula/cirurgia , Masculino , Pessoa de Meia-Idade , Modelos Dentários , Imagem Multimodal/métodos , Planejamento de Assistência ao Paciente , Software , Cirurgia Assistida por Computador/métodos , Interface Usuário-ComputadorRESUMO
OBJECTIVE: To evaluate the effects of magnetic attachment keepers on MRI images. METHODS: In in vitro part, keepers of MAGFIT EX 400, MAGFIT EX 600 and MAGNEDISC 800 magnetic attachment systems were cast into standard root-caps with different alloy respectively, including nickel-chromium alloy and gold-palladium alloy, or not be cast for contrast. In in vivo part, volunteers with keepers in different position and amount were included. All the specimens and volunteers were imaged by a Siemens SONATA 1.5-T MRI scanner. Extent of the artifacts in every slice was measured. The magnitude of the artifacts and the distortion of the anatomic structures were compared. RESULTS: All kinds of keepers being studied produced obvious MRI artifacts. The extent of MRI artifacts induced by MAGFIT EX 400 keepers, MAGFIT EX 600 keepers and MAGNEDISC 800 keepers are 158.94 mm, 168.52 mm and 173.00 mm, respectively. The images of mental region, tongue, palate, jawbone and sinus were evidently obscured by artifacts in all cases. When keeper was put in the molar region, the keeper-related MRI artifact may obscure the imaging of brain, spinal cord. SE sequence with right-left frequency-encoding direction was more desirable in MRI for the patients with magnetic attachment keepers. CONCLUSION: Keepers of magnetic attachment system did induce obvious artifacts in MRI examination.
