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Numerous studies have previously evaluated the marginal and internal fit of fixed prostheses; however, few reports have performed an objective comparison of the various methods used for their assessment. The purpose of this study was to compare five marginal and internal fit assessment methods for fixed prostheses. A specially designed sample was used to measure the marginal and internal fit of the prosthesis according to the cross-sectional method (CSM), silicone replica technique (SRT), triple scan method (TSM), micro-computed tomography (MCT), and optical coherence tomography (OCT). The five methods showed significant differences in the four regions that were assessed (p < 0.001). The marginal, axial, angle, and occlusal regions showed low mean values: CSM (23.2 µm), TSM (56.3 µm), MCT (84.3 µm), and MCT (102.6 µm), respectively. The marginal fit for each method was in the range of 23.2–83.4 µm and internal fit (axial, angle, and occlusal) ranged from 44.8–95.9 µm, 84.3–128.6 µm, and 102.6–140.5 µm, respectively. The marginal and internal fit showed significant differences depending on the method. Even if the assessment values of the marginal and internal fit are found to be in the allowable clinical range, the differences in the values according to the method should be considered.

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This paper presents a magnetic resonance wireless power transfer (WPT) system that uses three coils, a planar receiver and operates at 6.78 MHz,. Effective power transfer is ensured by establishing an impedance matching condition for this WPT system. A metamaterial (MTM) array having dimensions of 20 cm. 30 cm is also positioned near the load coil to concentrate the magnetic field and enhance the transfer efficiency. The result is a maximal improvement of 27% in the transfer efficiency at a transfer distance of 50 cm. The impact of a ground plane on the transfer efficiency is also examined. By utilizing the MTM array, making slits on the ground plane and increasing the gap between the ground plane and the load coil, it is possible to mitigate this impact. The highest transfer efficiency improvement is about 55% at a distance of 20 cm with the ground plane. A practical laptop model is fabricated to verify the impact of the load coil angle and position on the transfer efficiency. The result shows that the maximum transfer efficiency with the laptop model is 47.58% with the load coil angle of 90 degree(1)

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This study presents the design and analysis of a magnetic resonant coupling wireless power transfer (MR‐WPT) system that employs planar textile resonators. To reduce the size of the system for wearable applications, the transmitter and receiver are designed and fabricated on a flat plane of fabric. A proposed symmetric four‐resonator MR‐WPT system is used for verifying the electromagnetic property of the textile substrates. Two textile substrates: polyester and cotton fibre are investigated to determine their impact on the transfer efficiency. Experiments show that the transfer efficiency is considerably higher with the polyester substrate than with the cotton substrate. In addition, copper tape and silver paste are employed for the resonator fabrication because of their flexibility. The measured results show that the copper tape has a significantly higher transfer efficiency than the silver paste because of its high conductivity. At a transfer distance of 5 cm, the maximum transfer efficiency is 50% with the polyester substrate and the copper tape resonator. Furthermore, the width of the coil‐pattern is varied to determine its impact on the resonant frequency and the transfer efficiency of the MR‐WPT system. This research confirms the feasibility of using flexible MR‐WPT for wearable applications.