Background. Peri-implant soft tissue health and esthetic is one of the main factors influencing the longterm survival and success of implants. While platform-switched (PS) implants have been widely studied in terms of marginal bone preservation, the purpose of this study is to review the soft tissue conditions around these implants. Methods. Using pertinent keywords, PubMed and Embase databases were searched for relevant clinical studies which compared the peri-implant soft tissue outcomes of PS implants to the implants with matching diameter abutments. The quality of articles was evaluated using Cochrane Collaboration’ s tool for randomized controlled trials and Methodological Index for Non-Randomized Studies. Results. Eight clinical studies were selected to be reviewed. The articles varied in numerous features such as the implants’ brands, the duration of follow-up and the study quality. The evaluated peri-implant soft tissue parameters included the height or recession in buccal mucosa, height of the mesial and distal papilla, the mucosal thickness, and pink esthetic score. In all studies, PS implants showed better or at least similar results relative to the implants with flat-to-flat or conical connections. The difference between the test and control groups reached statistical significance in three of the reviewed articles. Conclusions. PS implants can provide peri-implant soft tissue health and stability and consequently acceptable clinical results.

switching supervisory is the most important section of a feedback control process in MIMO hybrid systems. By choosing a non-compatible controller, system may go to unstable mode or high overshoot response. In this paper, a new method of switching for selecting MBC controllers is discussed. Results of the simulation show the MIMO (2-in 2-out) linear hybrid system can be switched stable and low overshooting in switching time. This method can be expanded to nonlinear MIMO systems.

In this paper, a novel structure and a control method to improve the performance of inductive heating circuits is proposed. In the presented structure, with the combination of the performance of a half-bridge resonant converter with voltage-boost capability, the reduction in output efficiency at low power and at high power is compensated to an acceptable level. The use of the low number of switches and diodes, the use of the high-quality capacitors with low capacities, good quality of the input current and also high power factor ensures the proper operation of the proposed converter. The switching of high frequency switches in the proposed structure is carried out as soft-switching where resulting in very low switching losses. In this converter, the design of the input filter in order to prevent the effects of electromagnetic interference has been prepared. Finally, to demonstrate the proposed structure operation, the simulation and experimental results are presented.

In this paper, a non-isolated current-fed high step-up soft-switching converter, is presented. In proposed converter are used of 2-stge switched capacitor and a soft switching active cell. Compared to its high step-up counterpart, the proposed converter has a higher voltage gain. In this converter, an active clamp circuit is used to absorb the energy of leakage inductor, therefore, the ZVS for switches. Also, voltage stresses on the switches are low. In this paper, the operational principle and characteristics of proposed converter are presented, and in order to verify the proposed converter, a 20-400V, 200W prototype converter is simulated and implemented and experimental results are provided.

In this paper, a new high step-up current-fed LLC resonant DC-DC converter with a center-tapped transformer is proposed. By selecting the switching frequency to be lower than, but near to, the series resonant frequency of the LLC resonant tank, soft-switching operation of all semiconductors, i.e., zero voltage switching (ZVS) turn-on of power MOSFETs and zero current switching (ZCS) turn-off of diodes is achieved. This leads to lower electromagnetic interference (EMI) and lower switching losses and improves the converter efficiency. An interleaved structure is used at the primary side. Thus, input current ripple is smaller, and its frequency is twice the switching frequency. Consequently, a smaller input filter is necessary in practice. The converter with 1.2 kW output power and 760 V regulated output voltage with 80-200 V input voltage variations is simulated. The output voltage is regulated by using asymmetric pulse width modulation (APWM) at 200 kHz switching frequency. Finally, a 700-W prototype has been implemented and experimental results are also presented to verify the simulation results.

In this paper, a non-isolated high step-up soft-switching converter is proposed. The proposed converter is a boost converter combined with two voltage multiplier cells for boosting output voltage. Also, extend voltage gain of the proposed converter is achieved by using a coupled-inductor. Compare with other similar high step-up topologies with the same number of components, the proposed converter has a higher voltage gain and higher efficiency. An active clamp circuit is used so, the zero-voltage switching (ZVS) is achieved. Also, in the proposed converter, the voltage stresses on the switches are low. As the voltage stress decreases on the switch, Ron of the MOSFET is deceased and as a result conduction loss of the switch is decreased. So, the efficiency of this converter increased. In this paper, operational principle of the converter is described and the analytical, simulated results and prototype converters are validated using a 20V input and 400V output converter at 200W load.

In this paper, a new soft switching boost converter is presented. A lossless active snubber circuit including an auxiliary switch, three diodes, a capacitor and a coupled-inductor provides soft switching conditions for the main switch and the output diode, so that the main switch and the output diode operate under ZCS and ZVS conditions, respectively. They turn on and off under the ZCS condition. The operation of the snubber circuit is associated with low current stress on the main switch and low current and voltage stress on the output diode. The proposed converter is able to maintain the smooth switching condition in a wide range of output load and input voltage variations. Working principles, steady state analysis and design procedure of this converter are discussed in detail. Also, to confirm the theoretical results, a laboratory sample is made and tested. It should be noted that, The laboratory results confirm the theoretical results comprehensively.

The interleaved boost converters are the power circuits that provide high-voltage, high-power with regulated output voltage for renewable energy systems which are generally suffer from low-voltage and unregulated output voltages. The soft switching methods reduce electromagnetic noises and switching losses in these converters. In this paper, a ZVT interleaved boost converter with a simple auxiliary circuit is proposed. The proposed converter has a simple structure with low size and cost. In the proposed converter, soft switching condition is provided without any extra voltage and current stress on the main switches. The auxiliary circuit comprises two diodes and one auxiliary switch. The leakage inductance of the utilized coupled inductors is used as resonant inductor. The auxiliary switches benefit from significantly reduced voltage stress without requiring floating gate driver. The proposed converter can achieve zero voltage switching operation for the main switches and zero current switching for diodes and auxiliary switches, which causes to alleviate the reverse recovery problems of all diodes.