Dentistry. Implants. Dynamic loading test for endosseous dental implants

2016 ◽  
Keyword(s):  
Dental Implants ◽  
Dynamic Loading ◽  
Loading Test

scholarly journals Biomechanical Effects of Diameters of Implant Body and Implant Platform in Bone Strain around an Immediately Loaded Dental Implant with Platform Switching Concept

2019 ◽  
Vol 9 (10) ◽  
pp. 1998
Author(s):  
Hsuan Lung ◽  
Jui-Ting Hsu ◽  
Aaron Yu-Jen Wu ◽  
Heng-Li Huang
Keyword(s):  
Dental Implants ◽  
Lateral Load ◽  
Strain Gauges ◽  
Bone Strain ◽  
Vertical Load ◽  
Artificial Bone ◽  
Implant Stability ◽  
Loading Test ◽  
Platform Switching ◽  
Post Hoc

Dental implants designed with platform switching have been used clinically to reduce crestal bone resorption. The aim of this study was to determine the biomechanical effects of loading types, diameter of platform, and implant diameter in bone strain around immediately loaded implants with platform switching concept. Platform-switching features of dental implants with various diameters of implant body and implant platform (named as RP5.0, RP4.3, and NP3.5) were inserted into artificial bone blocks. The initial implant stability was confirmed using a Periotest device before the loading test. Rosette strain gauges were placed on the alveolar region around the implants, and peak values of the bone strain during a 190-N vertical load or 30-degree lateral load were measured by a data acquisition system. The Kruskal-Wallis test and post-hoc pairwise comparisons were performed as statistical analyses. The median Periotest values of the RP5.0, RP4.3, and NP3.5 implants ranged from −6.59 to −7.34. The RP5.0 implant always showed the lowest bone strain around the implant, regardless of whether a vertical or lateral load was applied. Relative to the RP4.3 and NP3.5 implants, the RP4.3 implant produced a higher bone strain (by approximately 8%) under a vertical load but a lower bone strain (by approximately 25%) under a lateral load. This study confirmed that using a wider implant could relieve the bone strain around an immediately loaded implant with platform switching concept especially under lateral loading.

Dynamic loading test and simulation analysis of full-scale semi-active hydraulic damper for structural control

2000 ◽  
Vol 29 (6) ◽  
pp. 789-812 ◽  
Author(s):  
Naoki Niwa ◽  
Takuji Kobori ◽  
Motoichi Takahashi ◽  
Hiroshi Midorikawa ◽  
Narito Kurata ◽  
...  
Keyword(s):  
Dynamic Loading ◽  
Structural Control ◽  
Simulation Analysis ◽  
Full Scale ◽  
Loading Test ◽  
Hydraulic Damper

scholarly journals Dynamic Fracture Experiment of Fractured Rock under Dynamic Loading

2020 ◽  
Vol 2020 ◽  
pp. 1-22
Author(s):  
Yanbing Wang ◽  
Xingyuan Zhou ◽  
Ji Kong ◽  
Bingbing Yu
Keyword(s):  
Mechanical Properties ◽  
Energy Loss ◽  
Dynamic Loading ◽  
Split Hopkinson Pressure Bar ◽  
Fractured Rock ◽  
Dynamic Mechanical Properties ◽  
Dynamic Crack ◽  
Loading Test ◽  
Dynamic Mechanical ◽  
The Impact

In order to examine the dynamic mechanical properties, dynamic crack proposition process, and energy loss of fractured rock under dynamic loading, the specimens with different fracture dig angles were processed with Φ50 mm × 50 mm cylindrical sandstone, the impact loading test was conducted on 50 mm stem diameter split Hopkinson pressure bar (SHPB) experiment platform, and the whole process of crack propagation and dynamic failure was recorded using a high-speed camera. As a result, the dynamic mechanical properties such as stress wave fluctuation characteristics, peak strength and stress-strain relationship, crack initiation angle, stress and other dependencies with prefabricated fracture angle of the prefabricated fracture specimens under high strain rate were obtained, and the incident energy, absorbed energy, and energy absorption rates were compared to investigate the energy loss law in the dynamic loading; on the contrary, the effects of different loading rates on the dynamic mechanical properties of the sandstone specimens were identified, and finally a set of findings were presented.

scholarly journals In Vitro Evaluation of Manual Torque Values Applied to Implant-Abutment Complex by Different Clinicians and Abutment Screw Loosening

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Onur Dincer Kose ◽  
Burcin Karataslı ◽  
Sabit Demircan ◽  
Taha Emre Kose ◽  
Erhan Cene ◽  
...  
Keyword(s):  
Dynamic Loading ◽  
Optical Microscope ◽  
Control Group ◽  
Screw Loosening ◽  
Loading Test ◽  
Torque Wrench ◽  
Implant Abutment ◽  
Torque Values ◽  
Abutment Screw

Preload is applied to screws manually or using a torque wrench in dental implant systems, and the preload applied must be appropriate for the purpose. The aim of this study was to assess screw loosening and bending/torsional moments applied by clinicians of various specialties following application of manual tightening torque to combinations of implants and abutments. Ten-millimeter implants of 3.7 and 4.1 mm diameters and standard or solid abutments were used. Each group contained five implant-abutment combinations. The control and experimental groups comprised 20 and 160 specimens, respectively. Implants in the experimental group were tightened by dentists of different specialties. Torsional and bending moments during tightening were measured using a strain gauge. Control group and implants with preload values close to the ideal preload were subjected to a dynamic loading test at 150 N, 15 Hz, and 85,000 cycles. The implants that deformed in this test were examined using an optical microscope to assess deformities. Manual tightening did not yield the manufacturer-recommended preload values. Dynamic loading testing suggested early screw loosening/fracture in samples with insufficient preload.

Development of Dynamic Loading Device for Rotating Spindle of Machine Tools

2012 ◽  
Vol 523-524 ◽  
pp. 544-549
Author(s):  
Ryota Sawamura ◽  
Shinya Ikenaga ◽  
Atsushi Matsubara
Keyword(s):  
Dynamic Loading ◽  
Machine Tools ◽  
High Speed ◽  
High Performance ◽  
Loading Rate ◽  
Electric Response ◽  
Loading Test ◽  
Loading Device ◽  
Magnetic Loading ◽  
The Magnetic Field

High performance milling spindles, which have high rigidity and high speed, are required for high productive machining. In order to evaluate the rigidity change of the spindle, authors has been developed a magnetic loading device. This device provides attractive force in radial direction to a dummy tool attached to a spindle. By using this device, the static stiffness of the rotating spindle has been successfully evaluated. However the loading rate could not be controlled due to the electric response lag caused by the magnetic field. To solve this problem, electric response of the coil-tool system with the air gap is analyzed and the dynamic response is estimated. The air-gap's influence on the load was also evaluated. Based on the analysis, a dynamic loading test is designed carried out for the measurement of the rigidity of a machine tool spindle.

Three Dimensional Seismic Isolation System for Next-Generation Nuclear Power Plant With Rolling Seal Type Air Spring and Hydraulic Rocking Suppression System

2005 ◽  
Author(s):  
Takahiro Shimada ◽  
Junji Suhara ◽  
Kazuhiko Inoue
Keyword(s):  
Dynamic Loading ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Base Isolation ◽  
Three Dimensional ◽  
Loading Test ◽  
Isolation System ◽  
Ability Test ◽  
Base Isolation System ◽  
Suppression System

Three dimensional (3D) seismic isolation devices have been developed to use for the base isolation system of the heavy building like a nuclear reactor building. The developed seismic isolation system is composed of rolling seal type air springs and the hydraulic type springs with rocking suppression system for vertical base isolation device. In horizontal direction, the same laminated rubber bearings are used as horizontal isolation device for these systems. The performances and the applicability have already been evaluated by the technical feasibility tests and performance tests for each system. In this study, it was evaluated that the performance of the 3D base isolation system with rolling seal type air springs combined with hydraulic rocking suppression devices. A 1/7 scaled model of the 3D base isolation devices were manufactured and some performance test were executed for each device. For the rolling seal type air springs, dynamic loading test was executed with a vibration table, and pressure resistant ability test was executed for reinforced air springs. In the dynamic loading test, it is confirmed that the natural period and damping performance were verified. In the pressure resistant ability test, it is confirmed that the air springs had sufficient strength. For the hydraulic rocking suppression system, forced dynamic loading test was carried out in order to measure the frictional and oil flow resistance force on each cylinder. And the vibration table tests were carried out with supported weight of 228 MN in order to evaluate and to confirm the horizontal and vertical isolation performance, rocking suppression performance, and the applicability of the this seismic isolation system as the combined system. 4 rolling seal type air springs and 4 hydraulic load-carrying cylinders with rocking suppression devices supported the weight. As a result, the proposed system was verified that it could be applied to the actual nuclear power plant building to be target.

scholarly journals DYNAMIC LOADING TEST ON RC FRAME EXTERNALLY RETROFITTED BY CES FRAME

2008 ◽  
Vol 73 (630) ◽  
pp. 1265-1272 ◽  
Author(s):  
Hiroshi KURAMOTO ◽  
Ryosuke HAGA ◽  
Tomoya MATSUI ◽  
Takashi TAGUCHI
Keyword(s):  
Dynamic Loading ◽  
Rc Frame ◽  
Loading Test

A dynamic loading system for high-speed motorized spindle with magnetorheological fluid

2018 ◽  
Vol 29 (13) ◽  
pp. 2754-2765 ◽  
Author(s):  
Shengli Tian ◽  
Xiaoan Chen ◽  
Ye He ◽  
Tianchi Chen ◽  
Peiming Li
Keyword(s):  
Dynamic Loading ◽  
High Speed ◽  
Dynamic Performance ◽  
Temperature Stability ◽  
Magnetorheological Fluid ◽  
Experimental Results ◽  
Motorized Spindle ◽  
Loading Test ◽  
Linear Relationships ◽  
Loading System

A high-speed dynamic loading test is a key step when testing the dynamic performance and running quality of a high-speed motorized spindle. A loading test is very difficult to perform at high speeds. Based on the rheological behavior of the magnetorheological fluid, a novel high-speed dynamic loading system for a high-speed motorized spindle was designed, fabricated, and tested. The working principles and structure of this loading system are described. The torque model of the loader was derived based on the Herschel–Bulkley model and electromagnetic simulation using the finite element method. In addition, the torque–current relationship under different speeds was analyzed by experiments, and we found non-linear relationships between the viscosity and shear stress of the magnetorheological fluid with the shear rate. The Herschel–Bulkley model was corrected by fitting for the experimental results. The loading torque, calculated by the modified model, complied with the experimental results. This lays the foundation for the design of a high-speed transmission device based on the magnetorheological shear principle. Experiments of torque stability, temperature stability, and reusability verified the feasibility and accuracy of the proposed loading system. It provides a novel method to test the dynamic loading performance of high-speed motorized spindles.

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