scholarly journals Biomechanical Analysis of Individual All-Ceramic Abutments Used in Dental Implantology

2016 ◽  
Vol 61 (3) ◽  
pp. 1357-1362 ◽  
Author(s):  
B. Ziębowicz ◽  
A. Ziębowicz ◽  
B. Bączkowski ◽  
W. Kajzer ◽  
A. Kajzer
Keyword(s):  
Cyclic Load ◽  
Experimental Testing ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Biomechanical Analysis ◽  
Element Analysis ◽  
Physiological Loading ◽  
All Ceramic ◽  
Cad Cam ◽  
Iso 14801

Abstract The paper presents the results of finite element analysis and experimental testing under simulated physiological loading conditions on issues shaping the functional properties of individual all-ceramic abutments manufactured by CAD/CAM technology. The conducted research have cognitive significance showing the all-ceramic abutment behavior, as a key element of the implantological system, under the action of cyclic load. The aim of this study was evaluation the fatigue behavior of yttria-stabilized zirconia abutment submitted to cyclic stresses, conducted in accordance with EN ISO 14801 applies to dynamic fatigue tests of endosseous dental implants.

scholarly journals Comparison of Different Cervical Finish Lines of All-Ceramic Crowns on Primary Molars in Finite Element Analysis

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1094 ◽  
Author(s):  
Chin-Yun Pan ◽  
Ting-Hsun Lan ◽  
Pao-Hsin Liu ◽  
Wan-Ru Fu
Keyword(s):  
Finite Element ◽  
Maximum Stress ◽  
Primary Root ◽  
Biomechanical Analysis ◽  
Primary Tooth ◽  
Finish Line ◽  
Element Analysis ◽  
All Ceramic ◽  
Ceramic Crowns ◽  
Loading Type

This study aimed to conduct a stress analysis of four types of cervical finish lines in posterior all-ceramic crowns on the primary roots of molar teeth. Four different types of finish lines (shoulder 0.5 mm, feather-edged, chamfer 0.6 mm, and mini chamfer 0.4 mm) and two all-ceramic crown materials (zirconia and lithium disilicate) were used to construct eight finite element primary tooth models with full-coverage crowns. A load of 200 N was applied at two different loading angles (0° and 15°) so as to mimic children’s masticatory force and occlusal tendency. The maximum stress distribution from the three-dimensional finite element models was determined, and the main effect of each factor (loading type, material, and finish line types) was evaluated in terms of the stress values for all of the models. The results indicated that the loading type (90.25%) was the main factor influencing the maximum stress value of the primary root, and that the feather-edged margin showed the highest stress value (p = 0.002). In conclusion, shoulder and chamfer types of finish lines with a 0.4–0.6 mm thickness are recommended for deciduous tooth preparation, according to the biomechanical analysis.

Biomechanical analysis of spinal implants with different rod diameters under static and fatigue loads: an experimental study

2019 ◽  
Vol 64 (3) ◽  
pp. 339-346 ◽  
Author(s):  
Halim Kovacı ◽  
Ali Fatih Yetim ◽  
Ayhan Çelik
Keyword(s):  
Dynamic Compression ◽  
Fatigue Behavior ◽  
Pedicle Screws ◽  
Fatigue Tests ◽  
Biomechanical Analysis ◽  
Static Tension ◽  
Test Results ◽  
Spinal Implants ◽  
Biomechanical Behavior ◽  
Load Carrying

Abstract Spinal implants are commonly used in the treatment of spinal disorders or injuries. However, the biomechanical analyses of them are rarely investigated in terms of both biomechanical and clinical perspectives. Therefore, the main purpose of this study is to investigate the effects of rod diameter on the biomechanical behavior of spinal implants and to make a comparison among them. For this purpose, three spinal implants composed of pedicle screws, setscrews and rods, which were manufactured from Ti6Al4V, with diameters of 5.5 mm, 6 mm and 6.35 mm were used and a bilateral vertebrectomy model was applied to spinal systems. Then, the obtained spinal systems were tested under static tension-compression and fatigue (dynamic compression) conditions. Also, failure analyses were performed to investigate the fatigue behavior of spinal implants. After static tension-compression and fatigue tests, it was found that the yield loads, stiffness values, load carrying capacities and fatigue performances of spinal implants enhanced with increasing spinal rod diameter. In comparison to spinal implants with 5.5 mm rods, the fatigue limits of implants showed 13% and 33% improvements in spinal implants having 6 mm and 6.35 mm rods, respectively. The highest static and fatigue test results were obtained from spinal implants having 6.35 mm rods among the tested implants. Also, it was observed that the increasing yield load and stiffness values caused an increase in the fatigue limits of spinal implants.

Low-Cycle Fatigue Behavior of Small Slice Specimens of Zircaloy-4 at Elevated Temperature

2006 ◽  
Vol 324-325 ◽  
pp. 1241-1244 ◽  
Author(s):  
Li Xun Cai ◽  
Yu Ming Ye
Keyword(s):  
Elevated Temperature ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cyclic Hardening ◽  
Cyclic Softening ◽  
Fatigue Tests ◽  
Uniaxial Strain ◽  
Transverse Strain ◽  
Test Results ◽  
Element Analysis

A series of strain fatigue tests were carried out on small bugle-like slice-specimens of Zr-4 alloy at 20 and 400. According to Elastic and Plastic Finite Element Analysis and assumption of local damage equivalence, a strain formula was given to transform transverse strain of the specimen to uniaxial strain. Based on the test results of the alloy and the strain transform formula, M-C (Manson-Coffin) models to be used for estimating uniaxial fatigue life of Zr-4 alloy were obtained. The results show that, the alloy mainly behaves as cyclic softening at 20 and as cyclic hardening at 400, and the elevated temperature can lead serious additional fatigue damage of the alloy and the effect of the elevated temperature impairs gradually with increasing of amplitude strain. A conclusion is helpful that prediction life by using M-C model based on traditional strain transform equation is quite conservative when uniaxial strain amplitude is less than 0.5%.

Investigation into Tangential Force and Axial Stress Effects on Fretting Fatigue Behavior

2005 ◽  
Vol 128 (2) ◽  
pp. 202-209 ◽  
Author(s):  
Hyukjae Lee ◽  
Shankar Mall
Keyword(s):  
Phase Difference ◽  
Cyclic Load ◽  
Fatigue Behavior ◽  
Axial Stress ◽  
Tangential Force ◽  
Fretting Fatigue ◽  
Fatigue Tests ◽  
Partial Slip ◽  
Relative Slip ◽  
Force Range

Fretting fatigue behavior of a titanium alloy was investigated using a dual actuator test setup which was capable to apply the pad displacement independent of the applied cyclic load on specimen. Fretting fatigue tests were conducted using this setup with a phase difference between cyclic load on the specimen and tangential force on the fretting pad with cylinder-on-flat contact configuration under partial slip condition. Two axial stress ratios were used. The relative slip range and tangential force range were related to each other and this relationship was not influenced by phase difference, axial stress ratio, and contact load under the partial slip condition. Change in the phase difference caused the change in relative slip as well as tangential force for a given applied pad displacement and axial load. However, there was no effect of phase difference on fretting fatigue life at a given relative slip level. Fretting fatigue tests with a fully reversed axial stress showed longer fatigue life than tension-tension counterparts at a given relative slip, tangential force range, and axial stress range. Finite element analysis was conducted by including the complete load history effects, which showed that stress distribution on the contact surface stabilized after the first fatigue cycle. Unlike relative slip and∕or tangential force range, a critical plane-based parameter appears to take into account the stress ratio effects to characterize fretting fatigue behavior.

Influence of superstructure geometry on the mechanical behavior of zirconia implant abutments: a finite element analysis

2014 ◽  
Vol 59 (6) ◽  
Author(s):  
Alexander Geringer ◽  
Stefan Diebels ◽  
Frank P. Nothdurft
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Mechanical Behavior ◽  
Clinical Performance ◽  
Fatigue Tests ◽  
Point Of View ◽  
Fe Model ◽  
Element Analysis ◽  
Implant Abutment ◽  
Iso 14801

AbstractTo predict the clinical performance of zirconia abutments, it is crucial to examine the mechanical behavior of different dental implant-abutment connection configurations. The international standard protocol for dynamic fatigue tests of dental implants (ISO 14801) allows comparing these configurations using standardized superstructure geometries. However, from a mechanical point of view, the geometry of clinical crowns causes modified boundary conditions. The purpose of this finite element (FE) study was to evaluate the influence of the superstructure geometry on the maximum stress values of zirconia abutments with a conical implant-abutment connection. Geometry models of the experimental setup described in ISO 14801 were generated using CAD software following the reconstruction of computerized tomography scans from all relevant components. These models served as a basis for an FE simulation. To reduce the numerical complexity of the FE model, the interaction between loading stamp and superstructure geometry was taken into account by defining the boundary conditions with regard to the frictional force. The results of the FE simulations performed on standardized superstructure geometry and anatomically shaped crowns showed a strong influence of the superstructure geometry and related surface orientations on the mechanical behavior of the underlying zirconia abutments. In conclusion, ISO testing of zirconia abutments should be accompanied by load-bearing capacity testing under simulated clinical conditions to predict clinical performance.

scholarly journals Fatigue Design of Dental Implant Assemblies: A Nominal Stress Approach

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 744 ◽  
Author(s):  
Mikel Armentia ◽  
Mikel Abasolo ◽  
Ibai Coria ◽  
Joseba Albizuri
Keyword(s):  
Dental Implants ◽  
Dental Implant ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Experimental Tests ◽  
Design Tool ◽  
Nominal Stress ◽  
Fe Model ◽  
Element Analysis ◽  
Iso 14801

Fatigue is the most common mechanical failure type in dental implants. ISO 14801 standardizes fatigue testing of dental implants, providing the load-life curve which is most useful for comparing the fatigue behavior of different dental implant designs. Based on it, many works were published in the dental implant literature, comparing different materials, component geometries, connection types, surface treatments, etc. These works are useful for clinicians in order to identify the best options available in the market. The present work is intended not for clinicians but for dental implant manufacturers, developing a design tool that combines Finite Element Analysis, fatigue formulation and ISO 14801 experimental tests. For that purpose, 46 experimental tests were performed on BTI INTERNA® IIPSCA4513 implants joined with INPPTU44 abutments by means of INTTUH prosthetic screws under three different tightening torque magnitudes. Then, the load case was reproduced in a FE model from where the nominal stress state in the fatigue critical section was worked out. Finally, Walker criterion was used to represent accurately the effects of mean stress and predict fatigue life of the studied dental implant assembly, which can be extended to most of the products of BTI manufacturer. By means of this tool, dental implant manufacturers will be able to identify the critical design and assembly parameters in terms of fatigue behavior, evaluate their influence in preliminary design stages and consequently design dental implants with significantly better fatigue response which in turn will reduce future clinical incidences.

Fatigue resistance of all-ceramic fixed partial dentures – Fatigue tests and finite element analysis

2018 ◽  
Vol 34 (3) ◽  
pp. 494-507 ◽  
Author(s):  
S.D. Heintze ◽  
D. Monreal ◽  
M. Reinhardt ◽  
A. Eser ◽  
A. Peschke ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Resistance ◽  
Fatigue Tests ◽  
Element Analysis ◽  
All Ceramic

scholarly journals Fatigue Analysis of Threaded Components with Cd and Zn-Ni Anticorrosive Coatings

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1455
Author(s):  
Jefferson Rodrigo Marcelino dos Santos ◽  
Martin Ferreira Fernandes ◽  
Verônica Mara de Oliveira Velloso ◽  
Herman Jacobus Cornelis Voorwald
Keyword(s):  
Stress Concentration ◽  
Stress Ratio ◽  
Fatigue Behavior ◽  
Base Material ◽  
Experimental Tests ◽  
Fatigue Tests ◽  
Element Analysis ◽  
Aisi 4140 ◽  
Stress Concentration Effect ◽  
Zinc Nickel

The influence of the electrodeposition of cadmium and zinc-nickel and the stress concentration effect on the fatigue behavior of AISI 4140 steel threaded components were studied. Axial fatigue tests at room temperature with a stress ratio of R = 0.1 were performed using standard and threaded specimens with and without nut interface under base material, cadmium, and zinc-nickel-coated conditions. Finite element analysis (FEA) was used, considering both elastic and elastoplastic models, to quantify the stress distribution and strain for threaded specimens with and without a nut interface. The numeric results were correlated to the experimental fatigue data of threaded components with and without the nut interface, to allow the oil & gas companies to extrapolate the results for different thread dimensions, since the experimental tests are not feasible to be performed for all thread interfaces. Scanning electron microscopy (SEM) was used to analyze the fracture surfaces. The stress concentration factor had a greater influence on the fatigue performance of threaded components than the effect of the Cd and Zn-Ni coatings. The fatigue life of studs reduced by about 58% with the nut/stud interface, compared to threaded components without nuts. The elastoplastic FEA results showed that studs with a stud/nut interface had higher stress values than the threaded specimens without a nut interface. The FEA results showed that the cracks nucleated at the regions with higher strain, absorbed energy, and stress concentration. The substitution of Cd for a Zn-Ni coating was feasible regarding the fatigue strength for threaded and smooth components.

Fatigue Evaluation of 8630 Cast Steel Subjected to Post-Weld Heat Treatment and Stress Relieving

2014 ◽  
Author(s):  
Alireza Shirazi ◽  
Ihab Ragai
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Fatigue Behavior ◽  
Cast Steel ◽  
Fatigue Tests ◽  
Filler Materials ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Stress Relieving ◽  
Weld Heat

The effect of post weld heat treating and stress relieving on the fatigue strength of AISI 8630 cast steel, weld repaired with different filler materials, is the primary objective of the study. To determine the material properties, experiments included monotonic tensile tests, load-controlled fatigue tests as well as hardness tests. Moreover, specimens were micro-etched to examine the morphology of the fracture surface. The results of the fatigue tests are presented in the form of S-N charts. The test findings are then employed in a generalized numerical solution to predict the fatigue behavior of similar components. Finite element models are used to calculate stresses in tested samples, stress concentrations, and in fatigue life comparisons. Stress-life predictions were performed using the modified Goodman criterion to account for the mean stress effects caused by the stress ratio R = 0.1 loading. Predictions based off of finite element analysis and analytical solution for fatigue life provided reasonable estimates which are confirmed by the experimental results.

scholarly journals Mechanical Performance of Chairside Ceramic CAD/CAM Restorations and Zirconia Abutments with Different Internal Implant Connections: In Vitro Study and Finite Element Analysis

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5009
Author(s):  
Sergio Giner ◽  
José F. Bartolomé ◽  
Pablo Gomez-Cogolludo ◽  
Carlos Castellote ◽  
Guillermo Pradíes
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Fatigue Test ◽  
Mechanical Performance ◽  
Element Analysis ◽  
All Ceramic ◽  
Computer Aided ◽  
Conical Connection ◽  
Cad Cam

(computer-aided design-computer-aided manufacturing) CAD/CAM monolithic restorations connected to zirconia abutments manufactured with a chairside workflow are becoming a more common restorative option. However, their mechanical performance is still uncertain. The aim of this study was to evaluate the mechanical behavior of a combination of a zirconia abutment and monolithic all-ceramic zirconia and lithium disilicate crown manufactured with a chairside workflow, connected to titanium implants with two types of internal connection—tube in tube connection and conical connection with platform switching. They were thermally cycled from 5 °C to 55 °C and were subjected to a static and fatigue test following ISO 14801. The fractured specimens from the fatigue test were examined by SEM (scanning electron microscopy). Simulations of the stress distribution over the different parts of the restorative complex during the mechanical tests were evaluated by means of (finite element analysis) FEA. The mechanical performance of the zirconia abutment with an internal conical connection was higher than that of the tube in tube connection. Additionally, the use of disilicate or zirconia all-ceramic chairside CAD/CAM monolithic restorations has similar results in terms of mechanical fracture and fatigue resistance. Stress distribution affects the implant/restoration complex depending on the connection design. Zirconia abutments and monolithic restorations seem to be highly reliable in terms of mechanical resistance.

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