scholarly journals Stress shielding at the bone‐implant interface: Influence of surface roughness and of the bone‐implant contact ratio

2020 ◽  
Author(s):  
Maria Letizia Raffa ◽  
Vu‐Hieu Nguyen ◽  
Philippe Hernigou ◽  
Charles‐Henri Flouzat‐Lachaniette ◽  
Guillaume Haiat
Keyword(s):  
Surface Roughness ◽  
Stress Shielding ◽  
Contact Ratio ◽  
Bone Implant ◽  
Bone Implant Contact

Advanced Glycation Endproducts and Rat Dental Implant Osseointegration

2010 ◽  
Vol 36 (2) ◽  
pp. 97-103 ◽  
Author(s):  
David G. Quintero ◽  
Julia N. Winger ◽  
Rania Khashaba ◽  
James L. Borke
Keyword(s):  
Bone Turnover ◽  
Bone Turnover Marker ◽  
Advanced Glycation Endproducts ◽  
Biomechanical Properties ◽  
Titanium Implants ◽  
Contact Ratio ◽  
Advanced Glycation ◽  
Bone Implant ◽  
Glycation Endproducts ◽  
Bone Implant Contact

Abstract Advanced glycation endproducts (AGEs) are a diverse group of molecular adducts formed in environments high in reducing sugars that accumulate with aging and in diabetes. This study tests the hypothesis that AGEs inhibit the stabile osseointegration of dental implants through tissue interactions that interfere with bone turnover and compromise the biomechanical properties at the bone-implant interface. Maxillary first molars were extracted from 32 rats and allowed to heal for 4 weeks. Titanium implants (1 mm × 3 mm) were placed in the healed sockets of 2 groups of 16 rats consisting of 8 rats injected 3 times/wk for 1 month with AGE (prepared from glucose and lysine) and 8 rats injected with vehicle as a control. AGE injections continued for an additional 14 or 28 days before sacrifice. X-ray images, blood, and tissues were collected to examine bone/implant contact ratio, serum pyridinoline ([PYD] a collagen breakdown marker), osteocalcin ([OSC] a bone formation marker), and for immunohistochemistry with antibodies to AGE and the bone turnover-marker protein matrix metalloproteinase1. Compared with the AGE-treated groups, the controls showed significantly higher bone/implant contact at both 14- and 28-day time points. PYD (P < .05) and OSC (trend) levels from controls showed decreases at 28 days when compared with AGE-treated groups. Immunohistochemistry with AGE-specific and bone turnover marker antibodies showed stronger staining associated with the implant/tissue interface in AGE-treated rats. Our studies indicate an association between AGE and inhibition of bone turnover, suggesting that the formation of AGE in high glycemic conditions, such as diabetes, may contribute to a slower rate of osseointegration that negatively affects implant stability.

scholarly journals Laser-treated stainless steel mini-screw implants: 3D surface roughness, bone-implant contact, and fracture resistance analysis

2015 ◽  
Vol 38 (2) ◽  
pp. 154-162 ◽  
Author(s):  
He-Kyong Kang ◽  
Tien-Min Chu ◽  
Paul Dechow ◽  
Kelton Stewart ◽  
Hee-Moon Kyung ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Fracture Resistance ◽  
Bone Implant ◽  
Resistance Analysis ◽  
3D Surface ◽  
3D Surface Roughness ◽  
Bone Implant Contact

In Vivo and In Vitro Evaluation of Coated HAp Films with Different Surface Morphology

2007 ◽  
Vol 539-543 ◽  
pp. 710-715
Author(s):  
Kotaro Kuroda ◽  
Ryoichi Ichino ◽  
Masazumi Okido
Keyword(s):  
Bone Formation ◽  
Surface Morphology ◽  
New Bone Formation ◽  
Contact Ratio ◽  
Bone Implant ◽  
Ft Ir ◽  
Mouse Osteoblast ◽  
Surface Morphologies

Hydroxyapatite (HAp) coatings were formed on cp titanium plates and rods by the thermal substrate method in an aqueous solution that included 0.3 mM Ca(H2PO4)2 and 0.7 mM CaCl2. The coating experiments were conducted at 40-140 oC and pH = 8 for 15 or 30 min. The properties for the coated samples were studied using XRD, EDX, FT-IR, and SEM. All the specimens were covered with HAp, which had different surface morphologies such as net-like, plate-like and needle-like. After cleaning and sterilization, all the coated specimens were subjected to in vivo and vitro testing. In the in vitro testing, the mouse osteoblast-like cells (MC3T3-E1) were cultured on the coated and non-coated specimens for up to 30 days. Moreover, the specimens (φ2 x 5 mm) were implanted in rats femoral for up to 8 weeks, the osseoinductivity on them were evaluated. In in vitro evaluations, there were not significant differences between the different surface morphologies. In in vivo evaluations, however, two weeks postimplantation, new bone formed on both the HAp coated and non-coated titanium rods in the cancellous and cortical bone. The bone-implant contact ratio, which was used for the evaluation of new bone formation, was significantly dependent on the surface morphology of the HAp, and the results demonstrated that the needle-like coating appears to promote rapid bone formation.

scholarly journals Finite Element Analysis of Tibial Bone-Implant Load Transfer and Bone Strains with a Modern Fixed-bearing Total Ankle Replacement

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0011
Author(s):  
Daniel Sturnick ◽  
Guilherme Saito ◽  
Jonathan Deland ◽  
Constantine Demetracopoulos ◽  
Xiang Chen ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Tibial Component ◽  
Load Transfer ◽  
Young's Modulus ◽  
Stress Shielding ◽  
Poisson's Ratio ◽  
Bone Implant ◽  
Tibial Tray ◽  
Tibial Bone

Category: Ankle Arthritis Introduction/Purpose: Loosening of the tibial component is the primary failure mode in total ankle arthroplasty (TAA). The mechanics of the tibial component loosening has not been fully elucidated. Clinically observed radiolucency and cyst formation in the periprosthetic bone may be associated with unfavorable load sharing at and adjacent to the tibial bone-implant interface contributory to implant loosening. However, no study has fully investigated the load transfer from the tibial component to the bone under multiaxial loads in the ankle. The objective of this study was to utilize subject-specific finite element (FE) models to investigate the load transfer through tibial bone-implant interface, as well as periprosthetic bone strains under simulated multiaxial loads. Methods: Bone-implant FE models were developed from CT datasets of three cadaveric specimens that underwent TAA using a modern fixed-bearing tibial implant (a cobalt-chrome tray with a polyethylene bearing, Salto Talaris, Integra LifeSciences). Implant placement was estimated from the post-operative CT scans. Bone was modeled as isotropic elastic material with inhomogeneous Young’s modulus (determined from CT Hounsfield units) and a uniform Poisson’s ratio of 0.3. The tibial tray (Young’s modulus: 200,000 MPa, Poisson’s ratio: 0.3) and the polyethylene bearing (Young’s modulus: 600 MPa, Poisson’s ratio: 0.4) were modeled as isotropic elastic. A 100-N compressive force, a 300-N anterior force, and a 3-Nm moment were applied to two literature based loading regions on the surface of the polyethylene bearing. The proximal tibia was fixed in all directions. The bone-implant contact was modeled as frictional with a coefficient of 0.7, whereas the polyethylene bearing was bonded to the tray. Results: Along the long axis of the tibia, load was transferred to the bone primarily through the flat bone-contacting base of the tibial tray and the cylindrical top of the keel, little amount of load was transferred to the bone between those two features (Fig. 1A). Low strain was observed in bone regions medial and lateral to the keel of the tibial tray, where bone cysts were often observed clinically (Fig. 1A). On average, approximated 70% of load was transferred through the anterior aspect of the tibial tray at the flat bone-contacting base, which corresponded to the relatively high bone strain adjacent to the implant edge in the anterior bone-implant interface (Fig. 1B). Conclusion: Our results demonstrated a two-step load transfer pattern along the long axis of the tibia, revealing regions with low bone strain peripheral to the keel indicative to stress shielding. Those regions were consistent with the locations of bone cysts observed clinically, which may be explained by the stress shielding associated remodeling of bone. These findings could also describe the mechanism of implant loosening and failure. Future studies may use our model to simulate more loading scenarios, as well as different implant placement and design, to identify means to optimize load transfer to the bone and prevent stress shielding.

scholarly journals Prediction of stress shielding around implant screws induced by three-point and four-point bending

2019 ◽  
Vol 15 (4) ◽  
pp. 548-554
Author(s):  
Izzawati Basirom ◽  
Mohd Afendi Rojan ◽  
Mohd Shukry Abdul Majid ◽  
Nor Alia Md Zain ◽  
Mohd Yazid Bajuri
Keyword(s):  
Strain Energy ◽  
Stress Shielding ◽  
Lateral Impact ◽  
Bone Implant ◽  
Femur Bone ◽  
Four Point Bending ◽  
Biomechanical Compatibility ◽  
Bending Load ◽  
Fracture Area ◽  
Bending Behavior

Implant screws failure commonly occurs due to the load that constantly generated by the patient’s body to the fracture area. Bending load is often encountered in femur bone due to lateral impact which affected the bone and also the implants installed. Consequently, the load will lead to the failure of implants that can cause loosening or tightening of implants. Henceforth, in this manner, it is significant to study the bending behavior of bone implant in femur bone. The aim of this study was to analyze the stress shielding of bone implant on the internal fixator. 3D technique is able to show the overall deformation and stress distribution. The lower the biomechanical compatibility, the lower the STP value obtained. In addition, the variation of elastic modulus (E) of the screws materials, 200GPa (Stainless Steel) and 113.8GPa (Titanium) resulted in the increase of the total stress transferred (STP) between screw and bone interface. In this work, strain energy density (SED) was determined as a good indicator of stress shielding.

Histologic and Radiographic Evaluation of Progressive Loading on Implants Placed into Extraction Sockets

2007 ◽  
Vol 330-332 ◽  
pp. 1413-1416 ◽  
Author(s):  
Yu Ban ◽  
Ping Gong ◽  
Shao An Wang ◽  
N. Geng ◽  
X.G. Liu ◽  
...  
Keyword(s):  
Bone Loss ◽  
Radiographic Evaluation ◽  
Contact Ratio ◽  
Control Groups ◽  
Bone Implant ◽  
Paired Student ◽  
Loading System ◽  
Bone To Implant Contact ◽  
The Mean ◽  
Progressive Loading

To evaluate the effects of progressive loading on implants placed into extraction sockets. 4 beagle dogs were extracted bilateral 3rd, 4th and 2nd premolar and immediately inserted the implant at first surgery (0d), 14d and 21d. Using the newly developed vertical occlusion loading system, progressive loading procedures were taken 24h after insertion. The vertical bone loss (VBL) and bone-to-implant contact ratio (BIC) was measured by image analysis software and analyzed using the paired student t test. After 28d period of healing, each animal was sacrificed and the samples were evaluated by scanning electron microscopy (SEM). The mean vertical bone loss in control groups was larger than that of the experimental groups at 14, 21 and 28 day (P<0.05). SEM showed that the mineralization rate of experimental groups was faster than the control groups. The bone-implant contact ratios in experimental groups were more than that in the control groups. The differences were statistically significant (P<0.05). Compared with non-loading implant, progressive loading can promote osseointegration and decrease vertical bone loss. Progressive loading of implants placed into extraction sockets can be performed without interfering with the osseointegration process.

Strontium-Loaded Nanotubes of Ti–24Nb–4Zr–8Sn Alloys for Biomedical Implantation

2021 ◽  
Vol 17 (9) ◽  
pp. 1812-1823
Author(s):  
Fei Liu ◽  
Xinyu Wang ◽  
Shujun Li ◽  
Yiheng Liao ◽  
Xinxin Zhan ◽  
...  
Keyword(s):  
Early Stage ◽  
Contact Rate ◽  
Hard Tissue ◽  
Tissue Slices ◽  
Bone Implant ◽  
P Elements ◽  
Low Elastic Modulus ◽  
Bone Implant Contact

Ti–24Nb–4Zr–8Sn (Ti2448) alloys, with a relatively low elastic modulus and unique mechanical properties, are desirable materials for oral implantation. In the current study, a multifaceted strontium-incorporating nanotube coating was fabricated on a Ti2448 alloy (Ti2-NTSr) through anodization and hydrothermal procedures. In vitro, the Ti2-NTSr specimens demonstrated better osteogenic properties and more favorable osteoimmunomodulatory abilities. Moreover, macrophages on Ti2-NTSr specimens could improve the recruitment and osteogenic differentiation of osteoblasts. In vivo, dense clots with highly branched, thin fibrins and small pores existed on the Ti2-NTSr implant in the early stage after surgery. Analysis of the deposition of Ca and P elements, hard tissue slices and the bone-implant contact rate (BIC%) of the Ti2-NTSr implants also showed superior osseointegration. Taken together, these results demonstrate that the Ti2-NTSr coating may maximize the clinical outcomes of Ti2448 alloys for implantation applications.

scholarly journals Development of elastically graded titanium alloys for biomedical applications

2020 ◽  
Vol 321 ◽  
pp. 05016
Author(s):  
Stéphanie DELANNOY ◽  
Sarah BAÏZ ◽  
Pascal LAHEURTE ◽  
Laurence JORDAN ◽  
Frédéric PRIMA
Keyword(s):  
Titanium Alloys ◽  
Biomedical Applications ◽  
Surface Deformation ◽  
Stress Shielding ◽  
Bone Implant ◽  
Strategy Process ◽  
Elastic Mismatch ◽  
Graded Properties ◽  
Selection Of ◽  
Zr Alloys

Recent works have shown that the elastic mismatch observed at the bone / implant interface could be responsible for stress shielding issues causing bone resorption phenomena and potentially implant failures. In the present study, new advanced thermomechanical approaches leading to titanium alloys with graded elastic properties are proposed. The underlying philosophy and the whole methodology is detailed here, from the selection of candidates with large elastic variability to the creation of gradients, involving the identification of microstructure-properties relationships and the use of appropriate thermo-mechanical treatments. Applied on Ti-Nb-Zr alloys, these original routes enabled to get the following graded properties: elastic modulus from 85 to 65GPa over 400μm for TNZ alloy by surface deformation, and from 130 to 75GPa over 100μm for Ti-13-13 by preferential dissolution. These promising results thus validated the previously designed material-strategy-process combinations.

Periprosthetic bone response to axial loading following TKR

2019 ◽  
Vol 16 (2) ◽  
pp. 359-372
Author(s):  
Ravishanker Baliga ◽  
Sharat K. Rao ◽  
Raghuvir Pai ◽  
Satish B. Shenoy ◽  
Atmananda K. Hegde ◽  
...  
Keyword(s):  
Stress Shielding ◽  
Axial Loading ◽  
Computational Time ◽  
System Response ◽  
Polyethylene Insert ◽  
Bone Implant ◽  
Content Type ◽  
Implant Material ◽  
Bone Response ◽  
Implant System

Purpose The purpose of this paper is to investigate by means of finite element analysis (FEA), the effect of polyethylene insert thickness and implant material, under axial loading following TKA. Design/methodology/approach The 3D geometric model of bone was processed using the CT scan data by MIMICS (3matic Inc.), package. Implant components were 3D scanned and subsequently 3D modeled using ANSYS Spaceclaim and meshed in Hypermesh (Altair Hyperworks). The assembled, meshed bone-implant model was then input to ABAQUS for FE simulations, considering axial loading. Findings Polyethylene insert thickness was found to have very little or no significance (p>0.05) on the mechanical performance, namely, stress, strain and stress shielding of bone-implant system. Implant material was found to have a very significant effect (p<0.05) on the performance parameters and greatly reduced the high stress zones up to 60 percent on the tibial flange region and periprosthetic region of tibia. Originality/value Very few FEA studies have been done considering a full bone with heterogeneous material properties, to save computational time. Moreover, four different polyethylene insert thickness with a metal-backed and all-poly tibial tray was considered as the variables affecting the bone-implant system response, under static axial loading. The authors believe that considering a full bone shall lead to more precise outcomes, in terms of the response of bone-implant system, namely, stress, strains and stress shielding in the periprosthetic region, to loading.

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