scholarly journals In VivoMicroCT Monitoring of Osteomyelitis in a Rat Model

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Vincent A. Stadelmann ◽  
Inga Potapova ◽  
Karin Camenisch ◽  
Dirk Nehrbass ◽  
R. Geoff Richards ◽  
...  

Infection associated with orthopedic implants often results in bone loss and requires surgical removal of the implant. The aim of this study was to evaluate morphological changes of bone adjacent to a bacteria-colonized implant, with the aim of identifying temporal patterns that are characteristic of infection. In anin vivostudy with rats, bone changes were assessed usingin vivomicroCT at 7 time points during a one-month postoperative period. The rats received either a sterile orStaphylococcus aureus-colonized polyetheretherketone screw in the tibia. Bone-implant contact, bone fraction, and bone changes (quiescent, resorbed, and new bone) were calculated from consecutive scans and validated against histomorphometry. The screw pullout strength was estimated from FE models and the results were validated against mechanical testing. In the sterile group, bone-implant contact, bone fraction, and mechanical fixation increased steadily until day 14 and then plateaued. In the infected group, they decreased rapidly. Bone formation was reduced while resorption was increased, with maximum effects observed within 6 days. In summary, the model presented is capable of evaluating the patterns of bone changes due to implant-related infections. The combined use of longitudinalin vivomicroCT imaging and image-based finite element analysis provides characteristic signs of infection within 6 days.

2021 ◽  
Vol 17 (9) ◽  
pp. 1812-1823
Author(s):  
Fei Liu ◽  
Xinyu Wang ◽  
Shujun Li ◽  
Yiheng Liao ◽  
Xinxin Zhan ◽  
...  

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.


2011 ◽  
Vol 34 (4) ◽  
pp. 202 ◽  
Author(s):  
Davide Berardi ◽  
Simona De Benedittis ◽  
Andrea Scoccia ◽  
Giorgio Perfetti ◽  
Pio Conti

Purpose: The purpose of this study was to confirm the validity of laser treated implant surfaces, with regard to high superficial purity preservation and to extremely regular and uniform roughness surfaces. Methods: In this in vivo study, seven different laser treated implant surfaces were analyzed. A diode-pumped solid state source laser, in a Q-Switch output mode, was used at various wavelengths, which were chosen to generate surface irregularities of varying diameter, depth and pitch. Twenty one implants were placed in 11 New Zealand rabbits. Eight weeks after surgery, implants were harvested for histometric analysis: total, threads and body bone-to-implant, and bone-to-implant contacts were measured. The morphologic analysis of the surface was carried out using a Scanning Electron Microscope. Results: Average bone-implant contact values were approximately 50% for all tested surfaces. Both total and threads values, within the same processing pattern group, had a high variance. Bone-implant contact thread and body variances were different, so that is possible that laser beam angle is able to modify the superficial roughness and thus the histological response. Conclusions: Implants provided with pores of 20 and 25 µm achieved more than satisfactory bone-implant contact partial peaks. Further statistically significant experiments are needed in order to study, in depth, these surfaces.


2019 ◽  
Vol 16 (154) ◽  
pp. 20190108 ◽  
Author(s):  
Jingxiao Zhong ◽  
Junning Chen ◽  
Richard Weinkamer ◽  
M. Ali Darendeliler ◽  
Michael V. Swain ◽  
...  

Orthodontic root resorption is a common side effect of orthodontic therapy. It has been shown that high hydrostatic pressure in the periodontal ligament (PDL) generated by orthodontic forces will trigger recruitment of odontoclasts, leaving resorption craters on root surfaces. The patterns of resorption craters are the traces of odontoclast activity. This study aimed to investigate resorptive patterns by: (i) quantifying spatial root resorption under two different levels of in vivo orthodontic loadings using microCT imaging techniques and (ii) correlating the spatial distribution pattern of resorption craters with the induced mechanobiological stimulus field in PDL through nonlinear finite-element analysis (FEA) in silico . Results indicated that the heavy force led to a larger total resorption volume than the light force, mainly by presenting greater individual crater volumes ( p < 0.001) than increasing crater numbers, suggesting that increased mechano-stimulus predominantly boosted cellular resorption activity rather than recruiting more odontoclasts. Furthermore, buccal–cervical and lingual–apical regions in both groups were found to have significantly larger resorption volumes than other regions ( p < 0.005). These clinical observations are complemented by the FEA results, suggesting that root resorption was more likely to occur when the volume average compressive hydrostatic pressure exceeded the capillary blood pressure (4.7 kPa).


Author(s):  
Margherita Tumedei ◽  
Adriano Piattelli ◽  
Marco Degidi ◽  
Carlo Mangano ◽  
Giovanna Iezzi

Background: The aim of the present review was to assess the histological and histomorphometrical data from the paper published by our Laboratory on peri-implant bone in dental implants in different loading conditions. Methods: The papers published in different implant loading conditions, in dental implants retrieved from humans, and in the Hard Tissues Research Center of the University of Chieti-Pescara, Italy, were screened on MEDLINE/PubMed, Embase, Scopus, and other electronic databases until 31 December 2018. Only articles that reported the histological and histomorphometrical values of the Bone-Implant Contact (BIC) were selected. Results: The system selection provided a total of 155 papers. The manuscripts included for the narrative review were 57. These papers provided histological and histomorphometrical data. Conclusions: The bone remodeling around dental implants was found to be a dynamic process; loading changed the microstructure of the peri-implant bone; and implants were found to provide a successful function, over several decades, with different range of degrees of BIC in vivo (varying from a little more than 30% to a little more than 90%). Loaded implants presented a 10%–12% higher BIC values when compared to submerged, unloaded implants, and rougher surfaces had, on average, about a 10% higher BIC than machined surfaces.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Vincent A. Stadelmann ◽  
Keith Thompson ◽  
Stephan Zeiter ◽  
Karin Camenisch ◽  
Ursula Styger ◽  
...  

AbstractSubclinical infection associated with orthopedic devices can be challenging to diagnose. The goal of this study was to evaluate longitudinal, microcomputed tomography (microCT) imaging in a rat model of subclinical orthopedic device-related infection caused by Staphylococcus epidermidis and four different Cutibacterium (previously Propionibacterium) acnes strains, and compare outcomes with non-inoculated and historical S. aureus-inoculated controls. Sterile screws or screws colonized with bacteria were placed in the tibia of 38 adult Wistar rats [n = 6 sterile screws; n = 6 S. epidermidis-colonized screws; n = 26 C. acnes-colonized screws (covering all three main subspecies)]. Regular microCT scans were taken over 28 days and processed for quantitative time-lapse imaging with dynamic histomorphometry. At euthanasia, tissues were processed for semiquantitative histopathology or quantitative bacteriology. All rats receiving sterile screws were culture-negative at euthanasia and displayed progressive bony encapsulation of the screw. All rats inoculated with S. epidermidis-colonized screws were culture-positive and displayed minor changes in peri-implant bone, characteristic of subclinical infection. Five of the 17 rats in the C. acnes inoculated group were culture positive at euthanasia and displayed bone changes at the interface of the screw and bone, but not deeper in the peri-implant bone. Dynamic histomorphometry revealed significant differences in osseointegration, bone remodeling and periosteal reactions between groups that were not measurable by visual observation of still microCT images. Our study illustrates the added value of merging 3D microCT data from subsequent timepoints and producing inherently richer 4D data for the detection and characterization of subclinical orthopedic infections, whilst also reducing animal use.


2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Mengfei Yu ◽  
Yu Liu ◽  
Xiaowen Yu ◽  
Jianhua Li ◽  
Wenquan Zhao ◽  
...  

Abstract Natural extracellular matrices (ECMs) are three-dimensional (3D) and multi-scale hierarchical structure. However, coatings used as ECM-mimicking structures for osteogenesis are typically two-dimensional or single-scaled. Here, we design a distinct quasi-three-dimensional hierarchical topography integrated of density-controlled titania nanodots and nanorods. We find cellular pseudopods preferred to anchor deeply across the distinct 3D topography, dependently of the relative density of nanorods, which promote the osteogenic differentiation of osteoblast but not the viability of fibroblast. The in vivo experimental results further indicate that the new bone formation, the relative bone-implant contact as well as the push-put strength, are significantly enhanced on the 3D hierarchical topography. We also show that the exposures of HFN7.1 and mAb1937 critical functional motifs of fibronectin for cellular anchorage are up-regulated on the 3D hierarchical topography, which might synergistically promote the osteogenesis. Our findings suggest the multi-dimensions and multi-scales as vital characteristic of cell-ECM interactions and as an important design parameter for bone implant coatings.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Antonio Scarano ◽  
Adriano Piattelli ◽  
Alesandro Quaranta ◽  
Felice Lorusso

Background. Scientific evidence in the field of implant dentistry of the past 20 years established that titanium rough surfaces have shown improved osseointegration rates. In a majority of dental implants, the surface microroughness was obtained by grit blasting and/or acid etching. The aim of the study was to evaluate in vivo two different highly hydrophilic surfaces at different experimental times. Methods. Calcium-modified (CA) and SLActive surfaces were evaluated and a total of 18 implants for each type of surface were positioned into the rabbit articular femoral knee-joint in a split model experiment, and they were evaluated histologically and histomorphometrically at 15, 30, and 60 days of healing. Results. Bone-implant contact (BIC) at the two-implant surfaces was significantly different in favor of the CA surface at 15 days (p=0.027), while SLActive displayed not significantly higher values at 30 (p=0.51) and 60 days (p=0.061). Conclusion. Both implant surfaces show an intimate interaction with newly formed bone.


Author(s):  
Shenghui Lan ◽  
Abhishek Chandra ◽  
Ling Qin ◽  
X. Sherry Liu

Micro computed tomography (μCT) has been widely used to study 3-dimensional (3D) microstructure of bone specimens. In the recent decade, in vivo μCT scanners have become available to monitor longitudinal bone changes in rodents (1,2). The current in vivo μCT scan can obtain images with an isotropic voxel size up to 10.5 μm, which is high enough for direct 3D bone microstructural analyses. Moreover, based on these high-resolution images, micro finite element (μFE) models can be generated to estimate mechanical properties of bone. Therefore, by using in vivo μCT imaging and μFE analysis techniques, changes in geometry, microstructure, and mechanical properties of rodent bone, in response to either diseases or treatments, can be visualized and quantified over time.


2005 ◽  
Vol 16 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Cristina Costa de Almeida ◽  
Lídia Ágata Sena ◽  
Marcelo Pinto ◽  
Carlos Alberto Muller ◽  
José Henrique Cavalcanti Lima ◽  
...  

This study compared in vivo the performances of commercially pure titanium (cp Ti) screw dental implants either uncoated or coated with synthetic hydroxyapatite (HA) by electrophoresis. The HA coating was characterized by scanning electron microscopy, energy dispersive spectroscopy (EDS) and Fourier-transform infrared (FT-IR) spectroscopy. Well-adhered carbonated-hydroxyapatite layers (4- to-8-µm-thick) were obtained. In vivo tests were carried out by insertion of both uncoated and HA-coated implants into rabbit tibiae for 8 or 12 weeks. Histomorphometric analysis was performed by scanning electron microscopy with the aid of image-processing software. Results showed significantly greater bone-implant contact for HA-coated implants (p<0.05) than cp Ti implants. Comparison of bone content inside the screw implants showed no significant differences (p>0.05) between both types of implants, although cp Ti had numerically higher percentage of bone content than HA-coated implants. In conclusion, the HA-coated implants had better performance regarding the bone-implant contact area than the uncoated implants; coating by electrophoresis proved to be a valuable process to coat metallic implants with an osteoconductive material such as hydroxyapatite.


Sign in / Sign up

Export Citation Format

Share Document