scholarly journals Sustainable Surface Modification of Polyetheretherketone (PEEK) Implants by Hydroxyapatite/Silica Coating—An In Vivo Animal Study

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4589
Author(s):  
Thomas Frankenberger ◽  
Constantin Leon Graw ◽  
Nadja Engel ◽  
Thomas Gerber ◽  
Bernhard Frerich ◽  
...  

Polyetheretherketone (PEEK) has the potential to overcome some of the disadvantages of titanium interbody implants in anterior cervical and discectomy and fusion (ACDF). However, PEEK shows an inferior biological behavior regarding osseointegration and bioactivity. Therefore, the aim of the study was to create a bioactive surface coating on PEEK implants with a unique nanopore structure enabling the generation of a long-lasting interfacial composite layer between coating material and implant. Seventy-two PEEK implants—each thirty-six pure PEEK implants (PI) and thirty-six PEEK implants with a sprayed coating consisting of nanocrystalline hydroxyapatite (ncHA) embedded in a silica matrix and interfacial composite layer (SPI)—were inserted in the femoral condyles of adult rats using a split-side model. After 2, 4 and 8 weeks, the femur bones were harvested. Half of the femur bones were used in histological and histomorphometrical analyses. Additionally, pull-out tests were performed in the second half. Postoperative healing was uneventful for all animals, and no postoperative complications were observed. Considerable crestal and medullary bone remodeling could be found around all implants, with faster bone formation around the SPI and fewer regions with fibrous tissue barriers between implant and bone. Histomorphometrical analyses showed a higher bone to implant contact (BIC) in SPI after 4 and 8 weeks (p < 0.05). Pull-out tests revealed higher pull-out forces in SPI at all time points (p < 0.01). The presented findings demonstrate that a combination of a bioactive coating and the permanent chemical and structural modified interfacial composite layer can improve bone formation at the implant surface by creating a sustainable bone-implant interface. This might be a promising way to overcome the bioinert surface property of PEEK-based implants.

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1670 ◽  
Author(s):  
Wölfle-Roos JV ◽  
Katmer Amet B ◽  
Fiedler J ◽  
Michels H ◽  
Kappelt G ◽  
...  

Background: Uncemented implants are still associated with several major challenges, especially with regard to their manufacturing and their osseointegration. In this study, a novel manufacturing technique—an optimized form of precision casting—and a novel surface modification to promote osseointegration—calcium and phosphorus ion implantation into the implant surface—were tested in vivo. Methods: Cylindrical Ti6Al4V implants were inserted bilaterally into the tibia of 110 rats. We compared two generations of cast Ti6Al4V implants (CAST 1st GEN, n = 22, and CAST 2nd GEN, n = 22) as well as cast 2nd GEN Ti6Al4V implants with calcium (CAST + CA, n = 22) and phosphorus (CAST + P, n = 22) ion implantation to standard machined Ti6Al4V implants (control, n = 22). After 4 and 12 weeks, maximal pull-out force and bone-to-implant contact rate (BIC) were measured and compared between all five groups. Results: There was no significant difference between all five groups after 4 weeks or 12 weeks with regard to pull-out force (p > 0.05, Kruskal Wallis test). Histomorphometric analysis showed no significant difference of BIC after 4 weeks (p > 0.05, Kruskal–Wallis test), whereas there was a trend towards a higher BIC in the CAST + P group (54.8% ± 15.2%), especially compared to the control group (38.6% ± 12.8%) after 12 weeks (p = 0.053, Kruskal–Wallis test). Conclusion: In this study, we found no indication of inferiority of Ti6Al4V implants cast with the optimized centrifugal precision casting technique of the second generation compared to standard Ti6Al4V implants. As the employed manufacturing process holds considerable economic potential, mainly due to a significantly decreased material demand per implant by casting near net-shape instead of milling away most of the starting ingot, its application in manufacturing uncemented implants seems promising. However, no significant advantages of calcium or phosphorus ion implantation could be observed in this study. Due to the promising results of ion implantation in previous in vitro and in vivo studies, further in vivo studies with different ion implantation conditions should be considered.


2011 ◽  
Vol 493-494 ◽  
pp. 539-544
Author(s):  
Guler Ungan ◽  
F. Ak Azem ◽  
Ahmet Cakir

Ti6Al4V alloy commonly used in human body for load bearing prosthesis was coated by micro arc oxidation (MAO) with magnesium rich TiO2 oxide. Since the presence of magnesium in bone tissues is known to promote bone formation and proliferation in physiological environment, its integration with TiO2 on implant surface could bring about a bioactivity for a fast bone formation and proliferation. The formation of a composite layer consisting of Mg integrated TiO2 by MAO process was carried out in an electrolyte with different magnesium content. The characterization studies of these coatings were performed by using X-ray diffractometry (XRD), scanning electron microscopy (SEM) coupled with EDS analysis and XP2 surface profilometry.


Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1035
Author(s):  
Mohammed E. Sayed ◽  
Maryam H. Mugri ◽  
Mazen A. Almasri ◽  
Manea Musa Al-Ahmari ◽  
Shilpa Bhandi ◽  
...  

Dental implants are a widely used treatment modality for oral rehabilitation. Implant failures can be a result of many factors, with poor osseointegration being the main culprit. The present systematic review aimed to assess the effect of stem cells on the osseointegration of dental implants. An electronic search of the MEDLINE, LILACS, and EMBASE databases was conducted. We examined quantitative preclinical studies that reported on the effect of mesenchymal stem cells on bone healing after implant insertion. Eighteen studies that fulfilled the inclusion criteria were included. Various surface modification strategies, sites of placement, and cell origins were analyzed. The majority of the selected studies showed a high risk of bias, indicating that caution must be exercised in their interpretation. All the included studies reported that the stem cells used with graft material and scaffolds promoted osseointegration with higher levels of new bone formation. The mesenchymal cells attached to the implant surface facilitated the expression of bio-functionalized biomaterial surfaces, to boost bone formation and osseointegration at the bone–implant interfaces. There was a promotion of osteogenic differentiation of human mesenchymal cells and osseointegration of biomaterial implants, both in vitro and in vivo. These results highlight the significance of biomodified implant surfaces that can enhance osseointegration. These innovations can improve the stability and success rate of the implants used for oral rehabilitation.


1992 ◽  
Vol 133 (2) ◽  
pp. 189-195 ◽  
Author(s):  
J. W. M. Chow ◽  
J. M. Lean ◽  
T. Abe ◽  
T. J. Chambers

ABSTRACT We have previously demonstrated that administration of oestrogen, at doses sufficient to raise serum concentrations to those seen in late pregnancy, increases trabecular bone formation in the metaphysis of adult rats. To determine whether prostaglandins (PGs), which have been shown to induce osteogenesis in vivo, play a role in the induction of bone formation by oestrogen, 13-week-old female rats were given daily doses of 4 mg 17β-oestradiol (OE2)/kg for 17 days, alone or with indomethacin (1 mg/kg). The rats were also given double fluorochrome labels and at the end of the experiment tibias were subjected to histomorphometric assessment. Treatment with OE2 suppressed longitudinal bone growth and increased uterine wet weight, as expected, and neither response was affected by indomethacin. Oestrogen also induced a threefold increase in trabecular bone formation in the proximal tibial metaphysis, which resulted in a substantial increase in trabecular bone volume. As previously observed, the increase in bone formation was predominantly due to an increase in osteoblast recruitment (as judged by an increase in the percentage of bone surface showing double fluorochrome labels), with only a minor increase in the activity of mature osteoblasts (as judged by the mineral apposition rate). Indomethacin abolished the increase in osteoblastic recruitment, but the activity of mature osteoblastic cells remained high. The bone formation rate and bone volume remained similar to controls. The results suggest that PG production may be necessary for the increased osteoblastic recruitment induced by oestrogen, but not to mediate the effects of oestrogen on the activity of mature osteoblasts. Journal of Endocrinology (1992) 133, 189–195


1999 ◽  
Vol 13 (1) ◽  
pp. 99-119 ◽  
Author(s):  
John B. Brunski

Since dental implants must withstand relatively large forces and moments in function, a better understanding of in vivo bone response to loading would aid implant design. The following topics are essential in this problem. (1) Theoretical models and experimental data are available for understanding implant loading as an aid to case planning. (2) At least for several months after surgery, bone healing in gaps between implant and bone as well as in pre-existing damaged bone will determine interface structure and properties. The ongoing healing creates a complicated environment. (3) Recent studies reveal that an interfacial cement line exists between the implant surface and bone for titanium and hydroxyapatite (HA). Since cement lines in normal bone have been identified as weak interfaces, a cement line at a bone-biomaterial interface may also be a weak point. Indeed, data on interfacial shear and tensile "bond" strengths are consistent with this idea. (4) Excessive interfacial micromotion early after implantation interferes with local bone healing and predisposes to a fibrous tissue interface instead of osseointegration. (5) Large strains can damage bone. For implants that have healed in situ for several months before being loaded, data support the hypothesis that interfacial overload occurs if the strains are excessive in interfacial bone. While bone "adaptation" to loading is a long-standing concept in bone physiology, researchers may sometimes be too willing to accept this paradigm as an exclusive explanation of in vivo tissue responses during experiments, while overlooking confounding variables, alternative (non-mechanical) explanations, and the possibility that different types of bone ( e.g., woven bone, Haversian bone, plexiform bone) may have different sensitivities to loading under healing vs. quiescent conditions.


2013 ◽  
Vol 7 (1) ◽  
pp. 18-24 ◽  
Author(s):  
Jeppe Barckman ◽  
Jorgen Baas ◽  
Mette Sørensen ◽  
Joan E Bechtold ◽  
Kjeld Soballe

Purpose: Periosteum provides essential cellular and biological components necessary for fracture healing and bone repair. We hypothesized that augmenting allograft bone by adding fragmented autologous periosteum would improve fixation of grafted implants. Methods: In each of twelve dogs, we implanted two unloaded cylindrical (10 mm x 6 mm) titanium implants into the distal femur. The implants were surrounded by a 2.5-mm gap into which morselized allograft bone with or without addition of fragmented autologous periosteum was impacted. After four weeks, the animals were euthanized and the implants were evaluated by histomorphometric analysis and mechanical push-out test. Results: Although less new bone was found on the implant surface and increased volume of fibrous tissue was present in the gap around the implant, no difference was found between treatment groups regarding the mechanical parameters. Increased new bone formation was observed in the immediate vicinity of the periosteum fragments within the bone graft. Conclusion: The method for periosteal augmentation used in this study did not alter the mechanical fixation although osseointegration was impaired. The observed activity of new bone formation at the boundary of the periosteum fragments may indicate maintained bone stimulating properties of the transplanted cambium layer. Augmenting the bone graft by smaller fragments of periosteum, isolated cambium layer tissue or cultured periosteal cells could be studied in the future.


2019 ◽  
Vol 8 (5) ◽  
pp. 604 ◽  
Author(s):  
Jung-Yoo Choi ◽  
Tomas Albrektsson ◽  
Young-Jun Jeon ◽  
In-Sung Luke Yeo

It is challenging to remove dental implants once they have been inserted into the bone because it is hard to visualize the actual process of bone formation after implant installation, not to mention the cellular events that occur therein. During bone formation, contact osteogenesis occurs on roughened implant surfaces, while distance osteogenesis occurs on smooth implant surfaces. In the literature, there have been many in vitro model studies of bone formation on simulated dental implants using flattened titanium (Ti) discs; however, the purpose of this study was to identify the in vivo cell responses to the implant surfaces on actual, three-dimensional (3D) dental Ti implants and the surrounding bone in contact with such implants at the electron microscopic level using two different types of implant surfaces. In particular, the different parts of the implant structures were scrutinized. In this study, dental implants were installed in rabbit tibiae. The implants and bone were removed on day 10 and, subsequently, assessed using scanning electron microscopy (SEM), immunofluorescence microscopy (IF), transmission electron microscopy (TEM), focused ion-beam (FIB) system with Cs-corrected TEM (Cs-STEM), and confocal laser scanning microscopy (CLSM)—which were used to determine the implant surface characteristics and to identify the cells according to the different structural parts of the turned and roughened implants. The cell attachment pattern was revealed according to the different structural components of each implant surface and bone. Different cell responses to the implant surfaces and the surrounding bone were attained at an electron microscopic level in an in vivo model. These results shed light on cell behavioral patterns that occur during bone regeneration and could be a guide in the use of electron microscopy for 3D dental implants in an in vivo model.


2014 ◽  
Vol 30 (2) ◽  
pp. 200-214 ◽  
Author(s):  
M.S. Walter ◽  
M.J. Frank ◽  
M. Satué ◽  
M. Monjo ◽  
H.J. Rønold ◽  
...  

2004 ◽  
Vol 449-452 ◽  
pp. 1221-1224
Author(s):  
Baek Hee Lee ◽  
Young Do Kim ◽  
Kyu Hwan Lee

Geometrical and chemical designs of an implant surface affected the stabilization of implant and the healing of tissue. In this study, effects of surface designs in implants on in vivo behavior and mechanical stability were compared by histological and mechanical analyses. The implants were transversely grafted on dog thighbone and healed for 4 and 8 weeks. The pull-out strength between living bone and implant was evaluated by universal testing machine (UTM).


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