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Biomaterials Advances Apr 2023Many studies have found that the threshold of occlusal force tolerated by titanium-based implants is significantly lower than that of natural teeth due to differences in... (Review)
Review
Many studies have found that the threshold of occlusal force tolerated by titanium-based implants is significantly lower than that of natural teeth due to differences in biomechanical mechanisms. Therefore, implants are considered to be susceptible to occlusal trauma. In clinical practice, many implants have shown satisfactory biocompatibility, but the balance between biomechanics and biofunction remains a huge clinical challenge. This paper comprehensively analyzes and summarizes various stress distribution optimization methods to explore strategies for improving the resistance of the implants to adverse stress. Improving stress resistance reduces occlusal trauma and shortens the gap between implants and natural teeth in occlusal function. The study found that: 1) specific implant-abutment connection design can change the force transfer efficiency and force conduction direction of the load at the BII; 2) reasonable implant surface structure and morphological character design can promote osseointegration, maintain alveolar bone height, and reduce the maximum effective stress at the BII; and 3) the elastic modulus of implants matched to surrounding bone tissue can reduce the stress shielding, resulting in a more uniform stress distribution at the BII. This study concluded that the core BII stress distribution optimization lies in increasing the stress distribution area and reducing the local stress peak value at the BII. This improves the biomechanical adaptability of the implants, increasing their long-term survival rate.
Topics: Humans; Bone-Implant Interface; Dental Occlusion, Traumatic; Stress, Mechanical; Osseointegration; Bone and Bones
PubMed: 36841109
DOI: 10.1016/j.bioadv.2023.213342 -
Journal of Applied Biomaterials &... 2021Here, we present a bone implant system of phase-oriented titanium dioxide (TiO) fabricated by the micro-arc oxidation method (MAO) on β-Ti to facilitate improved...
Here, we present a bone implant system of phase-oriented titanium dioxide (TiO) fabricated by the micro-arc oxidation method (MAO) on β-Ti to facilitate improved osseointegration. This (101) rutile-phase-dominant MAO TiO (R-TiO) is biocompatible due to its high surface roughness, bone-mimetic structure, and preferential crystalline orientation. Furthermore, (101) R-TiO possesses active and abundant hydroxyl groups that play a significant role in enhancing hydroxyapatite formation and cell adhesion and promote cell activity leading to osseointegration. The implants had been elicited their favorable cellular behavior in vitro in the previous publications; in addition, they exhibit excellent shear strength and promote bone-implant contact, osteogenesis, and tissue formation in vivo. Hence, it can be concluded that this MAO R-TiO bone implant system provides a favorable active surface for efficient osseointegration and is suitable for clinical applications.
Topics: Coated Materials, Biocompatible; Osseointegration; Surface Properties; Titanium
PubMed: 33909530
DOI: 10.1177/22808000211006878 -
Medicina (Kaunas, Lithuania) Jun 2022Background and Objectives: The gold standard for a successful prosthetic approach is the osseointegration of an implant. However, this integration can be a problem in...
Background and Objectives: The gold standard for a successful prosthetic approach is the osseointegration of an implant. However, this integration can be a problem in cases where the implant needs to be removed. Removing the implant with minimal damage to the surrounding tissues is important. Osteocytes cannot survive below −2 °C, but epithelial cells, fibroblasts, and other surrounding tissue cells can. Remodeling can be triggered by cryotherapy at temperatures that specifically affect osteocyte necrosis. In this study, we aimed to develop a method for reversing the osseointegration mechanism and for protecting the surrounding tissues by bone remodeling induced by CO2 cryotherapy. Materials and Methods: In this study, eight 2.8 mm diameter, one-piece mini implants were used in New Zealand rabbit tibias. Two control and six implants were tested in this study. After 2 months of osseointegration, a reverse torque force method was used to remove all osseointegrated implants at 5, 10, 20, and 30 Ncm. The osseointegration of the implants was proven by periotest measurements. Changes in bone tissue were examined in histological sections stained with toluidine blue after rabbit sacrifice. The number of lacunae with osteocyte, empty lacunae, and lacunae greater than 5 µm and the osteon number in a 10,000 µm2 area were calculated. Cryotherapy was applied to the test implants for 1 min, 2 min, and 5 min. Three implants were subjected to cryotherapy at −40 °C, and the other implants were subjected to cryotherapy at −80 °C. Results: Empty lacunae, filled osteocytes, lacunae >5 µm, and the osteon count around the implant applied at −40 °C were not significantly different from the control implants. The application of −40 °C for 1 min was found to cause minimal damage to the bone cells. The implants, which were applied for 1 min and 2 min, were successfully explanted on the 2nd day with the 5 Ncm reverse torque method. Test implants, which were applied cold for 5 min, were explanted on day 1. Tissue damage was detected in all test groups at −80 °C. Conclusions: The method of removing implants with cryotherapy was found to be successful in −40 °C freeze−thaw cycles applied three times for 1 min. To prove implant removal with cryotherapy, more implant trials should be conducted.
Topics: Animals; Dental Implants; Osseointegration; Rabbits; Tibia; Titanium; Torque
PubMed: 35888569
DOI: 10.3390/medicina58070849 -
BMC Musculoskeletal Disorders Jan 2022Parathyroid hormone, with its anabolic effect on bone formation, has shown excellent outcomes of curing postmenopausal osteoporosis as well as enhancing osseointegration...
Parathyroid hormone enhances gap healing and osseointegration in orthopedic porous coated titanium implants: a correlative micro-computed tomographic, histomorphometric and biomechanical analysis.
BACKGROUND
Parathyroid hormone, with its anabolic effect on bone formation, has shown excellent outcomes of curing postmenopausal osteoporosis as well as enhancing osseointegration around orthopaedic and stomatologic implants.The purpose of the present study is to test if low-dose intermittent PTH (1-34) treatment could achieve a satisfactory osseointegration in 2-mm peri-implant gaps, as to provide a new idea for improving the stability of such prosthesis, which will be of great clinical value.
METHODS
A custom-made titanium implant was implanted on the calvarium of New Zealand White rabbits. 48 male rabbits were randomly divided into control and PTH group. PTH group received subcutaneous injection of PTH (20 μg/day, 5 days/week). Animals were sacrificed at 4 and 8 weeks after surgery. Quantitative micro-computed tomography, histology and biomechanical pull-out testing were performed to evaluate the gap healing at implantation site.
RESULTS
Analysis of micro-computed tomography demonstrated that PTH group achieved more new bone formation in 2-mm gaps and on bone-implant interface. Quantitatively, significant differences were observed between two groups in regard to BIC and BV/TV at each time-point. Histological staining revealed that PTH group had a superiority in trabecular number, thickness, separation and better osseointegration compared to control group. As for biomechanical pull-out testing, PTH group also showed significant improvement of ultimate force than control group.
CONCLUSIONS
Low-dose intermittent administration of PTH for 4 and 8 weeks enhances early osseointegration and fixation of orthopedic implants surrounded by a 2-mm gap in terms of increased bone regeneration and mechanical stability. These findings suggest PTH a potential for reducing the postoperative complications of implants by improving bone healing at peri-implant gaps.
Topics: Animals; Male; Orthopedics; Osseointegration; Parathyroid Hormone; Porosity; Prostheses and Implants; Rabbits; Titanium; X-Ray Microtomography
PubMed: 34980060
DOI: 10.1186/s12891-021-04917-y -
Bone Aug 2020Spatiotemporal implant-bone biomechanics and mechanoadaptive strains in peri-implant tissue are poorly understood. Physical and chemical characteristics of an...
Spatiotemporal implant-bone biomechanics and mechanoadaptive strains in peri-implant tissue are poorly understood. Physical and chemical characteristics of an implant-bone complex (IBC) were correlated in three-dimensional space (along the length and around a dental implant) to gather insights into time related integration of the implant with the cortical portion of a jaw bone in a rat. Rats (N = 9) were divided into three experimental groups with three rats per time point; 3-, 11-, and 24-day. All rats were fed crumbled hard pellets mixed with water (soft-food diet) for the first 3 days followed by a hard-food diet with intact hard-food pellets (groups of 11- and 24-day only). Biomechanics of the IBCs harvested from rats at each time point was evaluated by performing mechanical testing in situ in tandem with X-ray imaging. The effect of physical association (contact area) of a loaded implant with adapting peri-implant tissue, and resulting strain within was mapped by using digital volume correlation (DVC) technique. The IBC stiffness at respective time points was correlated with mechanical strain in peri-implant tissue. Results illustrated that IBC stiffness at 11-day was lower than that observed at 3-day. However, at 24-day, IBC stiffness recovered to that which was observed at 3-day. Correlative microscopy and spectroscopy illustrated that the lower IBC stiffness was constituted by softer and less mineralized peri-implant tissue that contained varying expressions of osteoconductive elements. Lower IBC stiffness observed at 11-day was constituted by less mineralized peri-implant tissue with osteoconductive elements that included phosphorus (P) which was co-localized with higher expression of zinc (Zn), and lower expression of calcium (Ca). Higher IBC stiffness at 24-day was constituted by mineralized peri-implant tissue with higher expressions of osteoconductive elements including Ca and P, and lower expressions of Zn. These spatiotemporal correlative maps of peri-implant tissue architecture, heterogeneous distribution of mineral density, and elemental colocalization underscore mechanoadaptive physicochemical properties of peri-implant tissue that facilitate functional osseointegration of an implant. These results provided insights into 1) plausible "prescription" of mechanical loads as an osteoinductive "therapeutic dose" to encourage osteoconductive elements in the peri-implant tissue that would facilitate functional osseointegration of the implant; 2) a "critical temporal window" between 3 and 11 days, and perhaps it is this acute phase during which key candidate regenerative molecules can be harnessed to accelerate osseointegration of an implant under load.
Topics: Animals; Biomechanical Phenomena; Dental Implants; Osseointegration; Rats; Titanium
PubMed: 32335376
DOI: 10.1016/j.bone.2020.115375 -
International Journal of Nanomedicine 2023Three-dimensional (3D) printing is serving as the most promising approach to fabricate personalized titanium (Ti) implants for the precise treatment of complex bone... (Review)
Review
Three-dimensional (3D) printing is serving as the most promising approach to fabricate personalized titanium (Ti) implants for the precise treatment of complex bone defects. However, the bio-inert nature of Ti material limits its capability for rapid osseointegration and thus influences the implant lifetime in vivo. Despite the macroscale porosity for promoting osseointegration, 3D-printed Ti implant surface morphologies at the nanoscale have gained considerable attention for their potential to improve specific outcomes. To evaluate the influence of nanoscale surface morphologies on osseointegration outcomes of 3D-printed Ti implants and discuss the available strategies, we systematically searched evidence according to the PRISMA on PubMed, Embase, Web of Science, and Cochrane (until June 2022). The inclusion criteria were in vivo (animal) studies reporting the osseointegration outcomes of nanoscale morphologies on the surface of 3D-printed Ti implants. The risk of bias (RoB) was assessed using the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE's) tool. The quality of the studies was evaluated using the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines. (PROSPERO: CRD42022334222). Out of 119 retrieved articles, 9 studies met the inclusion criteria. The evidence suggests that irregular nano-texture, nanodots and nanotubes with a diameter of 40-105nm on the surface of porous/solid 3D-printed Ti implants result in better osseointegration and vertical bone ingrowth compared to the untreated/polished ones by significantly promoting cell adhesion, matrix mineralization, and osteogenic differentiation through increasing integrin expression. The RoB was low in 41.1% of items, unclear in 53.3%, and high in 5.6%. The quality of the studies achieved a mean score of 17.67. Our study demonstrates that nanostructures with specific controlled properties on the surface of 3D-printed Ti implants improve their osseointegration. However, given the small number of studies, the variability in experimental designs, and lack of reporting across studies, the results should be interpreted with caution.
Topics: Animals; Osseointegration; Osteogenesis; Titanium; Prostheses and Implants; Printing, Three-Dimensional; Surface Properties; Porosity
PubMed: 37525692
DOI: 10.2147/IJN.S409033 -
Orthopaedic Surgery May 2014The clinical outcome of lumbar spinal fusion is correlated with achievement of bony fusion. Improving interbody implant bone on-growth and in-growth may enhance fusion,... (Review)
Review
The clinical outcome of lumbar spinal fusion is correlated with achievement of bony fusion. Improving interbody implant bone on-growth and in-growth may enhance fusion, limiting pseudoarthrosis, stress shielding, subsidence and implant failure. Polyetheretherketone (PEEK) and titanium (Ti) are commonly selected for interbody spacer construction. Although these materials have desirable biocompatibility and mechanical properties, they require further modification to support osseointegration. Reports of extensive research on this topic are available in biomaterial-centric published reports; however, there are few clinical studies concerning surface modification of interbody spinal implants. The current article focuses on surface modifications aimed at fostering osseointegration from a clinician's point of view. Surface modification of Ti by creating rougher surfaces, modifying its surface topography (macro and nano), physical and chemical treatment and creating a porous material with high interconnectivity can improve its osseointegrative potential and bioactivity. Coating the surface with osteoconductive materials like hydroxyapatite (HA) can improve osseointegration. Because PEEK spacers are relatively inert, creating a composite by adding Ti or osteoconductive materials like HA can improve osseointegration. In addition, PEEK may be coated with Ti, effectively bio-activating the coating.
Topics: Benzophenones; Coated Materials, Biocompatible; Humans; Ketones; Osseointegration; Polyethylene Glycols; Polymers; Porosity; Prostheses and Implants; Prosthesis Design; Spinal Fusion; Surface Properties; Titanium
PubMed: 24890288
DOI: 10.1111/os.12098 -
Cells Oct 2022Titanium-based implants are often utilized in oral implantology and craniofacial reconstructions. However, the biological inertness of machined titanium commonly results...
Titanium-based implants are often utilized in oral implantology and craniofacial reconstructions. However, the biological inertness of machined titanium commonly results in unsatisfactory osseointegration. To improve the osseointegration properties, we modified the titanium implants with nanotubular/superhydrophilic surfaces through anodic oxidation and thermal hydrogenation and evaluated the effects of the machined surfaces (M), nanotubular surfaces (Nano), and hydrogenated nanotubes (H-Nano) on osteogenesis and osseointegration in vitro and in vivo. After incubation of mouse bone marrow mesenchymal stem cells on the samples, we observed improved cell adhesion, alkaline phosphatase activity, osteogenesis-related gene expression, and extracellular matrix mineralization in the H-Nano group compared to the other groups. Subsequent in vivo studies indicated that H-Nano implants promoted rapid new bone regeneration and osseointegration at 4 weeks, which may be attributed to the active osteoblasts adhering to the nanotubular/superhydrophilic surfaces. Additionally, the Nano group displayed enhanced osteogenesis in vitro and in vivo at later stages, especially at 8 weeks. Therefore, we report that hydrogenated superhydrophilic nanotubes can significantly accelerate osteogenesis and osseointegration at an early stage, revealing the considerable potential of this implant modification for clinical applications.
Topics: Mice; Animals; Osseointegration; Titanium; Surface Properties; Nanotubes
PubMed: 36359812
DOI: 10.3390/cells11213417 -
Indian Journal of Dental Research :... 2020This systematic review has been undertaken to highlight the unforgettable contributions of Prof. Brånemark Per-Ingvar (PI). It could be understood that reviewing his... (Review)
Review
PURPOSE
This systematic review has been undertaken to highlight the unforgettable contributions of Prof. Brånemark Per-Ingvar (PI). It could be understood that reviewing his work would give an idea of growth of this treatment modality. Materials and Methods: An electronic search on the PubMed/Medline, Ebscohost, and Cochrane database was done using search term "Brånemark PI" to identify his publications. Articles published in English and only related to implants and osseointegration were included. Screening of the titles and abstracts were done according to inclusion criteria and suitable studies were included in the review.
RESULTS
The initial literature search resulted in 187 articles, out of which 92 articles were excluded due to not meeting the inclusion criteria and 16 articles excluded due to non-availability of even abstract also. A total of 79 articles were finally included in this review.
CONCLUSION
Brånemark PI had a great vision of future; who considered edentulism as equal to amputation and came up with the concept of osseointegrated implants to overcome them. The innovations of Brånemark had assured the world that it is very much possible to provide implant-supported prosthesis in any situations for the rehabilitation of the individuals.
Topics: Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Humans; Osseointegration
PubMed: 33753667
DOI: 10.4103/ijdr.IJDR_587_18 -
Journal of Dental Research Dec 2011The success rate of titanium implants for dental and orthopedic applications depends on the ability of surrounding bone tissue to integrate with the surface of the... (Review)
Review
The success rate of titanium implants for dental and orthopedic applications depends on the ability of surrounding bone tissue to integrate with the surface of the device, and it remains far from ideal in patients with bone compromised by physiological factors. The electrical properties and electrical stimulation of bone have been shown to control its growth and healing and can enhance osseointegration. Bone cells are also sensitive to the chemical products generated during corrosion events, but less is known about how the electrical signals associated with corrosion might affect osseointegration. The metallic nature of the materials used for implant applications and the corrosive environments found in the human body, in combination with the continuous and cyclic loads to which these implants are exposed, may lead to corrosion and its corresponding electrochemical products. The abnormal electrical currents produced during corrosion can convert any metallic implant into an electrode, and the negative impact on the surrounding tissue due to these extreme signals could be an additional cause of poor performance and rejection of implants. Here, we review basic aspects of the electrical properties and electrical stimulation of bone, as well as fundamental concepts of aqueous corrosion and its electrical and clinical implications.
Topics: Animals; Bone and Bones; Corrosion; DNA; Dental Alloys; Dental Implants; Dental Stress Analysis; Electric Stimulation; Electricity; Electrochemistry; Humans; Membrane Potentials; Metals; Osseointegration; Osteoblasts; Titanium
PubMed: 21555775
DOI: 10.1177/0022034511408428