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Journal of Neuroengineering and... Mar 2022Electrical stimulation has shown to be a promising approach for promoting osseointegration in bone anchoring implants, where osseointegration defines the biological... (Review)
Review
Electrical stimulation has shown to be a promising approach for promoting osseointegration in bone anchoring implants, where osseointegration defines the biological bonding between the implant surface and bone tissue. Bone-anchored implants are used in the rehabilitation of hearing and limb loss, and extensively in edentulous patients. Inadequate osseointegration is one of the major factors of implant failure that could be prevented by accelerating or enhancing the osseointegration process by artificial means. In this article, we reviewed the efforts to enhance the biofunctionality at the bone-implant interface with electrical stimulation using the implant as an electrode. We reviewed articles describing different electrode configurations, power sources, and waveform-dependent stimulation parameters tested in various in vitro and in vivo models. In total 55 English-language and peer-reviewed publications were identified until April 2020 using PubMed, Google Scholar, and the Chalmers University of Technology Library discovery system using the keywords: osseointegration, electrical stimulation, direct current and titanium implant. Thirteen of those publications were within the scope of this review. We reviewed and compared studies from the last 45 years and found nonuniform protocols with disparities in cell type and animal model, implant location, experimental timeline, implant material, evaluation assays, and type of electrical stimulation. The reporting of stimulation parameters was also found to be inconsistent and incomplete throughout the literature. Studies using in vitro models showed that osteoblasts were sensitive to the magnitude of the electric field and duration of exposure, and such variables similarly affected bone quantity around implants in in vivo investigations. Most studies showed benefits of electrical stimulation in the underlying processes leading to osseointegration, and therefore we found the idea of promoting osseointegration by using electric fields to be supported by the available evidence. However, such an effect has not been demonstrated conclusively nor optimally in humans. We found that optimal stimulation parameters have not been thoroughly investigated and this remains an important step towards the clinical translation of this concept. In addition, there is a need for reporting standards to enable meta-analysis for evidence-based treatments.
Topics: Animals; Bone-Implant Interface; Electric Stimulation; Humans; Osseointegration; Prostheses and Implants; Surface Properties; Titanium
PubMed: 35313892
DOI: 10.1186/s12984-022-01005-7 -
Periodontology 2000 Oct 2022Historically, there has been broad consensus that osseointegration represents a homeostasis between a titanium dental implant and the surrounding bone, and that the... (Review)
Review
Historically, there has been broad consensus that osseointegration represents a homeostasis between a titanium dental implant and the surrounding bone, and that the crestal bone loss characteristic of peri-implantitis is a plaque-induced inflammatory process. However, this notion has been challenged over the past decade by proponents of a theory that considers osseointegration an inflammatory process characterized by a foreign body reaction and peri-implant bone loss as an exacerbation of this inflammatory response. A key difference in these two schools of thought is the perception of the relative importance of dental plaque in the pathogenesis of crestal bone loss around implants, with obvious implications for treatment. This review investigates the evidence for a persistent foreign body reaction at osseointegrated dental implants and its possible role in crestal bone loss characteristic of peri-implantitis. Further, the role of implant-related material release within the surrounding tissue, particularly titanium particles and corrosion by-products, in the establishment and progression in peri-implantitis is explored. While it is acknowledged that these issues require further investigation, the available evidence suggests that osseointegration is a state of homeostasis between the titanium implant and surrounding tissues, with little evidence that a persistent foreign body reaction is responsible for peri-implant bone loss after osseointegration is established. Further, there is a lack of evidence for a unidirectional causative role of corrosion by-products and titanium particles as possible non-plaque related factors in the etiology of peri-implantitis.
Topics: Alveolar Bone Loss; Dental Implants; Foreign Bodies; Foreign-Body Reaction; Humans; Osseointegration; Peri-Implantitis; Titanium
PubMed: 35916872
DOI: 10.1111/prd.12456 -
Lasers in Medical Science Feb 2022The aim of this work was to perform an integrative literature review on the influence of laser irradiation on zirconia implants to enhance surface topographic aspects... (Review)
Review
The aim of this work was to perform an integrative literature review on the influence of laser irradiation on zirconia implants to enhance surface topographic aspects and the biological response for osseointegration. An electronic search was carried out on the PubMed database using the following search terms: "zirconia" AND "laser" AND "surface modification" OR "surface treatment" AND "dental implants" OR "bone" OR "osteoblast" OR "osseointegration." Of the identified articles, 12 studies were selected in this review. Results reported that the laser irradiation was capable of promoting changes on the zirconia surfaces regarding topographic aspects, roughness, and wettability. An increase in roughness was recorded at micro- and nano-scale and it resulted in an enhanced wettability and biological response. Also, adhesion, spreading, proliferation, and differentiation of osteogenic cells were also enhanced after laser irradiation mainly by using a femtosecond laser at 10nJ and 80 MHz. After 3 months of osseointegration, in vivo studies in dogs revealed a similar average percentage of bone-to-implant contact (BIC) on zirconia surfaces (around 47.9 ± 16%) when compared to standard titanium surfaces (61.73 ±16.27%), denoting that there is no significant difference between such different materials. The laser approach revealed several parameters that can be used for zirconia surface modification such as irradiation intensity, time, and frequency. Laser irradiation parameters can be optimized and well-controlled to reach desirable surface morphologic aspects and biological response concerning the osseointegration process.
Topics: Animals; Dental Implants; Dental Prosthesis Design; Dogs; Lasers; Osseointegration; Surface Properties; Titanium; Zirconium
PubMed: 35022871
DOI: 10.1007/s10103-021-03475-y -
Calcified Tissue International Jan 2022Bone metabolism may be adversely affected in metabolic diseases such as obesity and metabolic syndrome, which are characterised by weight gain, due to the expansion of... (Review)
Review
Bone metabolism may be adversely affected in metabolic diseases such as obesity and metabolic syndrome, which are characterised by weight gain, due to the expansion of adipose tissue deposits. As an important regulator of energy metabolism, adipose tissues synthesise and secrete several key regulatory adipokines that influence a range of metabolic functions. This narrative review outlines the evidence for the mechanisms by which adipose tissue dysfunction may alter bone metabolism prior to the development of frank hyperglycaemia and presents the emerging evidence for the impact of diet-induced expansion of adipose tissue on implant osseointegration. Successful osseointegration requires normal bone cell function, and the expansion of adipose tissue deposits results in dysregulated adipokine production favouring an increase in pro-inflammatory adipokines, contributing to the development of a chronic inflammatory state and insulin resistance. The increase in inflammatory cytokines promotes the growth and differentiation of osteoclasts indirectly through the modulation of osteoblastic RANKL production and directly by reducing osteoclast apoptosis and increased osteoclastic expression of RANK. Conversely, the suppression of osteoblastic regulatory genes results in reduced osteoblast numbers and function contributing to compromised bone turnover. Compromised osseointegration has been established in hyperglycaemia; however, as discussed in this review, it may not be the only driver of altered bone metabolism. The incidence of metabolic disease in the community is rising, patients may present for implant treatment with undiagnosed, underlying changes to bone cell metabolism due to adipose tissue dysmetabolism.
Topics: Adipokines; Adipose Tissue; Humans; Insulin Resistance; Obesity; Osseointegration
PubMed: 34374815
DOI: 10.1007/s00223-021-00899-0 -
Prosthetics and Orthotics International Apr 2022A patient (the first author) with a preexisting right side transfemoral amputation (20 years before) had osseointegration surgery. She was assigned a physiotherapist...
A patient (the first author) with a preexisting right side transfemoral amputation (20 years before) had osseointegration surgery. She was assigned a physiotherapist (the second author) and began a rehabilitation program. We provide a unique insight into the first 18 months of rehabilitation after insertion of an osseointegration bone anchor from a physiotherapist and patient perspective with the intention of informing practitioners, patients, and potential patients about the experience and identifying potential areas for improvements in the rehabilitation protocol. The experience was tracked by both the patient and the physiotherapist for 18 months post-surgery. The physiotherapist followed a specific protocol with the patient in the first part of the recovery stage. The patient kept records of subjective experiences over the same period. Loading and physiotherapy were completed in line with the protocol for the first 12-week phase including successful fitting of the prosthetic limb on day 12. Physiotherapy and other interventions evolved to meet the patient's needs over the 18-month period. The patient progressed through her rehabilitation, and new data about the patient's experience were gathered. Following the protocol enabled the patient to progress through her rehabilitation. Unforeseen setbacks (abscesses and inflammation/entheseopathies) slowed this process to some extent. Findings from these data can be used to help inform and improve future rehabilitations for patients with osseointegration: patients can be advised about possible setbacks and physiotherapy, and other interventions can be developed to treat should these problems arise.
Topics: Amputation, Surgical; Female; Humans; Osseointegration; Physical Therapy Modalities
PubMed: 35412525
DOI: 10.1097/PXR.0000000000000055 -
Journal of the Mechanical Behavior of... Mar 2020With the need of rapid healing and long-term stability of dental implants, the existing Ti-based implant materials do not meet completely the current expectation of... (Review)
Review
With the need of rapid healing and long-term stability of dental implants, the existing Ti-based implant materials do not meet completely the current expectation of patients. Low elastic modulus Ti-alloys have shown superior biocompatibility and can achieve comparable or even faster bone formation in vivo at the interface of bone and the implant. Porous structured Ti alloys have shown to allow rapid bone ingrowth through their open structure and to achieve anchorage with bone tissue by increasing the bone-implant interface area. In addition to the mechanical properties of implant materials, the design of the implant body can be used to optimize load transfer and affect the ultimate results of osseointegration. The aim of this narrative review is to define the mechanical properties of dental implants, summarize the relationship between implant stability and osseointegration, discuss the effect of metallic implant mechanical properties (e.g. stiffness and porosity) on the bone response based on existing in vitro and in vivo information, and analyze load transfer through mechanical properties of the implant body. This narrative review concluded that although several studies have presented the advantages of low elastic modulus or high porosity alloys and their effect on osseointegration, further in vivo studies, especially long-term observational studies are needed to justify these novel materials as a replacement for current Ti-based implant materials.
Topics: Bone-Implant Interface; Dental Implants; Humans; Osseointegration; Porosity; Surface Properties; Titanium
PubMed: 32090904
DOI: 10.1016/j.jmbbm.2019.103574 -
Biomaterials Advances Dec 2022Osseointegration is the direct and intimate contact between mineralized tissue and titanium implant at the bone-implant interface. Early establishment and stable... (Review)
Review
Osseointegration is the direct and intimate contact between mineralized tissue and titanium implant at the bone-implant interface. Early establishment and stable maintenance of osseointegration is the key to long-term implant success. However, in patients with compromised conditions such as osteoporosis and patients beginning early load-bearing activities such as walking, lower osseointegration around titanium implants is often observed, which might result in implant early failure. Gene-activated implants show an exciting prospect of combining gene delivery and biomedical implants to solve the problems of poor osseointegration formation, overcoming the shortcomings of protein therapy, including rapid degradation and overdose adverse effects. The conception of gene-activated titanium implants is based on "gene-activated matrix" (GAM), which means scaffolds using non-viral vectors for in situ gene delivery to achieve a long-term and efficient transfection of target cells. Current preclinical studies in animal models have shown that plasmid DNA (pDNA), microRNA (miRNA), and small interference RNA (siRNA) functionalized titanium implants can enhance osseointegration with safety and efficiency, leading to the expectation of applying this technique in dental and orthopedic clinical scenarios. This review aims to comprehensively summarize fabrication strategies, current applications, and futural outlooks of gene-activated implants, emphasizing nucleic acid targets, non-viral vectors, implant surface modification techniques, nucleic acid/vector complexes loading strategies.
Topics: Animals; Osseointegration; Titanium; Bone-Implant Interface; Prostheses and Implants; Nucleic Acids
PubMed: 36327825
DOI: 10.1016/j.bioadv.2022.213176 -
Die Rehabilitation Oct 2021
Topics: Germany; Osseointegration; Prosthesis Fitting
PubMed: 34655067
DOI: 10.1055/a-1491-6674 -
Dental Materials : Official Publication... Oct 2021The present review article aimed to discuss the recent technologies employed for the development of dental implants, mainly regarding innovative surface treatments and... (Review)
Review
OBJECTIVES
The present review article aimed to discuss the recent technologies employed for the development of dental implants, mainly regarding innovative surface treatments and alternative alloys, emphasizing the bio-tribocorrosion processes.
METHODS
An electronic search applying specific MeSH terms was carried out in PubMed and Google Scholar databases to collect data until August 2021, considering basic, pre-clinical, clinical and review studies. The relevant articles (n=111), focused on innovative surface treatments for dental implants and their potential undesirable biological effects, were selected and explored.
RESULTS
Novel texturization methodologies for dental implants clearly provided superficial and structural atomic alterations in micro- and nanoscale, promoting different mechanical-chemical interactions when applied in the clinical set. Some particulate metals released from implant surfaces, their degradation products and/or contaminants exhibited local and systemic reactions after implant installation and osseointegration, contributing to unexpected treatment drawbacks and adverse effects. Therefore, there is an urgent need for development of pre-clinical and clinical platforms for screening dental implant devices, to predict the biointerface reactions as early as possible during the development phases.
SIGNIFICANCE
Modern surface treatments and innovative alloys developed for dental implants are not completely understood regarding their integrity during long-term clinical function, especially when considering the bio-tribocorrosion process. From this review, it is possible to assume that degradation and contamination of dental surfaces might be associated within peri-implant inflammation and cumulative long-lasting systemic toxicity. The in-depth comprehension of the biointerface modifications on these novel surface treatments might preclude unnecessary expenses and postoperative complications involving osseointegration failures.
Topics: Alloys; Dental Alloys; Dental Implants; Dental Prosthesis Design; Osseointegration; Surface Properties; Titanium
PubMed: 34426019
DOI: 10.1016/j.dental.2021.08.008 -
Molecules (Basel, Switzerland) Dec 2020The contribution of epigenetic mechanisms as a potential treatment model has been observed in cancer and autoimmune/inflammatory diseases. This review aims to put... (Review)
Review
The contribution of epigenetic mechanisms as a potential treatment model has been observed in cancer and autoimmune/inflammatory diseases. This review aims to put forward the epigenetic mechanisms as a promising strategy in implant surface functionalization and modification of biomaterials, to promote better osseointegration and bone regeneration, and could be applicable for alveolar bone regeneration and osseointegration in the future. Materials and Methods: Electronic and manual searches of the literature in PubMed, MEDLINE, and EMBASE were conducted, using a specific search strategy limited to publications in the last 5 years to identify preclinical studies in order to address the following focused questions: (i) Which, if any, are the epigenetic mechanisms used to functionalize implant surfaces to achieve better osseointegration? (ii) Which, if any, are the epigenetic mechanisms used to functionalize biomaterials to achieve better tissue regeneration? Findings from several studies have emphasized the role of miRNAs in functionalizing implants surfaces and biomaterials to promote osseointegration and bone regeneration, respectively. However, there are scarce data on the role of DNA methylation and histone modifications for these specific applications, despite being commonly applied in cancer research. Studies over the past few years have demonstrated that biomaterials are immunomodulatory rather than inert materials. In this context, epigenetics can act as next generation of advanced treatment tools for future regenerative techniques. Yet, there is a need to evaluate the efficacy/cost effectiveness of these techniques in comparison to current standards of care.
Topics: Animals; Biocompatible Materials; Bone Regeneration; Epigenesis, Genetic; Humans; Osseointegration
PubMed: 33322654
DOI: 10.3390/molecules25245879