Bone-derived titanium coating improvesin vivoimplant osseointegration in an experimental animal model

Effectiveness of biomolecule-based bioactive surfaces, on os-seointegration of titanium dental implants: A systematic review and meta-analysis of in vivo studies

Titanium and alloy osseointegrated implants are used to replace missing teeth; however, some fail and are removed. Modifications of the implant surface with biologically active substances have been proposed. MEDLINE [via Pubmed], Embase and Web of Science were searched with the terms “titanium dental implants”, “surface properties”, “bioactive surface modifications”, “biomolecules”, “BMP”, “antibacterial agent”, “peptide”, “collagen”, “grown factor”, “osseointegration”, “bone apposition”, “osteogenic”, “osteogenesis”, “new bone formation”, “bone to implant contact”, “bone regeneration” and “in vivo studies”, until May 2022. A total of 10,697 references were iden-tified and 26 were included to analyze 1,109 implants, with follow-ups from 2 to 84 weeks. The ARRIVE guidelines and the SYRCLE tool were used to evaluate the methodology and scientific evidence. A meta-analysis was performed (RevMan 2020 software, Cochane Collaboration) with random effects that evaluated BIC at 4 weeks, with subgroups for the different coatings. The heterogeneity of the pooled studies was very high (95% CI, I2 = 99%). The subgroup of BMPs was the most favorable to coating. Surface modification of Ti implants by organic bioactive molecules seems to favor osseointegration in the early stages of healing, but long-term studies are necessary to corroborate the results of the experimental studies.

Surface coating of orthopedic implant to enhance the osseointegration and reduction of bacterial colonization: a review

The use of orthopedic implants in surgical technology has fostered restoration of physiological functions. Along with successful treatment, orthopedic implants suffer from various complications and fail to offer functions correspondent to native physiology. The major problems include aseptic and septic loosening due to bone nonunion and implant site infection due to bacterial colonization. Crucial advances in material selection in the design and development of coating matrixes an opportunity for the prevention of implant failure. However, many coating materials are limited in in-vitro testing and few of them thrive in clinical tests. The rate of implant failure has surged with the increasing rates of revision surgery creating physical and sensitive discomfort as well as economic burdens. To overcome critical pathogenic activities several systematic coating techniques have been developed offering excellent results that combat infection and enhance bone integration. This review article includes some more common implant coating matrixes with excellent in vitro and in vivo results focusing on infection rates, causes, complications, coating materials, host immune responses and significant research gaps. This study provides a comprehensive overview of potential coating technology, with functional combination coatings which are focused on ultimate clinical practice with substantial improvement on in-vivo tests. This includes the development of rapidly growing hydrogel coating techniques with the potential to generate several accurate and precise coating procedures.

Effect of Pore Size on the Physicochemical Properties and Osteogenesis of Ti6Al4V Porous Scaffolds with Bionic Structure

Ti6Al4V is widely used in implants in the fields of orthopedics and dentistry due to its high compressive strength and good biocompatibility. Nevertheless, Ti6Al4V has a certain degree of biological inertness and the elastic modulus of Ti6Al4V is much higher than the cortex and trabecular bone. In this study, we designed and printed a new type of pore size Ti6Al4V with like-trabecular structure scaffold (the pore size is 800/900/1000 μm, named P8/P9/P10, respectively) with electron beam melting (EBM). Its elastic modulus, compressive strength, and other physical and chemical properties, as well as cell adhesion, proliferation, and differentiation ability and in vitro biological properties were studied. The physical and chemical performance test results showed that as the pore size increased, the surface wettability increased and the elastic modulus decreased. As the pore size increased, F-actin and alkaline phosphatase (ALP) increased significantly, and osteogenesis-related genes including BMP2, OCN, RUNX2, and ALP were upregulated significantly. The reason may be that the components on the Ti6Al4V pore size may have an influence on intracellular signal conversion and then change the mode of cell proliferation and diffusion. In summary, the like-trabecular porous structure can effectively reduce the elastic modulus of metal materials, thereby avoiding stress concentration and promoting the adhesion and proliferation of osteoblasts. Porous materials with larger pores are more conducive to the proliferation and differentiation of osteoblasts. The irregular porous Ti6Al4V scaffold prepared by the EBM technology has good mechanical properties and the potential to promote adhesion, proliferation, and differentiation of osteoblasts, and has the possibility of application in the field of implantation.

Improved osteogenic differentiation of human amniotic mesenchymal stem cells on gradient nanostructured Ti surface

Titanium (Ti) and Ti-based alloys are widely used in the manufacture of dental and orthopedic implants. However, how to improve their osteogenic differentiation ability is still a key issue to be resolved. In this study, gradient nanostructured surface (GNS) samples were prepared by surface mechanical grinding treatment, and coarse-grained (CG) samples were obtained by recrystallization annealing, making sure that the two kinds of specimens had similar roughness. Then, human amniotic mesenchymal stem cells (hAMSCs) were cocultured with the two kinds of Ti to investigate the material effects on the cellular functions. The results demonstrated that the grains with size ~56 nm were formed on the surface of the GNS Ti, and the grain size gradually increases from the sample surface to interior. Compared to the CG samples, the GNS ones could make the adhesion effect of the hAMSCs better, and promote the cell proliferation and osteogenic differentiation more significantly, the preliminary mechanism of which might be due to their specific nanostructure, the thicker oxide layer formed on their surface and the enhanced hardness. Our results indicated that the gradient nanostructured Ti materials could enhance both osteogenic differentiation and mechanical properties, which may possess broader applications in bone tissue engineering and clinical implanting.

Influence of Implant Shape (Tapered vs Cylindrical) on the Survival of Dental Implants Placed in the Posterior Maxilla: A Systematic Review

PURPOSE

The aim of this review was to assess the effect of implant shape (tapered vs cylindrical) on the survival of dental implants placed in the posterior maxilla.

METHODS

Databases were searched from 1977 up to and including February 2015 using various key words. Only original clinical studies were included. Experimental studies, letters to the editor, review articles, case reports, and unpublished literature were excluded. The pattern of the present review was customized to mainly summarize the relevant information.

RESULTS

Five studies were included. The number of patients included ranged between 4 and 29 participants. In total, 7 to 72 implants were placed in the posterior maxilla. Tapered and cylindrical shaped implants were placed in 1 and 1 study, respectively. In 1 study, both 41 tapered and cylindrical implant were placed. In all studies, rough-surfaced and threaded implants were used. Three studies reported the diameter and lengths of implants placed, which ranged between 3.75 to 4 mm and 10 to 20 mm, respectively. The mean follow-up period and survival rate of implants ranged between 19 and 96 months and 84.2% to 100%, respectively. In 1 study, implants were placed subcrestally in the posterior maxilla. Guided bone regeneration was performed in none of the studies. In all studies, participants were nonsmokers and were systemically healthy.

CONCLUSIONS

There is no influence of implant shape on the survival of implants placed in the posterior maxilla.

A Xenogenic Bone Derivative as a Potential Adjuvant for Bone Regeneration and Implant Osseointegration: An In Vitro Study

Several clinical conditions may limit the success of bone regeneration and/or implant osseointegration. For this reason, many compounds have been tested for their ability to stimulate this biological process. Synthetic hydroxyapatite (HA), mimicking natural bone hydroxyapatite, and extra-cellular matrix proteins, such as type I collagen, are potential candidates. However, the synthetic origin of HA and the denaturing conditions required for extracting collagen from skin and derma are sources of potential drawbacks. This study examines the in vitro effects of a natural bone derivative (NBD) extracted from equine bone and containing both natural, non-synthetic bone hydroxyapatite and native, non-denatured, type I bone collagen as a possible active compound for stimulating bone regeneration and implant osseointegration. The activity of NBD was tested on bone marrow stromal cells (BMSCs), evaluating their growth/viability by the methylthiazol tetrazolium (MTT) assay and their migration potential by a scratch assay. Moreover, expression of the hyaluronic acid receptor (CD44) and the C-X-C chemokine receptor type 4 (CXCR4, CD184) on the surface of BMSCs was assessed by flow cytometry, and the release of Transforming Growth Factor (TGF)-β, Interleukin (IL)-1α and IL-6 was quantified using an enzyme-linked immunosorbent assay (ELISA). The effect of NBD-coated implants on human osteoblasts was tested by measuring alkaline phosphatase (ALP) activity with the p-nitrophenyl phosphate (pNPP) degradation test. NBD stimulated BMSC growth/viability, migration, CD184 surface expression and the release of TGF-β1. NBD-coated implants increased ALP activity of human osteoblasts. These results indicate that NBD may be an adjuvant to accelerate both bone regeneration and osseointegration.

Bone tissue response to plasma-nitrided titanium implant surfaces

A current goal of dental implant research is the development of titanium (Ti) surfaces to improve osseointegration. Plasma nitriding treatments generate surfaces that favor osteoblast differentiation, a key event to the process of osteogenesis. Based on this, it is possible to hypothesize that plasma-nitrided Ti implants may positively impact osseointegration.