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Purpose: The purpose of this study was to show the full evolution of bone anchorage caused by the growth of secondary stability and to determine which empirical model would provide the best quantitative description of this growth. Materials and Methods: The retention and anchorage of machined (M), grit-blasted and dual acid etched (BAE), and BAE implants with discrete crystals of calcium phosphate (+DCD) were evaluated with both ex vivo and in vivo methods. Ex vivo evaluation of implant retention was tested by measuring the force required to pull implants out of blood-filled osteotomies formed in bovine bone for up to 1 hour. In vivo measurements of bone anchorage were evaluated by reverse torque testing of implants placed in the proximal metaphysis of rat tibiae up to 28 days after initial placement. Four models were fit to the reverse torque results, and fits were evaluated by Bayesian and Akaike information criteria (BIC and AIC) and analysis of variance (ANOVA). Results: AIC and BIC were 655.53 and 684.78, 472.53 and 512.74, 477.40 and 513.96, and 470.60 and 507.16 for the monomolecular, Richards, Gompertz, and logistic curves, respectively. Comparison of the Richards and logistic curves by analysis of variance (ANOVA) resulted in a P value of .78. A comparison of the three implant types using the logistic curve found that M implants had an earlier inflection point compared with BAE implants (P = .038), and the BAE+DCD implants had the greatest peak anchorage and were significantly greater than both M (P < .0001) and BAE implants (P = .005). Conclusion: Bone anchorage was found to follow sigmoidal growth, which was best described by the logistic function. Further comparison of the fit values for the logistic curve shows that both overall anchorage and timing of bone anchorage are influenced by implant surface topography. [ABSTRACT FROM AUTHOR]

Chemical composition and physical parameters of the implant surface, such as roughness, regulate the cellular response leading to implant bone osseointegration. Possible implant surface modifications include anodization or the plasma electrolytic oxidation (PEO) treatment process that produces a thick and dense oxide coating superior to normal anodic oxidation. Experimental modifications with Plasma Electrolytic Oxidation (PEO) titanium and titanium alloy Ti6Al4V plates and PEO additionally treated with low-pressure oxygen plasma (PEO-S) were used in this study to evaluate their physical and chemical properties. Cytotoxicity of experimental titanium samples as well as cell adhesion to their surface were assessed using normal human dermal fibroblasts (NHDF) or L929 cell line. Moreover, the surface roughness, fractal dimension analysis, and texture analysis were calculated. Samples after surface treatment have substantially improved properties compared to the reference SLA (sandblasted and acid-etched) surface. The surface roughness (Sa) was 0.59–2.38 µm, and none of the tested surfaces had cytotoxic effect on NHDF and L929 cell lines. A greater cell growth of NHDF was observed on the tested PEO and PEO-S samples compared to reference SLA sample titanium. [ABSTRACT FROM AUTHOR]

Laser-induced periodic surface structures (LIPSS) are the sub-wavelength periodic nanostructures generated by the femtosecond laser. Implant topography and its nanostructural changes can be important for biomedical applications. In order to compare the surface topography of different implants, appropriate mathematical and physical descriptive methods should be provided. The aim of the study was to evaluate the experimental LIPSS-based—Low Spatial Frequency LIPSS (LSFL) dental implant surfaces. Novel methods of surface analysis, such as Fractal Dimension Analysis and Texture Analysis, were compared to the standard surface roughness evaluation. Secondary, cell viability, and attachment tests were applied in order to evaluate the biological properties of the new titanium surface and to compare their correlation with the physical properties of the new surfaces. A Normal Human Dermal Fibroblast (NHDF) cytotoxicity test did not show an impact on the vitality of the cells. Our study has shown that the laser LIPSS implant surface modifications significantly improved the cell adhesion to the tested surfaces. We observed a strong correlation of adhesion and the growth of cells on the tested surface, with an increase in implant surface roughness with the best results for the moderately rough (2 μm) surfaces. Texture and fractal dimension analyses are promising methods to evaluate dental implants with complex geometry. [ABSTRACT FROM AUTHOR]

Periostin is a matricellular protein highly expressed in periodontal ligament and periostium and has been shown to be required for tissue development and maintenance. We showed that the adhesion of murine osteoblastic MC3T3 cells to thiolated hyaluronic acid/polyethyleneglycol hydrogels was greatly improved by enrichment with periostin. Polished or sand-blasted/acid-etched (SLA) commercially pure titanium surfaces were also coated with this protein and periostin ameliorated cell adhesion and dramatically affected cell morphology on both surfaces, as assessed at fluorescence microscopy, scanning electron microscopy, and chemiluminescence-based viability assay. Moreover, periostin increased the expression of alkaline phosphatase, osteoprotegerin, connective tissue growth factor, collagen 1a1, osteocalcin, Runx2, and osterix transcription factors on smooth surfaces. However, it did not affect, or even decreased, the expression of these genes on SLA discs. Transcript levels for connexin 43 were greatly increased on both surfaces in the presence of periostin. Taken together, these results show that periostin coatings can be a viable approach to improve cell adhesion and differentiation on implantable biomaterials. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3855-3861, 2014. [ABSTRACT FROM AUTHOR]

Abstract: The use of pulsed electromagnetic fields (PEMFs) is a promising approach to promote osteogenesis. However, few studies have reported the effects of this technique on the osseointegration of endosseous implants, especially with regard to different implant topographies. We focused on how the initial interaction between cells and the titanium surface is enhanced by a PEMF and the possible regulatory mechanisms in this study. Rat osteoblasts were cultured on three types of titanium surfaces (Flat, Micro and Nano) under PEMF stimulation or control conditions. Protein adsorption was significantly increased by the PEMF. The number of osteoblasts attached to the surfaces in the PEMF group was substantially greater than that in the control group after 1.5h incubation. PEMF stimulation oriented the osteoblasts perpendicular to the electromagnetic field lines and increased the number of microfilaments and pseudopodia formed by the osteoblasts. The cell proliferation on the implant surfaces was significantly promoted by the PEMF. Significantly increased extracellular matrix mineralization nodules were observed under PEMF stimulation. The expression of osteogenesis-related genes, including BMP-2, OCN, Col-1,ALP, Runx2 and OSX, were up-regulated on all the surfaces by PEMF stimulation. Our findings suggest that PEMFs enhance the osteoblast compatibility on titanium surfaces but to different extents with regard to implant surface topographies. The use of PEMFs might be a potential adjuvant treatment for improving the osseointegration process. [Copyright &y& Elsevier]

Coating characteristics of dental implants such as composition and topography regulate cell response during implant healing. The aim of this study was to assess how surface topography can affect osteogenic differentiation of mesenchymal stem cells (MSCs) by analyzing the expression levels of bone-related genes and MSCs marker. Thirty disk-shaped, commercially pure Grade 2 titanium samples (10 × 2 mm) with 3 different surface topographies (DENTSPLY-Friadent GmbH, Mannheim, Germany) were used in the present study: 10 Ti machined disks (control), 10 Ti sandblasted and acid-etched disks (DPS) and 10 sandblasted and acid-etched disks at high temperature (Plus). Samples were processed for real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis. By comparing machined and Plus disks, quantitative real-time RT-PCR showed a significant reduction of the bone-related genes osteocalcin (BGLAP) and osteoblast transcriptional factor (RUNX2). The comparison between DPS and Plus disks showed a slight induction of all the genes examined (RUNX2, ALPL, COL1A1, COL3A1, ENG, FOSL1, SPP1, and SP7); only the expression of BGLAP remained stable. The present study, demonstrated that implant surface topography affects osteoblast gene expression. Indeed, Plus surface produces an effect on MSCs in the late differentiation stages. [ABSTRACT FROM AUTHOR]

Abstract: This paper aims to establish a relationship between the surface morphology induced micromechanics and bone remodeling responses to a solid bead coated porous implant and further to develop a multiobjective optimization framework for the coating design of biomaterials. Multiscale modeling and remodeling techniques were developed, where a macroscopic analysis was initially performed to generate a global response to enable a microscopic analysis. The bone remodeling responses of the microscopic models (with a specific surface morphology) were evaluated in terms of the average apparent density developed in the peri-implant region. To explore the proposed multiscale analysis and design methods, a typical dental implantation setting is exemplified in this study. The response surface method (RSM) was utilized to relate the major implant coating parameters to the bone responses. It is found that increasing the volume fraction of the coating beads/particles results in a greater bone density, whereas increasing bead/particle size does not significantly affect the bone’s responses. Several different multiobjective optimization schemes were adopted to optimize the coated bead size and volume fraction, which reveal that the optimal design parameters of particle diameter and volume fraction are 100 μm – 35% and 38 μm – 17.5% for the cortical and cancellous bones respectively, agreeing with clinical data. To maximize the implant/bone interfacial stability, specific surface coating designs for particular locations are recommended. [Copyright &y& Elsevier]

Implant surface micro and macro topography plays a key role in early osseointegration. The physicochemical features of the implant surface (ie, chemical composition, hydrophobicity/hydrophilicity and roughness) influence the deposition of extracellular matrix proteins, the precipitation of bone mineral, and the stimulation of cells. Modification of the implant topography provides better primary stability and faster osseointegration, allowing for immediate placement or immediate loading. Randomized clinical trials are warranted to compare the response of osseointegration with various implant micro and macro surface topographies in people with various local or systemic risk factors., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The use of low-intensity pulsed ultrasound (LIPUS) is a promising approach to promote osteogenesis. However, few studies have reported the influence of this technique on the osseointegration of endosseous implants, especially regarding different implant topographies. We focused on how the initial interaction between cells and the titanium surface is enhanced by LIPUS and the potential regulatory mechanisms. The bone marrow mesenchymal stem cells (BMSCs) of rats were cultured on two types of titanium surfaces (polished surface, Flat and large grain blast acid etched, SLA) under LIPUS stimulation or control conditions. The cell proliferation on the implant surfaces was significantly promoted by LIPUS, which stimulated the increase in the number of microfilaments, pseudopodia formed and extracellular matrix mineralization nodules compared with those in the control group. The expression of osteogenesis-related genes, including OPN, OCN, BMP-2, ALP, Runx2 and Col-1, were up-regulated on all the surfaces by LIPUS stimulation. Our findings suggest that LIPUS enhances osteoblast differentiation from BMSCs on titanium surfaces. The use of LIPUS might be a potential adjuvant treatment to improve the osseointegration process., Competing Interests: None.