Search

Regulation of cellular function is key to bone formation at endosseous implant surfaces. Osseointegration was "discovered" prior to the discovery of genetic regulation of osteoinduction or characterization of mesenchymal stem cells. Understanding osseointegration in cellular and molecular terms has benefited from genome-wide characterization of this healing process at endosseous implants in vivo. These in vivo studies also demonstrate a role for osteoprogenitor cells and cells involved in immune regulation and osteoclastogenesis. The identification of noncoding RNAs, including microRNAs, as key factors controlling cell function has highlighted the role of microRNAs in cell differentiation control. This review summarizes emerging in vitro and in vivo investigations emphasizing the role of microRNAs in the osseointegration process. Many microRNAs influence key osteoinductive pathways controlling Osterix, runt-related transcription factor 2 (RUNX2), and bone morphogenetic protein (BMP)/SMAD function. Others influence the monocyte/ macrophage lineage. While significant progress has been made in elucidating the mechanisms associated with the regulation of surface modulation of osteoblast differentiation by microRNAs, knowledge gaps are evident in the identification and characterization of microRNAs linked to osseointegration. Given existing knowledge regarding the varied expression of microRNAs and their role in inflammation, it is important to understand how microRNA expression may influence the process of bone accrual at implant surfaces during osseointegration. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate commercially pure titanium implant surfaces modified by laser beam (LS) and LS associated with sodium silicate (SS) deposition, and compare them with machined surface (MS) and dual acid-etching surfaces (AS) modified. Topographic characterization was performed by scanning electron microscopy-X-ray energy dispersive spectroscopy (SEM-EDX), and by mean roughness measurement before surgery. Thirty rabbits received 60 implants in their right and left tibias. One implant of each surface in each tibia. The implants were removed by reverse torque for vivo biomechanical analysis at 30, 60, and 90 days postoperative. In addition, the surface of the implants removed at 30 days postoperative was analyzed by SEM-EDX. The topographic characterization showed differences between the analyzed surfaces, and the mean roughness values of LS and SS were statistically higher than AS and MS. At 30 days, values removal torque LS and SS groups showed a statistically significant difference ( p < 0.05) when compared with MS and AS. At 60 days, groups LS and SS showed statistically significant difference ( p < 0.05) when compared with MS. At 90 days, only group SS presented statistically higher ( p < 0.05) in comparison with MS. The authors can conclude that physical chemistry properties and topographical of LS and SS implants increases bone-implant interaction and provides higher degree of osseointegration when compared with MS and AS. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 101B: 76-84, 2013. [ABSTRACT FROM AUTHOR]