Underlying mechanisms at the bone‐surface interface during regeneration

Abstract

The goal of regenerative therapy around teeth and implants is to create a suitable environment in which the natural biological potential for functional regeneration of periodontal ligament and/or bone can be maximized. In order for the regenerative process to be successful, the following factors must be addressed: prevention of acute inflammation from bacteria, mechanical stability of the wound, creation and maintenance of blood clot-filled space, isolation of the regenerative space from undesirable competing tissue types, and the creation of a desirable surface chemistry, energy, roughness and microtopography that can directly influence cellular response, ultimately affecting the rate and quality of new tissue formation and, therefore, the regeneration process. This paper will review how surface characteristics (chemistry and roughness) can affect cell response and local factor production. To evaluate the effect of surface chemistry on cell proliferation and differentiation costochondral chondrocytes were grown on standard tissue culture plastic dishes sputter-coated with different materials. The results indicate that surface materials can elicit differential responses in cell metabolism and phenotypic expression in vitro. In a second study, the effect of varying titanium surface roughnesses on osteoblast-like cell behavior was examined. Surface roughness was found to alter osteoblast proliferation, differentiation and matrix production in vitro. In addition, production of PGE2 and TGF beta by these cells was also shown to increase with increasing surface roughness, indicating that substrate surface roughness also affects cytokine and growth factor production. The role of surface roughness in determining cellular response was further explored by comparing the response of osteoblasts grown on new and previously used surfaces. The results of these latter studies showed that cell proliferation, expression of differentiation markers and overall matrix production are not altered when cells are grown on used vs. virgin surfaces. This suggests the possibility that implants may be re-used, especially in the same patient, if they are appropriately treated. In this context, it should also be noted that rougher titanium surfaces may require more extensive cleaning procedures. From a global perspective, these studies provide some insight into how bone regeneration can be optimized in the presence of an implant or tooth root residing at the site of a bony defect. Since the new bone being produced, during regeneration, grows from a distal area toward the implant or tooth root surface, it is hypothesized that the osteoblasts growing on the surface of the implant may produce local factors that can affect the bone healing process distally. In short, it appears that the surface characteristics of an implant, particularly roughness, may direct tissue healing and, therefore, subsequent implant success in sites of regeneration by modulating osteoblast phenotypic expression.

In silicobiology of bone modelling and remodelling: regeneration

“…The principal mechanisms underlying the healing around implants are comparable to those of fracture healing (Schenk & Herrmann 1984;Gross 1988;Plenk & Zitter 1996;Overgaard 2000), although this view has triggered much debate since some authors have suggested that the presence of an implant induces a different healing mode (Schwartz et al 1997;Steflik et al 1998).…”

Implant Surface Design Regulates Mesenchymal Stem Cell Differentiation and Maturation

“…Surface roughness not only increases surface area but also affects cell morphology and increases osteoblastic differentiation, bone formation, and bone remodeling (Schwartz et al 1997;Wennerberg and Albrektsson 2009).osteoblastic differentiation and maturation (Olivares-Navarrete, Hyzy, Hutton, et al 2010) and implant osseointegration .…”

An investigation of reosseointegration according to time course after mechanical loosening of the osseointegrated implant fixtures

“…In contrast to Hwang et al, 3 the removal torque and BIC were significantly increased in 8 weeks of resettlement. It is considered that the implants with surface treatment support the continuous bone formation as the study of Schwartz et al, 11 which suggested that the rough surfaces of the implants with surface treatment stimulate proliferation and differentiation of osteoblasts to contribute preferable bone formation.…”