Microstructured zirconia surfaces modulate osteogenic marker genes in human primary osteoblasts.

Claudia Bergemann,Hermann Seitz,Jens Fischer,Kathrin Duske,J Barbara Nebe,Ulrike Bulnheim,André Schöne

doi:10.1007/s10856-014-5350-x

Abstract

In dentistry, zirconia has been used since the early 1990s for endodontic posts, more recently for implant abutments and frameworks for fixed dental prostheses. Zirconia is biocompatible and mechanically strong enough to serve as implant material for oral implants. Although several zirconia implant systems are available, currently the scientific and clinical data for zirconia implants are not sufficient to recommend them for routine clinical use. Here the influence of microstructured yttria-stabilized zirconia (YZ) on human primary osteoblast (HOB) behavior was determined. YZ surfaces were treated by sandblasting (YZ-S), acid etching (YZ-SE) and additionally heat treatment (YZ-SEH). Morphological changes of HOB were determined by scanning electron microscopy. Actin cytoskeleton was investigated by laser scanning microscopy and analyzed by novel actin quantification software. Differentiation of HOB was determined by real time RT-PCR. Improved mechanical interlocking of primary HOB into the porous microstructure of the acid etched and additionally heat treated YZ-surfaces correlates with drastically increased osteocalcin (OCN) gene expression. In particular, OCN was considerably elevated in primary HOB after 3 days on YZ-SE (13-fold) as well as YZ-SEH (12-fold) surfaces. Shorter actin filaments without any favored orientation on YZ-SE and YZ-SEH surfaces are associated with higher roughness (Ra) values. Topographically modified yttria-stabilized zirconia is a likely material for dental implants with cell stimulating properties achieving or actually exceeding those of titanium.

Highlights

The objective of oral implantology is to replace lost natural teeth with artificial, designed implants with the purpose of providing additional masticatory units
Scanning electron microscopy attested the increasing surface roughness of yttria-stabilized zirconia (YZ) according to the treatments used (Fig. 1)
We focused on the response of primary human osteoblasts on yttria-stabilized zirconia surfaces with a microstructure created by etching after sand blasting

Summary

Introduction

The objective of oral implantology is to replace lost natural teeth with artificial, designed implants with the purpose of providing additional masticatory units. The benefits of implants are (i) to avoid grinding of intact, adjacent teeth, which is unavoidable when constructing a fixed dental prosthesis, (ii) to avoid a removable partial denture by providing an abutment for a fixed restoration, or (iii) to stabilize a removable dental prosthesis. Titanium implants are state of the art. It is a generally and worldwide-accepted doctrine that the endosseous part consists of a screw to afford primary stability and a rough surface to guarantee the successful osseointegration. The part penetrating the mucosa has to have a polished surface to impede bacterial adhesion. These facts are undisputed and well established in the relevant textbooks [1].

Methods

Results

Discussion

Conclusion