The bone-implant interface – nanoscale analysis of clinically retrieved dental implants

• Published in: Nanomedicine Vol. 10; no. 8; pp. 1729 - 1737
• Main Authors: Shah, Furqan Ali, Nilson, Bengt, Brånemark, Rickard, Thomsen, Peter, Palmquist, Anders
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2014
• Subjects: Aged; Bone bonding; Coated Materials, Biocompatible; Dental implant; Dental Implants; Electron microscopy; Female; Humans; Internal Medicine; Nano; Odontologi; Odontology; Osseointegration; Prostheses and Implants; Structure-Activity Relationship; Titanium; Ultrastructure; Nano; Bone bonding; Osseointegration; Electron microscopy; Ultrastructure; Dental implant
• ISSN: 1549-9634; 1549-9642; 1549-9642
• DOI: 10.1016/j.nano.2014.05.015

Evaluation of the fine structure of the bone-implant interface in humans is a prerequisite for a deepened understanding of structure–function relationships with nano-modified biomaterials. In this study, three clinically stable, yet retrieved, laser-modified dental implants were evaluated using histological and interface ultrastructural analyses. The cumulative results for all threads containing intact tissue showed remodeled Haversian bone with bone area and bone-implant contact in excess of 85% and 80%, respectively. Collagen fibrils, laid down parallel to the surface oxide layer, were mineralized by plate-like crystallites of stoichiometrically relevant (Ca/P ratios 1.30-1.67) bone-apatite. An overlap of titanium, oxygen, calcium and phosphorus signals indicated the gradual intermixing of bone-apatite and the nano-rough surface oxide. These results suggest that bone bonding to nano-textured titanium implant surfaces is promoted in human jaw-bone after functional loading. In this study, newly developed and laser-modified titanium dental implants demonstrate strong evidence for implant-osseo integration basen on the surface and chemical analysis of three clinically stable dental implants. In-depth analysis of bone tissue interfacing nanostructured implants retrieved from a human subject after 47months in vivo revealed a hierarchical organization and nano-osseointegration. Bone formed within the implant threads is arranged in a concentric lamellar pattern and osteocytes are found close to the surface with canaliculi extending toward the surface oxide. Transmission electron microscopy shows a functionally graded interface with mineralized collagen fibrils laid parallel to the implant surface and bone apatite penetrating into the nanoscale irregularities of the surface oxide layer. [Display omitted]