title: The bone-implant interface of dental implants in humans on the atomic scale.
abstract: Osseointegration of dental implants occurs on a hierarchy of length scales down to the atomic level. A deeper understanding of the complex processes that take place at the surface of an implant on the smallest scale is of interest for the development of improved biomaterials. To date, transmission electron microscopy (TEM) has been utilized for examination of the bone-implant interface, providing details on the nanometer level. In this study we show that TEM imaging can be complemented with atom probe tomography (APT) to reveal the chemical composition of a Ti-based dental implant in a human jaw on the atomic level of resolution. As the atom probe technique has equal sensitivity for all elements, it allows for 3 dimensional characterizations of osseointegrated interfaces with unprecedented resolution. The APT reconstructions reveal a Ca-enriched zone in the immediate vicinity of the implant surface. A surface oxide of some 5nm thickness was measured on the titanium implant, with a sub-stoichiometric composition with respect to TiO2. Minor incorporation of Ca into the thin oxide film was also evident. We conclude that the APT technique is capable of revealing chemical information from the bone-implant interface in 3D with unprecedented resolution, thus providing important insights into the mechanisms behind osseointegration.
  
  
  
  Osseointegration of dental implants occurs on a hierarchy of length scales down to the atomic level. A deeper understanding of the complex processes that take place at the surface of an implant on the smallest scale is of interest for the development of improved biomaterials. To date, transmission electron microscopy (TEM) has been utilized for examination of the bone-implant interface, providing details on the nanometer level. In this study we show that TEM imaging can be complemented with atom probe tomography (APT) to reveal the chemical composition of a Ti-based dental implant in a human jaw on the atomic level of resolution. Correlative microscopy ensures the accuracy of APT reconstructions and helps provide both chemical and structural information of the bone-implant interface on the smallest of length scales.
authors.affiliation: Department of Applied Physics, Chalmers University of Technology, SE-41296 Gothenburg, Sweden. Electronic address: gustav.sundell@chalmers.se.
authors.forename: Gustav
authors.initials: G
authors.lastname: Sundell
authors.affiliation: Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg and the BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, SE-40530 Gothenburg, Sweden; Department of Oral & Maxillofacial Surgery, NU-hospital Organization, SE-461 73 Trollhättan, Sweden.
authors.forename: Christer
authors.initials: C
authors.lastname: Dahlin
authors.affiliation: Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-41296 Gothenburg, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Andersson
authors.affiliation: Department of Applied Physics, Chalmers University of Technology, SE-41296 Gothenburg, Sweden.
authors.forename: Mattias
authors.initials: M
authors.lastname: Thuvander
mesh_terms: D000069343:Bone-Implant Interface; D015921:Dental Implants; D006801:Humans; D021621:Imaging, Three-Dimensional; D013058:Mass Spectrometry; D010087:Oxides / Q000737:chemistry; D014054:Tomography
chemical_list: D015921:Dental Implants; D010087:Oxides
keywords: Atom probe tomography; Dental implant; Osseointegration; Titanium implant; Transmission electron microscopy