SIMS of biomineralized tissues: present trends and potentials

Physics Department, Chalmers University of Technology, Gothenburg, Sweden.

The technique of dynamic secondary ion mass spectrometry (SIMS) has, during the 1980s, become a firmly established tool in the microanalytical and microstructural characterization of dental hard tissues. SIMS has proved to be outstandingly suited for charting the distributions of most elements, even at extremely low concentrations, in tooth and bone materials. In-depth concentration profiles as well as surface distribution maps of elements have been recorded with excellent (sub-micron) morphologic resolution. In spite of documented success, only relatively few teams, in a handful of countries, are presently engaged, to any significant extent, in conducting tooth or bone research by the application of SIMS. For dental-medical-surgical laboratories, a partial reason for non-communication is a lack of information about SIMS and its particular assets. Another reason may be connected with an essentially groundless reputation, among non-specialists, of SIMS being an exclusive and expensive technique. Among SIMS laboratories, on the other hand, the inertia in tackling biomineralization is partly due to some particular artifacts of analysis, hitherto not generally known and controlled. The present paper briefly sketches the chief principles of modern SIMS, emphasizing factors of special relevance in the characterization of biomineralized tissues. Examples of recent applications are provided. Present procedures and their limitations are discussed, especially with regard to elemental quantification and imaging. Suggestions for relatively simple modifications to existing routines are offered with the aim of enhancing the ease and availability of SIMS in odontological and surgical research.