680 RaSDA: 3D-assessment of Tooth Movements Based on Master-casts

Friday, March 23, 2012: 8 a.m. - 9:30 a.m.
Presentation Type: Oral Session
R.G. LUTHARDT1, R. DING1, S. WOLFART2, W. HANNAK3, H. STARK4, N. PASSIA5, B. WÖSTMANN6, T. MUNDT7, G. HEYDECKE8, F. JAHN9, M. KERN10, P. POSPIECH11, L. BIRKNER12, S. HARTMANN13, J. GÜTH14, E. BUSCHE15, J. HUPPERTZ16, B. MARRÉ17, A. WEBER17, K. BOENING17, M. WALTER17, and H. RUDOLPH1, 1Center of Dentistry, Department of Prosthetic Dentistry, University Ulm, Ulm, Germany, 2Medical Faculty, RWTH Aachen University, Aachen, Germany, 3Prosthodontics, Charité, Berlin, Germany, 4Poliklinik fur Zuhnarztliche Prothetik, Zentrum fur Zahn-Mund und Kieferheikunde der Universitat, Bonn, Germany, 5Poliklinik für Zahnärztliche Prothetik, Universitätsklinikum Freiburg, Freiburg, Germany, 6Prosthodontics, Justus-Liebig-University Giessen, Giessen, Germany, 7Prosthodontics, University of Greifswald, Greifswald, Germany, 8Prosthodontics, Universitätsklinikum Eppendorf, Hamburg, Germany, 9Prosthodontics, Universitätsklinikum Jena, Jena, Germany, 10Dept of Prosthodontics, Christian-Albrechts University, Kiel, Germany, 11Prosthodontics, University of Krems, Krems, Austria, 12Poliklinik für Zahnärztliche Prothetik, Friedrich-Louis-Hesse-Zentrum für Zahn-, Mund- und Kieferheilkunde und Orale Medizin, Leipzig, Germany, 13University Mainz, Mainz, Germany, 14Poliklinik für Zahnärztliche Prothetik, Klinikum der Ludwig-Maximilian-Universität München, München, Germany, 15Prosthodontics, Universität Witten-Herdecke, Witten-Herdecke, Germany, 16Prosthodontics, Universitätsklinikum Würzburg, Würzburg, Germany, 17Poliklinik fur Zahnärztliche Prothetik, University of Dresden, Dresden, Germany

The multi-center randomized shortened dental arch study (RaSDA) intended to compare the two different treatment options for bilaterally shortened dental arch cases. Patients received either a precision attachment retained removable dental prosthesis (RDP) for molar replacement or were treated following the shortened dental arch (SDA) concept without molar replacement. Aim of the present analysis was to evaluate tooth movements and changes in tooth morphology.


10 randomly selected cases, five each of the RPD and the SDA group, were analyzed. Inclusion criterion for this analysis was the presence of complete sets of master-casts in sufficient quality (baseline, 3-Year follow-up, 5-Year follow-up). First, the master-casts were inspected visually. Second, the master-casts were digitized (digiSCAN L, Amann Girrbach, Pforzheim, Germany) and CAD surface models created (Surfacer 10.6, Imageware Inc., Ann Arbor, Michigan, USA; geomagic studio 9.0, Geomagic Inc., Research Triangle, NC, USA). Data of the baseline master-cast were used as reference while 3-year and 5-year data was superimposed to the reference. Differences were analyzed three-dimensionally (3D) over time regarding movements of teeth and variations of tooth morphology.


Using the 3D-analysis of master-casts, 3 cases showed movements of teeth and 9 cases showed wear compared with baseline. While applying visual inspection, tooth movements were recognized precisely, the computerized analysis using digitizing, alignment and 3D-measurments showed superior results in the detection of wear.


Precise 3D-analysis of digital data acquired from master-casts produced at different points in time is challenging regarding the rigorous alignment requirements for data sets being in different measurement coordinate systems into a conjoint coordinate system applicable for data analysis. Using the 3D-analysis, movement of teeth and wear can be assessed precisely over time. However, the procedure is based on specific hard- and software and is time-consuming.

This abstract is based on research that was funded entirely or partially by an outside source: Founded by the Deutsche Forschungsgemeinschaft (DFG)

Keywords: Clinical trials, Prosthodontics and Wear
See more of: Digital Dentistry
See more of: Prosthodontics Research