[1] Univ Hosp Regensburg, Dept Conservat Dent & Periodontol, Franz Josef Str Allee 11, D-93053 Regensburg, Germany
[2] Univ Regensburg, Univ Lib, Regensburg, Germany
[3] Katholieke Univ Leuven, BIOMAT Biomat Res Grp, Dept Oral Hlth Sci, Leuven, Belgium
[4] Univ Hosp Leuven, Dent, Leuven, Belgium
[5] Univ Int Catalunya, Fac Dent, Dept Endodont, Barcelona, Spain