[1] Oregon Hlth & Sci Univ, Sch Dent, Dept Restorat Dent, Portland, OR 97201 USA
[2] Oregon Hlth & Sci Univ, Div Biomat & Biomech, Portland, OR 97201 USA
[3] Univ Colorado, Sch Dent Med, Dept Craniofacial Biol, Anschutz Med Campus, Boulder, CO 80309 USA
[4] Univ Colorado, Dept Chem & Biol Engn, Boulder, CO 80309 USA
[5] Univ Manchester, Sch Med Sci, Div Dent, Manchester, Lancs, England
[6] Univ Manchester, Photon Sci Inst, Manchester, Lancs, England
[7] Ludwig Maximilians Univ Munchen, Univ Hosp, Dep Operat Dent & Periodontol, Goethestr, Munich, Germany
[8] Ivoclar Vivadent AG, Res & Dev, Schaan, Liechtenstein
[9] Univ Trieste, Dept Med Sci, Trieste, Italy