[1] Case Sch Dent Med, Cleveland, OH USA
[2] Univ Maryland Baltimore, Sch Dent, Dept Adv Oral Sci & Therapeut, Div Endodont, Baltimore, MD USA
[3] Centreville Endodont, Centreville, VA USA
[4] Univ Sharjah, Coll Dent Med, Dept Prevent & Restorat Dent, Sharjah, U Arab Emirates
[5] ITU WHO Focus Grp Hlth, Top Grp Dent Diagnost & Digital Dent, Berlin, Germany
[6] Univ Penn, Sch Dent Med, Dept Endodont, Philadelphia, PA USA
[7] Case Sch Dent Med, Dept Endodont, Cleveland, OH 44106 USA