Effect of sputter-coating on cracking of root-end surfaces after ultrasonic retrograde preparation: a sem study of resected root apices and their respective impressions - Bramante, Clóvis Monteiro; Moraes, Ivaldo Gomes de; Bernardineli, Norberti; Garcia, Roberto Brandão; Pidero, Cláudio Urra; Ordinola-Zapata, Ronald; Bramante, Alexandre Silva (Acta Odontologica Latinoamericana, 2010)