Root trunk concavities as a risk factor for regenerative procedures of class II furcation lesions in humans - Villaça, José Henrique; Rodrigues, Débora Cristina; Novaes Júnior, Arthur Belém; Taba Júnior, Mário; Souza, Sérgio Luis Scombatti de; Grisi, Márcio Fernando de Moraes (Journal Periodontology, 2004)