Leirião, F.P. et al. 2003. Histological study of the periodontal structures, comparing gingival displacement by use of copper band and by cotton string, in dogs. Brazilian Journal of Veterinary Research and Animal Science. 40, 5 (Jan. 2003), 382–388. DOI:https://doi.org/10.1590/S1413-95962003000500010.