Comparison of two surgical techniques for root coverage with a porcine collagen matrix: a randomized controlled clinical trial with 6 months of follow up - Novaes Júnior, Arthur Belém; Reino, D. M.; Muglia, Valdir Antônio; Maia, L. P.; Fernandes, P. G. (International Association for Dental Research General Session-IADR, 2015)