Preprosthetic periodontal surgery in the proximal area with modification of the COL area: results following the reestablishment of the contact point - Papalexiou, Vula; Novaes Júnior, Arthur Belém; Macedo, Guilherme O.; Luczyszyn, Sônia Mara; Muglia, Valdir Antônio (Journal of Periodontology, 2006)