RETRACTED: Bucco‐Lingual Crestal Bone Changes Around Implants Immediately Placed in Fresh Extraction Sockets in Association or not With Porcine Bone: A Non‐Blinded Randomized Controlled Trial in Humans (J Periodontol October 29, 2012 [published online ahead of print]; doi: 10.1902/jop.2012.120396). Issue 12 (1st December 2017) - Bottini, LP; Ricci, L; Piattelli, A; Perrotti, V; Iezzi, G