Retraction.

Negri B, Calvo-Guirado JL, Pardo-Zamora G, Ramírez-Fernández MP, Delgado-Ruíz RA, Muñoz-Guzón F. Peri-implant bone reactions to immediate implants placed at different levels in relation to crestal bone. Part I: a pilot study in dogs. Clin Oral Impl Res. 2012;23: 228-235. The above article, published online on 24 March 2011 in Wiley Online Library (wileyonlinelibrary.com) and in Volume 23, pp. 228-235, has been retracted by agreement between the journal Editor in Chief, L Heitz-Mayfield, and John Wiley & Sons Ltd. The retraction has been agreed due to image discrepancies, resulting in unreliable data. Images in Figure 6a have been used in another publication representing different time points. Reference Negri B, Calvo-Guirado JL, Pardo-Zamora G, Ramírez-Fernández MP, Delgado-Ruíz RA, Muñoz-Guzón F. Peri-implant bone reactions to immediate implants placed at different levels in relation to crestal bone. Part I: a pilot study in dogs. Clin Oral Impl Res. 2012;23: 228-235. https://doi.org/10.1111/j.1600-0501.2011.02158.x.