RETRACTED: A Practice-Based Case Series Evaluation of a Porcine Collagen Matrix to Thicken Soft Tissue, Increase Keratinized Tissue, and Improve Esthetics Around Existing Dental Implants (Clin Adv Periodontics March 28, 2012 [published online ahead of print]; doi: 10.1902/cap.2012.110077)

Retraction: The following article from Clinical Advances in Periodontics, “A Practice-Based Case Series Evaluation of a Porcine CollagenMatrix to Thicken Soft Tissue, Increase Keratinized Tissue, and Improve Esthetics Around Existing Dental Implants” by Schallhorn et al., published online ahead of print onMarch 28, 2012, has been retracted by the journal Co-Editors, Drs. Kenneth S. Kornman andMichael S. Reddy. The retraction occurred following online publication after it was determined by the Co-Editors, upon closer review, this case series qualifies as research and therefore requires institutional review board (IRB) approval. According to Clinical Advances in Periodontics guidelines, a case series is classified as “research” if investigators ask a specific question and collect and analyze data to answer that question, even when the cases are treated as part of routine clinical management and FDA-cleared devices or drugs are used. Following communications among the Co-Editors, authors, and editorial staff, it was confirmed that the authors were unable to obtain IRB approval or an exemption; therefore, the article was retracted. n