© 2014 American Academy of Periodontology. Background: The purpose of this multicenter randomly controlled clinical trial was to compare two acellular dermal matrix (ADM) materials produced by different processing techniques, freeze-dried (FDADM) and solvent-dehydrated (SDADM) ADM, in their ability to correct Miller Class I and II recession defects.Methods: Eighty individuals from four study centers, each with a single maxillary anterior Miller Class I or II recession defect were enrolled. Participants were randomly assigned and treated with coronally advanced flap (CAF) + FDADM (n = 42) or CAF + SDADM (n = 38). Gingival thickness, recession depth, recession width, probing depth (PD), clinical attachment level, gingival index, plaque index, patient discomfort, and wound healing index were recorded before surgery (day 0), immediately after surgery (day 1), and 2, 4, 12, 24, and 52 weeks postoperatively. The Student t test, paired t test, and Kruskal-Wallis one-way ANOVA were used to analyze the data.Results: When evaluating the clinical parameters after 1 year, both groups showed significant (P <0.05) improvement for most of the parameters evaluated when compared to baseline (day 0). For example, percentage of root coverage was 77.21% ± 29.10% for CAF + FDADM and 71.01% ± 32.87% for CAF + SDADM. Conversely, no significant differences were observed between the two materials for any clinical parameter tested or for patient satisfaction except PD on the mesial side of the defects (P = 0.03).Conclusions: Both FDADM and SDADM can be used successfully to correct Miller Class I or II recession defects. There were no statistically significant differences between groups for any of the clinical parameters tested.