Purpose: The aim of this randomized, controlled, blinded clinical study was to compare ridge dimensions and histologic characteristics of ridges preserved with 2 different graft materials. Materials and Methods: Twenty-four subjects, each requiring a nonmolar extraction and delayed implant placement, were randomly selected to receive ridge preservation treatment with either an allograft in an experimental putty carrier plus a calcium sulfate barrier (PUT) or a bovine-derived xenograft (BDX) plus a collagen membrane. Horizontal and vertical ridge dimensions were determined using a digital caliper and a template. At 4 months postextraction, a trephine core was obtained for histologic analysis. Results: The average ridge width decreased by 0.50 mm for both groups (P .05). The midbuccal vertical change for the PUT group was a loss of 0.3 ± 0.7 mm versus a gain of 0.7 ± 1.2 mm for the BDX group, a difference of 1.0 mm (P > .05). Histologic analysis revealed vital bone in the PUT group of about 61% ± 9% versus 26% ± 20% for the BDX group (P .05). Discussion: Greater vital bone fill in the PUT group may be attributable to earlier and greater vascular invasion of the carrier material. The putty material was characterized by ease of handling, simple placement, and enhanced graft particle containment. Conclusions: Allograft mixed with an experimental putty carrier produced significantly more vital bone fill than did the use of a xenograft with no carrier material. Ridge width and height dimensions were similarly preserved with both graft materials.