This study presents the histomorphometric results of the Wafer Technique, which is based on guided bone regeneration and onlay grafts for 3D bone augmentation. This two-stage technique utilizes autogenous cortical bone plates and collagen membranes, forming a barrier containing a mixture of deproteinized bovine bone matrix, autologous blood, and bone grafted from intraoral sites. Twelve patients were treated. At 6 months postsurgery, histologic analysis of the regenerated areas revealed the presence of compact newly formed bone with no sign of inflammation. The percentages of new bone and native bone (mineralized tissue) were 16.4% (95% CI: 9.5% to 23.2%) and 42.6% (95% CI: 28.2% to 57.0%), respectively. Twenty-five implants were placed. The procedure has been proven to be safe and reliable, and only one transient complication was observed.