A histologic assay of the grafting material associated with the sinus elevation procedure would provide insight into the quality and quantity of vital bone at the implant-bone interface. This case report documented for the first time the sequential healing process of a sinus graft in the same patient at 4, 8, 12, and 20 months. Histology of trephine-obtained core samples showed that in a sinus grafted with a mixture of xenograft (80%) and autograft (20%), 12 to 20 months was required for remodeling to vital bone. The study also demonstrated that a significant amount of vital, mature bone was generated by this procedure. Quantification of the resulting bone and comparison with other grafting techniques should be the next phase of continuing research efforts.