The aim of this study was to examine the formation and density of new bone around dental implants inserted simultaneously after grafted versus non-grafted maxillary sinus floor augmentation and to correlate secondary implant stability to bone density. Twenty patients requiring the placement of implants in the posterior maxilla with deficient bone height were recruited for the study. Patients were randomly assigned to either group. The formation and density of new bone were evaluated using Cone-Beam Computed Tomography, performed postoperatively and after 6 months. Pearson coefficient was used to correlate bone density and secondary implant stability in both groups. All implants achieved adequate primary stability and were successfully loaded. Both groups showed comparable secondary stability with a mean of (77.9 ± 3.9) for the grafted and (74.8 ± 5.6) for the non-grafted group. Bone density values were (973.6 ±142.5) and (443.7 ± 97.8), and bone height gain was (6.6 ± 0.5) and (6 ± 0.5) for the grafted and the non-grafted groups respectively, with the grafted group showing significantly higher values. Secondary stability showed a significant positive linear correlation with bone density in the grafted group (r = 0.549 at p ≤ 0.05). In conclusion, Sinus floor elevation with and without grafting is considered an acceptable and successful procedure with simultaneous implant placement. Furthermore, higher density values in the grafted sinuses resulted in higher secondary stability.