Comparison of the Crestal Bone Loss Between Implant-Supported Prosthesis With Sinus Augmentation and Distal Cantilevered Implant-Supported Prosthesis Without Sinus Augmentation.

This study aimed to compare the crestal bone loss between a 2-implant-supported, noncantilevered 3-unit fixed partial prosthesis (TUFPP) with sinus augmentation and a 2-implant-supported, distal cantilevered TUFPP without sinus augmentation in the posterior maxilla having insufficient crestal bone. The study subjects were enrolled in 2 groups. Group 1 included patients with 2 implants: an anterior implant placed in the native bone and a posterior implant inserted with simultaneous sinus augmentation using a xenogenic bone graft to support a TUFPP. Group 2 included patients with 2 implants inserted in the native bone to support a distal cantilevered TUFPP. The crestal bone levels at the distal and mesial aspects of each implant were measured at baseline and 6-, 12-, and 24-month follow-up controls on panoramic radiographs. Fifty-two patients and 104 implants were included. There was a significant difference in distal crestal bone loss between anterior and posterior implants in group 1 at 6 months (P < .05) but not at 12 and 24 months (P > .05). Distal crestal bone loss was significantly increased in group 1 posterior implants compared to the group 2 posterior implants at 6 months (P < .05). There was no significant difference in mesial bone loss between the anterior and posterior implants in both groups at all follow-up controls (P > .05). There was also no significant mesial crestal bone loss in relation to the anterior and posterior implants of both groups at all follow-up controls (P > .05). Noncantilevered 2-implant-supported TUFPP with sinus augmentation may have similar medium-term crestal bone loss when compared to cantilevered 2-implant-supported TUFPP without sinus augmentation. Further prospective studies should be designed to compare the performance of the 2-implant-supported cantilevered TUFPP and 2-implant-supported TUFPP with sinus augmentation.