Purpose: To investigate and analyze the effects of different prosthetic protocols under different loading and occlusal conditions on the survival rates of single implants immediately placed into fresh extraction sockets of maxillary or mandibular premolars with single-stage surgery.
Materials and Methods: Patients needing replacement of a single premolar in the maxilla or mandible were included and randomly divided into three groups based on the different loading protocols: group 1 = healing abutment; group 2 = provisional crown left out of occlusion without functional loading; and group 3 = provisional crown in functional occlusion in maximum intercuspation without contact in excursions. The hypothesis was that single implants inserted into fresh extraction sockets and immediately connected to a temporary crown under functional loading would demonstrate survival rates comparable to single implants placed in the same conditions connected to a healing abutment or to an immediate temporary crown left out of occlusion.
Results: A total of 112 patients were treated, and 126 implants were placed (92 in the maxilla and 34 in the mandible). After a mean follow-up of 2.5 years (range 1 to 5 years), there were no failures in groups 1 or 2. Two implants failed in group 3 (one in the maxilla, one in the mandible). The cumulative survival rate was 98.5% across all groups, with 100% in groups 1 and 2 and 95% in group 3. Statistical analysis showed that group 3 displayed a survival rate comparable to groups 1 and 2 (P = .08).
Conclusion: Within the limitations of this study, no significant differences were found in terms of implant survival rates between implants inserted into fresh extraction sockets without loading vs with immediate nonfunctional or functional loading.