Rehabilitation of the Atrophic Edentulous Maxilla: A Retrospective Cohort Study Comparing Survival of Delayed-Loaded Implants in Grafted Bone Versus Immediately Loaded Implants in Native Bone

Abstract

Objectives: This retrospective cohort study aimed to assess the survival rate of implants placed in grafted edentulous maxillary arches following a delayed loading protocol versus a graftless approach with an immediate loading protocol. Materials and Methods: Eighty seven patients with atrophic edentulous maxillae were included in two groups: Group-1 (GG group, n = 155 implants): 26 patients that underwent maxillary bone grafting before treatment with axially placed delayed loading implants and provided with a fixed full-arch prostheses; Group-2 (GL group; n = 244 implants): 61 patients who received axial and tilted implants without bone augmentation followed by an immediately loaded fixed full-arch prostheses. Patients were followed up for up to 10 years. Kaplan–Meier and Mantel–Cox analyses were performed to determine implant survival rates, and a Cox hazards model was run to assess the influence of patient, implant, and prosthesis-based covariates. Results: There were no significant differences in implant failure rates between the two treatment groups (p = 0.298). Five implant failures were observed in Group-1 (GG group) and four failures were observed in Group-2 (GL group) (N = 9). Survival rate was 96.8% and 98.4% in the GG and GL groups, respectively. No significant association between patient and implant-based covariates and implant failure was observed in both groups; however, a significant association was observed regarding the nature of the opposing arch (p = 0.019). Conclusion: Immediately loaded implants placed in maxillary native bone show statistically similar survival rates compared to implants placed in grafted bone following a delayed loading. The nature of the opposing arch may negatively influence the survival rate of dental implants. Clinical Significance: For atrophic edentulous maxillae, both grafted and graftless approach may represent a viable treatment modality in the long term.