Graftless Full-Arch Implant Rehabilitation with Interantral Implants and Immediate or Delayed Loading-Part II: Transition from the Failing Maxillary Dentition

Purpose: To compare long-term survival and marginal bone loss of immediate interantral implants in the nonaugmented maxilla subjected to immediate vs delayed loading. Materials and Methods: Graftless maxillary cross-arch rehabilitation was performed in a total of 362 patients in the years 2004 to 2013 (1,797 implants). Of the 240 patients with immediate implants replacing their failing maxillary dentition, 81% were subjected to immediate loading and 19% to delayed loading of their 4 to 6 interantral implants (980 and 235 implants, respectively). Kaplan-Meier survival estimates were computed and marginal bone loss was evaluated in a stratified random sample of 20 patients per group. Results: Thirty-one of 1,215 implants failed within the mean observation period of 3.9 years, and no difference in 8-year survival estimates could be seen between immediate (97.6% [95% CI: 96.7 to 98.6]) and delayed (96.6% [95% CI: 94.3 to 98.9]) loading protocols (P=.359). Mean marginal bone resorption following implant insertion did not differ significantly between the groups (1.5 +/- 1.7 mm vs 0.7 +/- 1.1 mm, P=.379); however, it was significantly associated with a reduced number of implants (P=.017) and patient history of periodontal disease (P<.001). Conclusion: Immediate loading of interantral implants yields satisfactory results in the transition of patients from a failing maxillary dentition to full-arch implant rehabilitation and thus may be favored over delayed loading concepts.