Short, parallel-walled, conical-connection implants for a broad range of indications in the maxilla and mandible: Retrospective multicenter study with up to 33 months of follow-up

Objective: To evaluate the survival and complication rate of 7-mm short, parallel-walled, conical-connection implants in daily practice. Method and Materials: This multicenter retrospective study included 219 consecutive patients who received 323 implants. Indication was limited vertical bone height preventing placement of implants longer than 7 mm. Placement and loading protocols were determined on a case-by-case basis and included placement in fresh extraction sockets and healed sites, and loading was either immediate, early, or delayed. Patients were followed for up to 33 months. Outcome measures were implant survival rate and any biologic or technical complications. Results: In total, eight implants in seven patients failed, accounting for the survival rate of 97.3% at implant level and 96.4% at patient level. The mean time to failure was 7.5 months and 10.2 months at the implant and patient level, respectively. The majority of patients (67.1%) received one implant and the placement was predominantly in healed sites (82.7%). Immediate loading was done for 21.4% of implants placed in the extraction site and for 21.3% of implants placed in healed sites. In most of the cases (71.8%) implants were placed in the premolar or molar position in the mandible. No complications were reported. Conclusion: These results suggest that in cases of limited vertical bone height, the short, parallel-walled, conical-connection implant can successfully support different prosthesis types in a wide variety of indications and loading protocols. Keywords: conical connection, multicenter, parallel-walled, retrospective, short implant