Graftless sinus floor augmentation with an internal-port implant: long-term experience

Objective: The objective was to assess the outcome of graftless sinus floor augmentation associated with dental implant placement performed with an implant system that has an internal port and screw, combined with the osteotome technique. Method and materials: Between 2012 and 2018, 722 titanium-aluminum-vanadium implants (Ti-6Al-4V ELI, diameter 3.75/4.20 mm) were placed in 331 patients. Implants 11.5 mm in length were inserted in maxillae with bone level ≤ 5 mm, and 13.0-mm-long implants were inserted in maxillae with bone level of > 5 to 8 mm. In all cases, no graft materials or bone substitutes were used for the sinus elevation. Implant condition was assessed at three different centers and the follow-up period ranged from 6 months to 7 years. Results: In total, 412 11.5-mm-long implants and 310 13-mm-long implants were inserted. Implantation was successful in 689 implants (95.4%), based on cone beam computed tomography and clinical evaluation as well as the patients' experience, with no statistically significant difference between the 11.5-mm and 13.0-mm implants. The complication rates were comparable between cases with bone levels from 3 to 5 mm and the > 5- to 8-mm bone level cases. Conclusions: The port and screw implant system may allow maxillary sinus augmentation without grafting or bony substitute. This can simplify relatively major surgery, such as a sinus augmentation procedure, to a less invasive procedure and potentially reduce the risk of complications. Keywords: dental implant, graft, implant maintenance, maxillary sinus floor elevation