Radiographic analysis of the transcrestal sinus floor elevation: short-term observations

There are some limitations for implant placement in the posterior maxilla when there is an extended sinus. Various techniques for sinus floor elevation allow an increase in implant length.

The aim of the present radiographic study was to assess the augmented site in the sinus around implants that were installed by means of an osteotome-mediated transcrestal sinus floor elevation.

Thirty-three patients with 44 implants were available. In 39% of the implants the sinus floor elevation was performed exclusively with bone chips. Bone fill material (Bio-Oss, Geistlich Söhne AG, Wolhusen, Switzerland) was additionally used to increase the volume and stability of the lifted area at 61% of the implants. The visibility and morphology of the augmentation were assessed and compared by means of intraoral radiography (long-cone technique).

All implants were stable and were considered to be successful when they were reexamined in the context of the present study. The mean residual bone height was 5.78 +/- 1.4 mm. The increase of the implant length as compared to the original bone height resulted in a mean value of 3.87 +/- 2.0 mm. The volume and density of the lifted area were more visible if Bio-Oss was added. A shrinkage and/or condensation of the grafted material was visible at 37% of the implants after a minimum loaded period of 200 days. Equally, a decreased visibility of the original sinus floor was noted at 61% of implants. The formation of a cortical bone layer at the apex of the implants was detected at 35% of implants.

The surgical procedure appears to be a safe method with rare complications. Radiographic assessment of the augmentation procedure proved to be difficult, and measurements are not fully reliable.