Localised maxillary sinus lift, approached via the ridge, prior to placing implants

Aim of the study

The absence of sufficient bone under the maxillary sinus has led many authors to develop and test surgical techniques aimed at raising the sinus floor to enable implants to be fitted. This article presents a technique of localized sinus floor lift (LSL) with a ridge approach in cases where the volume of bone is sufficient to ensure primary stabilisation of the implant.

Materials and methods

Ninety-seven implants (25 cylindrical and 72 screwed) were placed according to the LSL technique. After 6 months osseointegration they were brought into function with provisional resin restorations which, after 6-9 months, were replaced with definitive prostheses. Standardised long cone superimposable radiographs were taken at different stages of treatment. The LSL technique was performed in four stages : preparation of the bony bed via the ridge, fracture of the sinus floor, elevation of the sinus membrane using a collagen sponge and bone chippings recovered from the drilling procedure and placement of the implant.

Conclusion

In all cases, healing occurred uneventfully with no pathological reaction of the sinus. The elevation of the sinus floor varied from 1 to 6 mm (mean = 2.9 mm). Analysis of the 11 failures (eight implants failed to osseointegrate and three were lost after being brought into function) demonstrate the limitations of the technique : minimal drilling in Type IV bone, primary stability is unlikely if the height of bone is less than 5 mm, risk of tearing the membrane in the case of elevations greater than 5 mm, avoidance of removable appliances over implants during healing and the avoidance of implants of less than 10 mm.

Commentary

The LSL technique is achievable in the surgery and is very well explained stage by stage by the authors, with the aid of diagrams, radiographs and photographs. It is comparable to the technique described by Summers in 1994, with an interesting debate on differences in the protocol. The failures are well analysed and clinical recommendations deduced. Here is a fascinating article describing a technique that one is impatient to put into practice.