Short implants in the severely resorbed maxilla: A 2-year retrospective clinical study

Background: Although the predictability of endosseous dental implants is well documented, the restoration of the posterior region of the maxilla remains a challenge. The placement of short implants is one therapeutic option that reduces the need for augmentation therapy. Purpose: The purpose of this retrospective study was to assess the survival rates of 6 to 8.5 mm-long implants in the severely resorbed maxilla following a surgical protocol for optimized initial implant stability. Materials and Methods: The study included 85 patients with 96 short (6-8.5 mm) implants (Branemark System(R), Nobel Biocare AB, Goteborg, Sweden) supporting single-tooth and partial reconstructions. The implants had a machined (54) or an oxidized (TiUnite(TM), Nobel Biocare AB) (42) surface. A one-stage surgical protocol with delayed loading was used. The patients were followed for at least 2 years after loading (average follow-up period 37.6 months). The marginal bone resorption was assessed by radiographic readings. Results: Five implants were lost during the first 9 months, and four implants were lost to follow-up. The cumulative survival rate was 94.6%. Four of the failed implants had a machined surface, and one had an oxidized surface. The mean marginal bone resorption after 2 years in function was 0.44 +/- 0.52 mm. Conclusion: This study demonstrates that the use of short implants may be considered for prosthetic rehabilitation of the severely resorbed maxilla as an alternative to more complicated surgical techniques.