A retrospective 5-year follow-up study of two different titanium implant surfaces used after interpositional bone grafting for reconstruction of the atrophic edentulous maxilla.

BACKGROUND: Long-term comparative follow-up studies of dental implants placed in augmented bone are rare. Variations in design and surface roughness have been found to be important for bone integration of implants. However, there is no clinical evidence that such variations lead to an improved clinical outcome.

PURPOSE: To compare two different implant systems used after interpositional bone grafting of the severely resorbed maxilla with a modified augmentation technique using fibrin glue.

MATERIALS AND METHODS: Twenty-two consecutive patients presenting with severe maxillary atrophy underwent reconstruction with Le Fort I osteotomies and interpositional bone grafting. Before placement of bone blocks, the floors of the maxillary sinuses were packed with bone chips mixed with a fibrin glue, to stabilize the graft. After 6 months of graft healing, the first 11 consecutive patients received Brånemark System implants with a turned surface (Nobel Biocare AB, Göteborg, Sweden). The following 11 consecutive patients were treated with Astra Tech implants with a blasted titanium surface (Astra Tech AB, Mölndal, Sweden). All patients received fixed prostheses. Marginal bone resorption and donor and recipient site morbidity were evaluated. All patients were clinically and radiographically observed throughout 5 years of functional loading.

RESULTS: In the Brånemark group, 11 (13%) of 84 placed implants were lost, compared to 4 (5.5%) of 72 placed implants in the Astra Tech group. The difference was not significant. All patients retained fixed constructions after 5 years of loading. The mean marginal bone loss was 2.3+/-0.8 mm (range, 0-5.0 mm) in the Brånemark group and 2.4+/-1.4 mm (range, 0-7.0 mm) in the Astra Tech group although again no statistical difference was found. A larger number of implants in the Astra Tech group had a marginal bone resorption of>or=3 mm, and implant success in that group was lower than in the Brånemark group (52% vs 70%).

CONCLUSION: In this study, reconstruction of the severely resorbed maxilla with Le Fort I osteotomy, interpositional bone grafting, and delayed placement of dental implants was found to be a predictable long-term procedure. Although more implants with a turned surface were lost during the follow-up period, there were no statistically significant differences between turned and titanium blasted implants.