Enxerto total de maxila com 100% de bio oss : estudo retrospectivo clínico e tomográfico

Abstract

Background: Tooth loss and the use of a complete denture for years is still a reality and results in bone loss. Adequate reconstruction of an extremely atrophic edentulous maxilla is a challenge, and different treatment methods have been described for its resolution. The objective of this study was: a) to describe a technique using 100% deproteinized bovine bone matrix (DBBM) for maxilla reconstruction, b) to measure horizontal bone gain 6 to 8 months after bone graft in the anterior region of the maxilla, and c) to evaluate the survival rate and variables related to bone augmentation and/or implant survival rate. Methods: Patients (18 to 85 years old) seeking implant placement in edentulous upper jaw with an atrophic maxilla were selected in a private clinic in the city of Porto Alegre, Brazil. The bone graft was performed with a bilateral sinus lift and a horizontal bone graft in the anterior region, both with 0,25-1mm particles of DBBM (Bio-Oss, Geistlich, Switzerland) covered with a collagen membrane (Bio-Gide, Geistlich). Cone beam computed tomography (CBCT) were evaluated to verify the need for bone graft, and after 6-8 months bone graft follow-up, to plan the implant placement and to assess the horizontal bone gain. Results: A total of 124 implants were placed in 19 patients. The survival rate was 95.2%, with six implants lost over a mean implants follow-up time of 47.68 ± 20.00 months. The horizontal bone gain ranged from 0.00 to 6.86 mm, with a mean gain of 2.85 ± 1.44 mm. An average of 5.5 ± 1.5g of DBBM was used per patient, and in 73.7 % of the cases, a flapless surgery was possible for implant placement, and in 92 implants an immediate loading was possible with a provisional overdenture. The final rehabilitation was accomplished with a fixed prosthodontics in 16 patients with a mean prosthesis follow-up time of 38.4 ± 22 months. The mean bone width gain was higher when the initial bone height was higher than 8, 10 or 12mm compared to initial bone heights lower than 8, 6 or 4mm. Conclusion: Within the limitations of this study, it is possible to affirm that the bone graft with 100% DBBM in atrophic maxilla is a reliable treatment and allow the rehabilitation with implants with a high survival rate; and the higher the initial bone height, the greater the gain in bone width.