Journal of Dentistry and Oral Care

Background: A minimum of four implants should be used in edentulous maxillae to anchor a dental prosthesis. A wide anterior/posterior distribution of the implants is advantageous. Besides bone grafting, short or tilted implants are used to achieve this in atrophic edentulous maxillae. The implants define a polygon that should be as large as possible. This study investigated the differences in the surface area of the polygon of implant-retained prosthesis support with straight and tilted dental implants in edentulous maxillae. Materials and Methods: In fifty DICOM-datasets of atrophic edentulous maxillae, four different implant configurations using four implants each were virtually planned and measured. The distal implants were either straight (12, 10 or 8 mm long) or tilted ( ≥ 12 mm) and positioned as distally as possible without bone grafting. Results: The mean surface area of the prosthesis support polygon with straight implants distally, 12 mm in length, was 263 mm2 (SD: 134, range: 36 to 590 mm2). The use of 2 mm shorter implants resulted in an enlargement of the support polygon of about 20 %. By using tilted implants (42 to 45°), the size of the polygon (mean: 456 mm2, SD: 180, range: 151 to 949 mm2) was increased by another 20 % compared to straight 8 mm long implants. Conclusion: This study demonstrated that the implant-retained prosthesis support area can be enlarged by reducing the implant length of distal implants, and it can be further enlarged in edentulous maxillae by using tilted implants. *Corresponding author: Stefan Wentaschek, DMD, MSc. Department of Prosthetic Dentistry, University Medical Center of the University of Mainz, Augustusplatz 2, 55131 Mainz, Germany, Tel: +49-6131 17 3062/ Fax: +49-6131 17 5517; E-mail: [email protected]