A prospective study on the accuracy of mucosally supported stereolithographic surgical guides in fully edentulous maxillae.

BACKGROUND

Flapless implant placement using guided surgery is widespread, although clinical publications on the precision are lacking.

PURPOSE

The purpose of this study was to evaluate the accuracy of mucosal-supported stereolithographic guides in the edentulous maxillae.

MATERIALS AND METHODS

Seventy-eight OsseoSpeed™ implants (Astra Tech AB, Mölndal, Sweden) of 3.5 to 5 mm width and 8 to 15 mm length were installed consecutively in 13 patients. Implants were functionally loaded on the day of surgery, and implant location was assessed with a computed tomography scan. Mimics 9.0 software (Materialise N.V., Leuven, Belgium) was used to fuse the images of the virtually planned and actually placed implants, and the locations, axes, and interimplant distances were compared.

RESULTS

One implant was lost shortly after insertion because of abscess formation caused by remnants of impression material. Seventy-seven implant locations were analyzed. The deviation at the entrance point ranged between 0.29 mm and 2.45 mm (SD: 0.44 mm), with a mean of 0.91 mm. Average angle deviation was 2.60° (range 0.16-8.86°; SD: 1.61°). At the apical point, the deviation ranged between 0.32 mm and 3.01 mm, with a mean of 1.13 mm (SD: 0.52 mm). The mean deviation of the coronal and apical interimplant distance was respectively 0.18 mm (range 0.07-0.32 mm; SD: 0.15) and 0.33 mm (range 0.12-0.69 mm; SD: 0.28). These deviations are lower than the global coronal and apical deviations.

CONCLUSION

The present study is the first to investigate the accuracy of stereolithographic, full, mucosally supported surgical guides in the treatment of fully edentulous maxillae. Clinicians should be warned that angular and linear deviations are to be expected. Short implants show significantly lower apical deviations compared with longer ones. Reasons for implant deviations are multifactorial; however, it is unlikely that the production process of the guide has a major impact on the total accuracy of a mucosal-supported stereolithographic guide.