Congruency of stereo lithographically produced surgical guide bases made from the same CBCT file: a pilot study

This is a pilot study evaluating the effect of the algorithms and production processes of four commercial manufacturers of stereolithographically produced surgical guide.

A singular Dicom file was used to produce six distinct duplicate dentures, which function as the base for surgical guides. The duplicate dentures were repeatedly fitted (n = 10) into an impression of the occlusal surface of the original scan appliance. The gaps between the incisal edge of teeth #8 and #9 and the corresponding imprints in the vinyl polysiloxane impression were photographed, digitally recorded, and measured in a blinded fashion.

Nobel Biocare mean was 0.56 mm (range 0.49-0.65), I-dent mean was 0.57 mm (range 0.31-0.74), Materialise II mean was 1.12 mm (range 0.90-1.40), Blue Sky Bio II mean was 1.13 mm (range 0.93-1.35), Materialise I mean was 1.43 mm (range 1.21-1.86), and Blue Sky Bio I mean was 2.17 mm (range 2.06-2.34). The difference between the fit of the Nobel Biocare and the I-dent guide bases and the guide bases from Materialise and Blue Sky Bio is statistically significant (p < .05).

The algorithms and production processes of the different manufactures do influence the congruency outcome of the produced surgical guide bases. Within the limits of this study, we were unable to produce a perfect fit, although some duplicate dentures showed minimal errors. The implications of the discrepancies need further study.