Fig. 4

a, b Measurement of the emergence angle (the angle between a parallel to the implant axis through the interproximal border of the implant collar (green line) and the tangent to the restoration from the implant collar border (blue line) in the Zirkonzahn software (Zirkonzahn GmbH, Gais, Italy) as described by Katafuchi et al. [19] (a and b). The red line indicates the same measurement from the border of the adhesive base (AB) instead of the implant collar border (a). Depending on the design of the AB and crown, the blue line can cut the border of the AB. Due to the lack of an AB only one measurement was performed for the perfabricated titanium abutments (b).