Fig. 1

Two different plaster models were prepared, representing three different situations in the maxilla. The first model (a) was a partially edentulous maxilla (PEM), with an implant analog in position #23 (left upper canine), to simulate the situation of an implant-supported single crown (SC), and with two implant analogs in position #14 and #16 (respectively right first premolar and first molar), to simulate the situation of an implant-supported partial prosthesis (PP). The second model (b) was a totally edentulous maxilla (TEM), with implant analogs in position #11, #14, #16, #21, #24 and #26 (right and left central incisors, first premolars and first molars), to simulate a situation of an implant-supported fixed full-arch (FA) prosthesis. All models presented pink gums in the areas of implant analogs, with high-precision non-reflective polyether-ether-ketone (PEEK) scanbodies (Megagen®, Daegu, South Korea) screwed on the implant analogs