Cut-out-Rescan Procedure Under Rubber-Dam Isolation

Aim: This clinical study investigated the effect of the "cut-out-rescan" procedure under rubber dam isolation on restorative scanning trueness of four intraoral scanners. Materials and Methods: The initial scans were collected from 20 patients using 4 dental intraoral scanners (Trios 3, 3Shape; Cerec Primescan, Dentsply Sirona; iTero Element 5D, Align; iTero Lumina, Align). The 3-dimensional data was obtained from the right or left side of the mandibula between the canine-to-2nd molar area and recorded in .stl format. Then the 2nd premolar was cut with the cutting tool in the related scanner software in a range including 1mm from the adjacent teeth. The determined area was clinically isolated with the rubber-dam and the same quadrant was rescanned to let the software overlap with the cut-out area. The overlapped scan was recorded in .stl format as the second scan data. The first and second scan data from the 4 scanners were then transferred to the Oracheck (Dentsply Sirona) software program and digitally overlapped to measure the conformity. The deviations detected in the 1st premolar, 2nd premolar, and 1st molar were selectively and jointly assessed in distance (mm) and volume (mm3) for every scanner data. Robust ANOVA and Kruskal Wallis tests were used for the statistical analyses and the significance level was set at \<.050.