Effect of splinting scan bodies on the trueness of complete arch digital implant scans with 5 different intraoral scanners

Statement of problem. The absence of fixed reference points can affect the trueness of complete arch intraoral digital implant scans. The effect of splinting intraoral scan bodies (ISBs) or the inclusion of artificial landmarks (AL) on the trueness of complete arch digital implant scans is still unclear. Purpose. The purpose of this study was to analyze the effect of splinting ISBs or the inclusion of AL on the trueness of complete arch digital implant scans with 5 intraoral scanners (IOSs). Material and methods. Six tissue-level dental implants (Straumann Tissue Level) were placed in an edentulous patient, and the correspondent definitive cast was digitized with a desktop scanner (IScan4D LS3i) to obtain the reference digital cast. Digital scans (n=10) were performed with 5 IOSs: TRIOS 4, Virtuo Vivo, Medit i700, iTero Element 5D, and Cerec Primescan. Three different scanning techniques were evaluated: conventional (cIOSs), splinted (sIOSs), and AL (AL-IOSs). The scan data obtained were imported into a metrology software program and superimposed to the reference digital cast by using a best-fit algorithm. The overall deviations of the positions of the ISBs were evaluated by using the root-mean-square (RMS) error (alpha=.05). Results. The mean +/- standard deviation trueness values for the cIOSs, sIOSs, and AL-IOSs groups were 48 +/- 8 pm, 53 +/- 7 pm, and 49 +/- 11 pm, respectively, with no statistically significant differences ( P=.06). Significant differences were found for the IOSs used with each technique ( P<.001). Primescan (27 +/- 4 pm cIOSs; 28 +/- 3 pm sIOSs; 31 +/- 3 pm AL-IOSs) showed significantly higher trueness than iTero 5D (47 +/- 5 pm cIOSs; 47 +/- 4 pm sIOSs; 50 +/- 6 pm AL-IOSs) ( P=.002) and TRIOS 4 (93 +/- 18 pm cIOSs; 76 +/- 18 pm sIOSs; 107 +/- 13 pm AL-IOSs) ( P=.001) for all techniques. In addition, no significant differences were found between the techniques by using iTero 5D or Primescan ( P=.348 and P=.059, respectively). Conclusions. The cIOSs, sIOSs, and AL-IOSs techniques showed similar trueness. The IOS used influenced the trueness of complete arch digital implant scans. (J Prosthet Dent 2024;132:204-210)