###### Abstract  
The objective of this in vitro study is to evaluate and compare the precision of digital impressions obtained using intraoral scanners and photogrammetry devices for full-arch implant-supported oral rehabilitation. Three reference models were created with various spatial distributions of Straumann implants, according to the Carames I Classification: (i) option A with six implants; (ii) option B with four implants; and (iii) option C with four implants. Thirty digital impressions were taken for each of the reference models: ten with the Intraoral 3 Shape Trios 3 scanner, ten with the Medii 500 intraoral scanner, and ten with the PIC Dental photogrammetry device. Intra-group best-fit overlaps were performed between the virtual models obtained, and accuracy was evaluated using root mean square (RMS) values. A significance level of \(p=0.05\) was defined. Mean values were statistically analyzed using the Kruskal-Wallis test. All scanners studied showed high precision, with RMS values similar for each implant distribution. The PIC Dental photogrammetry device demonstrated the best results for the CCI A and B distributions, with mean values of 11.28 \(\upmu\)m and 14.44 \(\upmu\)m, respectively. For the CCI C distribution, the 3 Shape Trios 3 scanner achieved the best result, with a mean value of 5.96 \(\upmu\)m. Among all devices, the implant distribution showing the highest RMS values was the CCI B, with mean values between 14.44 \(\upmu\)m and 16.96 \(\upmu\)m. The PIC Dental device was the only method that did not exhibit statistically significant differences in RMS values across the different distributions studied, indicating that its performance is unaffected by distribution variations. No statistically significant differences (\(p<0.05\)) were observed in the RMS values among the three types of scanners. Overall, a smaller number of implants and closer distribution between them resulted in improved precision for digital impressions in full-arch implant rehabilitation. d ARTIC 2025, 15, 1388 +
Footnote †: journal: applied sciences  
article  
[color=0.5,nobreak=0 pt,nobreak=true] _Article_  
[color=0. customized dental prostheses [1]. In this context, achieving a passive fit between the prosthetic structures and implants is considered a key factor for preventing mechanical and biological complications, thereby ensuring the long-term success of implant-supported prosthetic treatments [1; 2]. In terms of mechanical complications, forces generated by tension, compression, and flexion due to non-passive adjustments can lead to fractures of screws, prostheses, or implants. Biological complications may also arise from a poor prosthetic fit, as the increased space between the prosthesis and implant promotes the accumulation of microorganisms, potentially leading to issues in the supporting tissues [3]. Several authors have stated that achieving absolute passive fit is nearly impossible due to the numerous steps involved in the prosthetic manufacturing process, particularly in full-arch implant-supported rehabilitation [4; 5]. However, a small margin of error is generally considered acceptable and is unlikely to result in future complications [3; 6]. The quality of the impression is a critical determinant in achieving a passive fit of prosthetic structures, as osseointegrated implants cannot accommodate inaccuracies due to the absence of a periodontal ligament. Consequently, even minor discrepancies can lead to prosthetic maladjustment, which may compromise long-term success [7; 8]. It has been reported that the maximum acceptable lack of adjustment is 150 \(\upmu\)m [2; 9], while others suggest a limit of approximately 60 \(\upmu\)m [3; 10] and 50 \(\upmu\)m [8; 11]. Moreover, various reviews have concluded that there is no consensus on the fit of implant-supported prostheses [12; 13]. For this reason, some authors suggest that errors should be limited to 30-50 \(\upmu\)m to prevent mechanical and biological complications [12; 14].