## 4 Discussion  
This systematic review primarily aimed to evaluate the clinical evidence concerning the survival rates and complications associated with full-arch implant-supported prostheses created using digital methods compared to those obtained through conventional impression techniques. The clinical studies included in the review consistently demonstrated positive outcomes in rehabilitation treatments. This topic is significant because the effectiveness and accuracy of scanning to acquire single and partial implant-supported prostheses are well-documented in the literature [5; 29]. However, to scan completely edentulous arches, there are still challenges related to angular divergences, soft tissue scanning, and distance between implants. These factors can affect prosthetic adaptation and influence both complication rates and the survival of oral rehabilitation [5; 30]. Regarding implant positioning, the study by [PERSON] et al. [24] identified a difference of 85 \(\pm\) 25 \(\upmu\)m between the position of the implants in the digital and conventional groups. At the same time, [PERSON] et al. [21] found 162 \(\pm\) 77 \(\upmu\)m. [PERSON] et al. [25] emphasized that the number of implants and type of scan body used in the scanning can result in differences in the accuracy of implant positioning when comparing the digital with the conventional technique. In their study, the authors describe that the least distortion was observed in cases that used four implants and cylindrical scan bodies. [PERSON] et al. [21] did not find statistically significant differences despite also  
Figure 9: Risk analysis using the ROBIN-I scale [3; 4; 9; 21; 23; 24; 25]. evaluating such aspects. Basic clinical studies that evaluated discrepancies in conventional models describe values within a range of 150 to 200 \(\upmu\)m as clinically acceptable limits [31; 32]. This supports the conclusion that all studies included in this systematic review indicated the viability of digital scanning as an alternative to conventional impressions, considering final positioning adjustments. This aspect is directly related to the level of adaptation of the prostheses. Among the studies evaluated, there were reports of the need for new prosthesis fabrication due to maladaptation of the infrastructures. Therefore, radiographic analysis and precise verification of the prostheses should be considered for the correct clinical outcome [9; 25]. [PERSON] et al. [9] emphasized the need for rescanning, which in their study reached 20% of the digital group so the final design of the overdentures would be clinically acceptable. Given the clinically acceptable passivity and adaptation for both methods, these findings corroborate that the complication rates were statistically equivalent for both groups. Only four studies were included and evaluated in the meta-analysis for technical and biological complications [4; 6; 8; 20], and no significant differences were observed between the groups. This underscores the importance of our research. It is worth noting that the follow-up period ranged from 12 to 48 months. Only two studies allowed data collection and analysis regarding the need for additional time in case of repetition [4; 6]. The studies demonstrated that the digital group presented twice the number of repetitions than the control group. These results should be taken into account since several studies state that the working time for the digital method is reduced when compared to the working time for the conventional method; however, such studies do not consider the need for repetition time [29; 33]. In this context, it is important to highlight the need for adaptation to the software being used, the specific commercial brand, and proficiency in the scanning technique. Additionally, proper positioning and fixation of the scan body are crucial.