The effect analysis of different scanning strategies and software parameters on digital impressions in implant-supported prosthesis

Aim: The aim of this study is to analyze the effects of segmental and complete arch digital impression scanning on different scanning parameters (min- max. focal depth) in the software, implant position and count on the accuracy of digital impressions. Material and Method: Placing angled and straight implants on 3 various epoxy models, 5 different case scenarios have been created. Group 1A (segmental scan: angled implant placed on tooth number 11), Group 1P (segmental scan: straight implant placed on tooth number 16), Group 2P (segmental scan: straight implants placed on teeth 26 and 27), Group 4 (complete-arch scan: posterior angled, anterior straight implants placed on teeth 32, 42, 34 and 44), Group 6 (complete-arch scan: straight implants placed on teeth 32, 34, 36, 42, 44 and 46). In every case scenario, digital impression scans have been recorded in the laboratory scanner for the reference data. Having changed minimum and maximum scanning depth parameters of the intraoral scanner via specific software, 10 different digital impression scans have been conducted for each depth perception in each created group. Recorded digital impressions have been compared with the help of software and deviations have been calculated. Between-groups comparision of acquired test data has been performed through one-way ANOVA, in-group comparisons have been made through Student`s T-test. Results: Comparing trueness and precision values of the scanner for minimum and maximum scanning depth, statistically significant results have been detected. Complete-arch scans, compared with segmental scans, have shown a higher deviation value (p <0.05). It has been seen that the increase of the distance between the angle and implants is effective on the accuracy of the intraoral scanner. While comparing trueness and precision values of the scanner for minimum and maximum scanning depth, statistically significant differences among some groups (Group 2P, Group 4, Group 6) have been detected (p <0.05) Conclusion: Taking scan focus at a low level in software parameters can enable to obtain highly accurate digital impressions. Straight implant body, scanning field length, the existence of arch curvature in scan field, the increase of the distance between the implants effect the accuracy of digital impressions.