Digital Evaluation of the Positional Accuracy of Implant Scan Bodies in All-On-Four Patients Using Digital Approach-A Controlled Clinical Trial.

AIM: To compare the positional accuracy of the scan body obtained in indirect and direct-indirect digital approaches with that of the direct digital approach. MATERIALS AND METHODS: Twenty implants were placed, each maxilla of four, using All-On-Four concept in five patients. Three impression techniques have been applied to each patient, namely 1) direct digital approach, 2) indirect digital approach, and 3) direct-indirect digital approach. With the use of specialized 3D inspection and metrology software, the difference in scan body position between the groups was calculated. RESULTS: The average total deviation values for the two groups under examination were 343.15 ± 3.4 μm and 402.79 ± 2.6 μm, respectively. For each of the study groups, the deviation measurement between the superimposed scan bodies revealed statistically significant (P = 0.006) differences. A statistically insignificant difference between the compared groups was found by the post hoc analysis (P = 0.006 and 0.014). CONCLUSION: The direct-indirect digital impression group displayed the least positional accuracy (402.79 ± 2.6 μm). The accuracy of all three digital impression-making approaches in implant dentistry appears to be clinically acceptable and adequate for all types of implant restorations, especially in All-on-Four treatment modality.