## 4 Discussion
The same team, in another study, chose to compare instead the performance of 12 dentists, 12 dental technicians and 12 dental students on the same type of test and evaluated the planning execution time in this case too. This resulted in a shorter time for dental technicians in the initial test, with a progressively less important difference in the following tests [33]. [PERSON] et al. [40] selected, instead, a group of dental surgeons with 5-10 years' experience and a group of dental surgery students and asked them to virtually plan the insertion of dental implants in a completely dedentulous patient's maxilla in two stages, with and without a virtual mock-up obtained by an oral scan of the patient's mouth. The team evaluated the discrepancies between the two groups and the two tests, showing how digital planning, helped by a virtual mock-up, is more useful for students to reduce the risk of badly placed implants. Some of these studies also evaluated the tests made with two different forms of software to show potential discrepancies in the planning process [31; 32; 33]. Excluding [PERSON] et al. [40], no other study evaluated the accuracy of the work. An important result is that 88,2% of all clinicians that positioned the screw in the \"safe zone\" answered positively, in the pre-test survey, to the \"clinical or theoretical experience\" question. The totality of the sample that achieved \"bicorticalism\" in the test answered positively to the same question. On the same topic, almost all the sample placed the screw without hurting the incisive foramina and roots. From these results, it is clear that many clinicians in the sample have experience on the topic and, even if basic, this experience is reflected in the good results in the test. All the clinicians who answered positively to the \"digital knowledge\" questions showed shorter performances than the others in the first test, even if, in another field of investigation, this result can be considered similar to that in [PERSON] et al. 's study [33]. This gap was then reduced in the second test, a value that is reflected in the continuous reduction in the influence of pre-existing digital knowledge [32]. In all the sample there was, instead, a significant reduction in time from the first to the second test, reflecting a great improvement. From these results, it seems that the use of the software's settings represents a mechanical task that may be accomplished at a progressively quicker speed each time; hence, this may contribute to a reduction in the total planning time required. The evaluation of \"Surgical Guide realization\" did not show any significant difference between the two tests and was not affected by clinical experience and digital knowledge. A possible reason for this may be attributed to the pre-test explanation via the video guide lesson on the software's use, and to the basic instructions delivered by the members of the study redaction team. The limitation of this study is the small number of participants belonging to each group and the small total sample. A future prospective research avenue is to repeat the test more than just twice, to provide a larger sample and to carry out the clinical treatment by printing the guide and inserting the implants in the patient's mouth.