Contrary to the research hypothesis, there was no difference in primary stability between manually and machine-driven inserted implants. To date, little is known about the influence of the insertion mode on the dental implant primary stability. Novsak et al. assumed a better primary stability in implants inserted manually and suspected that this behavior was related to a higher tactile sensation in hand-driven implantation. In contrast, movements during insertion and a greater amount of rotational stress due to higher torque values could explain a poor outcome during manual insertion. In accordance with the results of the present study, it can be assumed that there is no difference between manual and machine-driven insertion modes and that surgical experience in general and especially in using either procedure seems to be more important than the insertion mode itself.

The aim of this study was to analyze the influence of protocol and insertion mode on dental implant primary stability ex vivo. Implants inserted via standard protocol showed higher stability values than implants inserted via an over-dimensioned protocol. Interestingly, the study demonstrated that the latter nevertheless exceeded the primary stability recommended for immediate implant insertion so that the use of ODPs might be preferable to reduce the level of compressive stress. This study also showed that manual and machine-driven insertion modes exhibited equivalent primary stability values. Under the limitations of this study, it can be hypothesized that the choice of implant type in combination with the surgical drilling technique adapted to the quality of the bony implant site as well as patient-related factors and the surgical experience seems to be more important than the insertion mode itself. In the absence of guidelines and in consideration of the high number of implants inserted each year, further studies are needed to confirm or disprove these results and to improve the knowledge within this area.