## 5 Discussion  
Rotational speed builds up the momentum of the cutting edge of the drill to cut small homogeneous fragments of tissue without causing too deep damage to the surrounding tissue. Good drills should have this momentum at the speed range of approx. 1200 rpm because it is considered optimal for bone tissue [32]. Lower rotational speeds may be insufficient to uniformly remove tissues of a particular thickness. On the other hand, too high a rotational speed of the drill can generate excessive heat damage to the adjacent bone [32]. To prevent this, cooling solutions are used to remove excess heat. Because the fluids in the experiment could have been in contact with the drill only on its outer surface, the cooling efficiency, in this case, should be related to the ability of the drill to evenly distribute heat throughout its mass. The obtained results indicate that cutting speed has a direct impact on the drill hole wall structure. In the experiment carried out, the Osstem drill was characterized by good cutting properties at all speeds and cooling methods, except for speeds I and II when cooled at room temperature. Under these conditions, minor disturbances in bone structure appeared in the form of jagged fibers. In this case, it means that drilling under such \begin{table}
\begin{tabular}{l c c c c} \hline \hline \multirow{2}{*}{**Parameters**} & \multicolumn{3}{c}{**The Quality of the Drill Hole**} & \multirow{2}{*}{**Fischer’s Exact Test**} \\  & & \multicolumn{1}{c}{**Surface**} & \\ \cline{2-4}  & **OK** & & **NOK** \\ \cline{2-4}  & \(n\) & **\%** & \(n\) & **\%** \\ \hline System: & & & & \\ Osstem & 2 & 33.3\% & 7 & 33.3\% \\ Straumann & 4 & 66.7\% & 5 & 23.8\% \\ Neobiotech S-Wide & 0 & 0.0\% & 9 & 42.9\% \\ \hline Environmental conditions: & & & & \\ Without cooling & 4 & 66.7\% & 5 & 23.8\% \\ With cooling at room temperature & 2 & 33.3\% & 7 & 33.3\% \\ With cooling with normal saline at 4 \({}^{\circ}\)C & 0 & 0.0\% & 9 & 42.9\% \\ \hline Cutting speed \(v_{\text{c}}\)(m/s) & & & & \\ \textless{}0.22 & 6 & 100.0\% & 6 & 28.6\% \\ \textgreater{}0.22 & 0 & 0.0\% & 15 & 71.4\% \\ \hline \hline \end{tabular}  
*: tendency to a statistically significant value; **:**: statistically significant.  
\end{table} 
Table 2: Distribution of study preparation parameters in the groups differing in the quality of the drill hole surface. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**System and Cooling**} & \multicolumn{3}{c}{**High Quality**} & \\ \cline{2-4}  & **OK** & **NOK** & **OR [95\% CI]** \\ \hline For: Straumann & 4 & 5 & 6.40 [0.89–46.00] \\ For: Osstem or & 2 & 16 & 0.16 [0.02–1.12] \\ Neobiotech S-Wide & & & & \\ For: without cooling & 4 & 5 & 6.40 [0.89–46.00] \\ For: with cooling & 2 & 16 & 0.16 [0.02–1.12] \\ \hline \hline \end{tabular}  
* OR—odds ratio, CI—confidence interval.  
\end{table} 
Table 3: The likelihood of a high-quality drill hole surface occurrence in relation to the used system and cooling/non-cooling condition. conditions should take place at higher speeds because at 1500 rpm, this effect was not observed. Similar results were obtained by [PERSON] et al. [32]. The Straumann drill was characterized by very good parameters at all rotational speeds and cooling methods. Small residues of bone chips were observed at speeds I and II with cooling at 4 \({}^{\circ}\)C. This can be related to the shape of the working part of the drill and the materials used that evenly distribute heat. In the case of the Neobiotech S-Wide application, slightly greater destruction of adjacent tissues and tissue carbonation were observed for the same conditions. In addition, areas of compression and distortion of adjacent tissues were visible. Initial mechanical engagement in the healing phase is important for the remodeling process [33; 34; 35; 36]. The osseometigration process results in achieving secondary stability, which is a direct contact between the intact bone and implant surface [21; 22; 37].