# Impact of the Enamel Cleaning Procedure during Debonding on Endodontium Temperature: In Vitro Tests
## 3 Results
\begin{table}
\begin{tabular}{c c c c c} \hline  & \(\mathbf{K_{0}}\) & \(\mathbf{K_{1}}\) & \(\mathbf{\tau_{1}}\) & \(\mathbf{\delta}\) \\ \hline Incisors & \(19.84\pm 5.47\) & \(108.33\pm 8.06\) & \(38.65\pm 6.57\) & \(0.001\pm 0.0005\) \\ Premolars & \(20.02\pm 6.82\) & \(112.50\pm 9.63\) & \(39.12\pm 8.22\) & \(0.001\pm 0.0005\) \\ \hline \end{tabular}
\end{table} 
Table 3: Fitting parameters of the one-exponential function for temperature drop during polishing without water cooling, showing the average for all tested samples (n = 32). \begin{table}
\begin{tabular}{c c c c c} \hline  & \(\mathbf{K_{0}}\) & \(\mathbf{K_{1}}\) & \(\mathbf{\tau_{1}}\) & \(\mathbf{\delta}\) \\ \hline Incisors & \(17.87\pm 4.87\) & \(98.74\pm 10.85\) & \(36.70\pm 9.21\) & \(0.003\pm 0.0005\) \\ Premolars & \(18.05\pm 6.44\) & \(92.35\pm 9.87\) & \(36.01\pm 11.45\) & \(0.002\pm 0.0005\) \\ \hline \end{tabular}
\end{table} 
Table 4: Fitting parameters of the one-exponential function for temperature drop during polishing with water cooling, showing the average for all tested samples (n = 32). Tooth density was also examined using computer microtomography methods. The proposed method allows us to not only to determine the average density of the entire tooth, but also to determine the density in relation to its individual tissues. In order to determine the density of individual tooth elements, their microtomographic scans were analyzed. An example of a microtomographic scan is shown in Figure 3, which shows five premolars and a density template. Using the interdependence between the level of grey of the microtomographic image and the density of the object, which is proportional to the greyness, areas corresponding to the defined density were determined within the template and then the average brightness of this area was determined in ImageJ. An example of a histogram is shown in Figure 4.  
Figure 4: Sample histogram obtained from ImageJ determining the average brightness of dentin. Figure 3: An example of a microtomographic scan containing five premolars with a density template. Then, for each of the four elements of the calibration standard, a calibration curve was created, allowing for the determination of the density of the samples. The average density of the dentin and enamel of premolars was 2.12 g/cm\({}^{3}\) and 3.58 g/cm\({}^{3}\), respectively (Table 5). In turn, the density of dentin and enamel of incisors was 2.09 g/cm\({}^{3}\) and 3.62 g/cm\({}^{3}\), respectively (Table 5). The obtained thermokinetic results were correlated with the obtained dentin and enamel density results for premolars and incisors. It has been shown that there is no statistically significant correlation between thermokinetic parameters (time constant \(\tau\), amplitudes of exponential functions, Figure 5). The maximum achieved temperature of the vestibular wall of the pulp chamber during polishing was 52.34 \({}^{\circ}\)C without the use of water cooling, and the maximum obtained temperature of the vestibular wall of the pulp chamber during polishing was 43.15 \({}^{\circ}\)C using water cooling (Figure 6). Figure 5: An example of a calibration curve for the density of template bars, together with the parameters of a linear function necessary to identify the density of dentin in premolars 1–5. \begin{table}
\begin{tabular}{c c} \hline \hline
**Sample** & **Density (g/cm\({}^{3}\))** \\ \hline Dentin of premolars & 2.12 \(\pm\) 0.1874 \\ Enamel of premolars & 3.58 \(\pm\) 0.2015 \\ Dentin of incisors & 2.09 \(\pm\) 0.1433 \\ Enamel of incisors & 3.62 \(\pm\) 0.2701 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Density of dentin and enamel for premolars and incisors. The time after polishing at which the safe temperature of 40 \({}^{\circ}\)C was obtained without water cooling was 29.4 s, while for polishing with water cooling, this safe temperature was reached in 34.6 s.  
There was no correlation between the obtained maximum and average temperature in the region of interest (ROI) with either enamel density or dentin density.