## 3 Results  
Comparison between the baseline temperature (M = 27.4 \({}^{\circ}\)C; S.D. = 1.92 \({}^{\circ}\)C) and the temperature rise caused by the GG drills (M = 29.5 \({}^{\circ}\)C; S.D. = 1.76 \({}^{\circ}\)C) resulted in significant difference with a large effect size [t(29) = 5.59; \(p<0.001\); [PERSON]'s d = 1.02], however, there was no significant difference [t(29) = 0.538; \(p=0.595\)] observed between the preparations with the first and the second modified GG. The results of the measurements during ultrasonic preparation showed that temperature rise was generated in every preparation period, since the temperature at the end of the preparation was always higher than at the baseline regardless of the preparation settings. The highest average temperature rise was achieved using P3 mode at a 60 s time interval. The temperature measured at baseline [Mean (M) = 27.5 \({}^{\circ}\)C; Standard Deviation (S.D.) = 1.45 \({}^{\circ}\)C] was significantly lower than the temperature measured at the end (M = 30.9 \({}^{\circ}\)C; S.D. = 4.77 \({}^{\circ}\)C) of the preparation period with medium effect size [t(34) = 4.22; \(p<0.001\); [PERSON]'s d = 0.71]. The first preparation showed the highest temperature increase, while the subsequent preparations within a period showed lower temperature rise. This observation was tested using one-way ANOVA, which showed a significant difference [F(3,102) = 6.48; \(p<0.001\); \(\eta^{2}_{\text{P}}\) = 0.16]in the value of temperature rise among some of the preparations (Figure 3). Differences between temperature rise within one period using paired-sample \(t\)-tests were as follows: preparations 1 vs. 2 [t(34) = 3.58; \(p\) = 0.006] and preparation 1 vs. preparations 3 and 4 [t(34) = 3.64; \(p\) = 0.005]) were significant, while there were no differences in preparation 2 vs. 3 [t(34) = 0.81; \(p\) = 0.848], preparation 2 vs. 4 [t(34) = 0.91; \(p\) = 0.804], and preparation 3 vs. 4 [t(34) = 0.01; \(p\) = 1.000]. When comparing the temperature at the end of each preparation to the temperature at the end of the subsequent irrigation, it was confirmed that rinsing with a 24 \({}^{\circ}\)C solution resulted in significant decrease of temperature measured at the external root surface with a large effect size (Figure 3). Preparation mode was found to have a significant effect on temperature change with a large effect size [F(1,24) = 219.7; \(p<0.001\); \(\eta^{2}_{\text{P}}\) = 0.90]. The preparation with the P3 mode was associated with a greater temperature increase than preparation with the E5 mode (Figure 4). Statistically significant differences with a large effect size were also observed based on the duration of the preparation [F(2,24) = 25.8; \(p<0.001\); \(\eta^{2}_{\text{P}}\) = 0.68]. The differences between the tested durations using mixed ANOVA were as follows: 30 s vs. 45 s [t(24) = 3.03; \(p\) = 0.015; [PERSON]'s d = 1.36), 30 s vs. 60 s [t(24) = 7.15; \(p<0.001\); [PERSON]'s d = 3.20], and 45 s vs. 60 s [t(24) = 4.12; \(p\) = 0.001; [PERSON]'s d = 1.84]. Furthermore, the interaction of the variables, such as preparation mode and duration, also showed a significant effect [F(2,24) = 24.7; \(p<0.001\); \(\eta^{2}\)p = 0.67] on the temperature rise. To test the fourth hypothesis, Group 6 and Group 7 (control group)--set to the same parameters, except the thermal-conductive medium--were compared using independent-samples \(t\)-tests, which revealed that the temperature increase was significantly lower with a large effect size [t(8) = \(-\)16.4; \(p\) < 0.001; [PERSON]'s d = \(-\)10.4] in the preparation with the conductive medium. Additionally, the results of the paired-sample \(t\)-test showed that the light of the microscope had no significant effect [t(4) = 2.45; \(p\) = 0.07] on the temperature changes during removal of a fractured segment.