## 4 Discussion
In summary, the silicate-based group of ceramics, IPS e.max CAD, subjected to a 7 min heat treatment at 840 \({}^{\circ}\)C in an Ivoclar Vivadent furnace, showed superior mechanical parameters. In contrast, Vita Suprinity showed better MH and FT when treated in the same furnace, albeit with an extended time of 8 min. From a mechanical standpoint, diverse outcomes have been observed concerning the influence of temperature and sintering time on the properties of zirconium oxide, particularly in type 3Y-TZP. A study observed that a substantial increase in temperature and sintering time did not yield statistically significant differences in MH or FS. Nevertheless, these parameters did notably enhance the translucency and color rendering fidelity [60]. In contrast, another investigation yielded different results. For example, it was identified that the grain size in 3Y-TZP zirconia increases as the sintering temperature rises, reaching its maximum at 1700 \({}^{\circ}\)C. In addition, a significant negative correlation was established between sintering temperature and FS, as well as the contrast ratio (\(p\) < 0.001). This relationship is attributed to alterations in the grain structure, which could lead to a decrease in FS [61]. The results found by [PERSON] et al. evidenced a lower FS 480 \(\pm\) 111 MPa in e.max ZirCAD Ivoclar Vivadent using an AHT of 1550 \({}^{\circ}\)C for 2 h with a furnace of the same commercial company [41]. Interestingly, [PERSON] et al. proposed a different perspective, suggesting that a combination of high sintering temperature with reduced time can enhance the FR of zirconium [62]. Although previous research on 5Y-ZP zirconia has not shown significant effects on FRwith high-speed sintering schedules [63], this finding aligns with results obtained for the Katana STML Block using fast sintering protocols [34]. In the context of this RS, positive results on FS were achieved in a key study by [PERSON] et al. in 2020, reaching an FS of 1183 \(\pm\) 204 MPa for InCoris TZI/Dentsply Sirona. They used a specific heat treatment of 1510 \({}^{\circ}\)C for 15 min with a furnace of the same brand [37]. This theory is supported by a study that evaluated FR through a compressive test on InCoris TZI from Dentsply Sirona, employing two different heat treatments: One with the InFire furnace at 1650 \({}^{\circ}\)C for 8 h and another with SpeedFire at 1600 \({}^{\circ}\)C for 18 min. The results favored SpeedFire, registering a value of 1222.80 \(\pm\) 136.90 N [44]. In contrast, an analysis by [PERSON] et al. [42] on Razor Zirconia from U&C International showed an FS of 304 \(\pm\) 21 MPa with an AHT 1230 \({}^{\circ}\)C protocol for 2 h, indicating a considerable difference. This contrast can be attributed to variations in zirconia composition, specifically its microstructure, and the importance of following the manufacturer's recommendations regarding equipment and heat treatment protocols. Coinciding with previous trends, it is observed that the FR of 5Y-ZP is approximately half that of 3Y-TZP [64; 65]. Furthermore, an additional study by [PERSON] et al., in 2022, analyzed the impact of post-sintering processes on the FR of different monolithic zirconium oxides. The results revealed significant differences: For classically glazed (CzAG) zirconium oxide, the mean \(\pm\) standard deviation value of \(\sigma\) (MPa) was 1626 \(\pm\) 184, while for those with high translucency (HzAG), it was 671 \(\pm\) 96 [66]. In a complementary investigation, the same authors conducted a study in 2021 that focused on evaluating the impact of post-sintering processes on FT. The results indicated that CzAG presented values of 5.40 Gpa MH and 7.27 KIC FT, while HzAG recorded notably higher values of 5.53 Gpa MH and 10.91 KIC for FT [67]. These observations disagree with the data obtained by [PERSON] et al. in 2023, providing relevant information by performing a comparative analysis on various thermal effects over a 2 h period for Razor Zirconia/U&C International.