## 2 Materials and Methods
### Physical and Mechanical Tests of Ca-SZ(CS) and Ca-SZ(CC) Sintered at Different Temperatures  
Eight specimens from both Ca-SZ(CS) and Ca-SZ(CC) groups sintered at different temperatures were analyzed with an X-ray diffractometer (XRD) (Shimadzu XRD-6000 powder diffractometer) using Cu K\(\alpha\) radiation (\(\lambda\) = 1.5406 A, 40 kV at 160 mA) at a scan rate of 0.05\({}^{\circ}\) 20 s\({}^{-1}\).  
Another eight specimens, from each group sintered at four different temperatures, were analyzed using a scanning electron microscope (SEM) (LEICA EM SCD005, Bannockburn, IL, USA). Specimens were then polished using an electric polishing machine (EXAKT 400 CS, AW110, Oklahoma City, OK, USA) with 300 mm Schleifscheiben sandpaper discs (Hermes Schleifmittel GmbH & Co. KG, Hamburg, Germany) at different grit sizes (P500, P800, P1000 and P1200) for 15 min for each grit, at 5000 rpm. Water was used to prevent the overheating of the samples. The sandpaper was changed for every sample. After that, the polished specimens were then re-analyzed using the SEM machine.  
Forty specimens from both groups, sintered at four different temperatures (\(n\) = 5), were weighed on a precision balance using Mettler Toledo DA110 toploading electrical balance (Tokyo, Japan), before and after immersion in double distilled water (DDW), for actual and suspended weights, respectively. Archimedes' principle was used to measure the density of sintered specimens. The following formula was used to calculate the density [18].  
\[\rho=\frac{\text{actualweight}}{(\text{actual}-\text{suspended})}\times\rho_{ \text{w}} \tag{1}\]  
where, \(\rho\) is the calculated density (g/cm\({}^{3}\)) and \(\rho_{\text{w}}\) is the density of the water (g/cm\({}^{3}\)).  
Forty specimens with dimensions of 25 mm \(\times\) 2 mm \(\times\) 2 mm were measured with vernier calipers and cut using a micro motor handpiece driven at 30,000 rpm for a flexural strength test (\(n\) = 5). Another 40 specimens with dimensions of 6 mm height \(\times\) 4 mm diameter (International Standards Organization (ISO) no. 9917 (2000)) were prepared for a compressive strength test (\(n\) = 5). Another 40 specimens measuring 30 mm \(\times\) 10 mm \(\times\) 2.5 mm (International Standards Organization (ISO) Specification no. 1567) were prepared for the Vickers hardness test (\(n\) = 5). The cut specimens were polished using the same protocol mentioned above. The flexural strength and compressive strength of the specimens were tested using the universal testing machine (Shimadzu, Model: AGX plus 20 kN, Kyoto, Japan) at the crosshead speed of 0.75 mm/min. The formula used for calculating the flexural strength and compressive strength was: Flexural strength = 3 PL/2 bd\({}^{2}\) where, P is the maximum force applied, L is the span length, b is the width, d is the thickness; Compressive strength = 4P/\(\pi\)d\({}^{2}\) where P stands for maximum force applied and d is the specimen diameter. For measuring hardness, a load of 1000 g = 9.81 newtons earth was placed on the top surface of the polished surface of the specimens by the Vickers hardness indenter.  
Statistical Analyses  
The one-way ANOVA test was used to analyze the means of flexural, compressive, Vickers hardness and density of the materials sintered at different temperatures, with \(p\) < 0.05 considered as significant. After checking the equal variance, the post-hoc Tukey test was used for multiple comparisons between the groups. The independent t test was used to analyze the mechanical and physical strengths between Ca-SZ(CS) and Ca-SZ(CC), with \(p\) < 0.05 considered significant.