# Degree of Conversion and Mechanical Properties of Modern Self-Adhesive Luting Agents
## 3 Results  
Representative force-indentation depth graphs for the dual- and self-curing modes of the materials tested are illustrated in Figure 2. The left curve peak shifting in the dual-cured materials indicates increased HM hardness, whereas the steeper the unloading curve the higher the indentation modulus (E\({}_{\text{IIT}}\)). The results for HM, EIT, and n\({}_{\text{IIT}}\) are summarized in Table 2. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Product** & \multicolumn{2}{c}{**HM (N/mm\({}^{2}\))**} & \multicolumn{2}{c}{**E\({}_{\text{IIT}}\) (GPa)**} & \multicolumn{2}{c}{**n\({}_{\text{IIT}}\) (\%)**} \\ \hline  & **DC** & **SC** & **DC** & **SC** & **DC** & **SC** \\ \hline PSP & 329 (39)a,A & 239 (23)a,B & 7.6 (0.8)a,A & 6.1 (0.5)a,B & 42.7 (2.9)a,b,A & 40.9 (0.3)a,B \\ \hline PSU & 276 (16)a,A & 235 (14)a,B & 6.4 (0.5)a,A & 5.3 (0.4)a,B & 43.4 (1.4)a,A & 40.7 (0.8)a,B \\ \hline PV5 & 325 (29)a,A & 257 (15)a,B & 7.5 (0.9)a,A & 6.3 (0.4)a,B & 39.5 (0.6)b,A & 36.3 (1.1)a,B \\ \hline SPC & 306 (40)a,A & 290 (17)a,A & 7.2 (1.3)a,A & 6.5 (1.3)a,B & 40.7 (1.2)a,b,A & 36.8 (0.6)a,B \\ \hline THC & 274 (23)a,A & 164 (8)b,B & 6.6 (0.4)a,A & 5.1 (0.2)a,B & 39.8 (1.4)b,A & 32 (1.8)b,B \\ \hline \hline \end{tabular}  
* Means and standard deviations (in parentheses). Same low-case letters show mean values with insignificant differences between the products within the same curing mode, whereas same upper-case letters show mean values with insignificant differences for the same product between the two curing modes (\(p>0.05\)).  
\end{table} 
Table 2: The results of HM, EIT and n\({}_{\text{IIT}}\) for the materials tested in dual-curing (DC) and self-curing (SC) modes *. For HM, data distributions passed normality (\(p\) = 0.385, \(>\)0.05) and equal variance tests (\(p\) = 0.268, \(>\)0.05). Two-way ANOVA demonstrated a significant interaction between the independent parameters (\(p\) = 0.02), therefore the main effects of the parameters could not be properly interpreted. There was no statistically significant difference between the materials within the DC and SC groups, except for the significantly lower values of TCH in the SC group (\(p\) < 0.001). Comparison between the two curing modes demonstrated statistically higher HM values in the DC mode in all materials, with the only exemption being the SPC, where insignificant differences were registered (\(p\) = 0.425). The results of E\({}_{\rm IT}\) passed normality and equal variance tests (\(p\) = 0.627 and 0.247 respectively, \(p\) > 0.05). The two-way ANOVA manifested a statistically significant difference only in the curing mode (\(p\) < 0.001), with no interaction with the material type (\(p\) = 0.056). In all materials, the dual-curing mode showed higher values from the self-curing mode (\(p\) < 0.001), without significant differences between the products within each curing mode. For n\({}_{\rm IT}\), although the results passed normality and equal variance tests (\(p\) = 0.931 and 0.223 respectively, \(p\) > 0.05), there was a significant interaction between the parameters (\(p\) = 0.006). Within the dual-curing group, the significant differences were limited between PSU-THC (\(p\) = 0.024) and PSU-PV5 (\(p\) = 0.045). Within the self-curing group, insignificant differences were found between PSP, PSU, PV5, and SPC (\(p\) > 0.05). Between the curing modes per material, all differences were significant. Representative indentation depth-time graphs used for the assessment of the C\({}_{\rm IT}\) are presented in Figure 3. The creep curves comprised of a steep initial part and a main horizontal part related to creep deformation. The dual-cured products exhibited lower indentation depth values at the testing period than the self-cured. The results of the C\({}_{\rm IT}\) measurements are summarized in Table 3. Data passed normality and equal variance tests (\(p\) = 0.918 and 0.651 respectively, \(p\) > 0.05).