## 3 Results
### Control Specim Analysis and Experimental Data Processing
#### 3.2.3 Type 3 Test Specimens
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Cycle**} & **Average (Max.** & **Deviation** & **Elastic Modulus** & **Deviation** \\  & **Stress) (MPa)** & **(MPa)** & **(GPa)** & **(GPa)** \\ \hline M1 MC & 11.0 & 0.9 & 783 & 14 \\ M1C1 & 10.7 & 0.7 & 780 & 95 \\ M1C2 & 13.4 & 1.0 & 935 & 122 \\ M1C3 & 12.3 & 1.8 & 1227 & 235 \\ M1C4 & 11.5 & 1.4 & 1050 & 338 \\ \hline \hline \end{tabular}  
* The data present the mean values and standard deviations of the maximum tensile strength and elastic modulus of the reference specimens and the specimens of putty M1 subjected to aging cycles. Source: Authors’ own elaboration, DorART Project, 2025.  
\end{table} 
Table 6: Average and standard deviation of maximum stress and elastic modulus. Figure 11: The tensile test results for MIMC-3. (**a**) The displacement–force curve recorded during material preparation and application. (**b**) The stress–strain curve obtained post drying, based on strain data from a video extensometer (black) and transverse strain from crosshead displacement (blue). These measurements allowed for evaluation of the material’s behavior both along the direction of the applied load and perpendicular to it. Source: Authors’ own elaboration, DorART Project, 2025. Figure 12: Placement of specimens between serrated flat jaws. _Source:_ DorART Project, 2025. **Results**. Based on the analysis of these graphics and a comparison between the different filler formulations evaluated, it was determined that the formulations with the highest mechanical strength were M1 (13 MPa) and M4 (13 MPa), both of which achieved their peak values in the second cycle. On the contrary, formulations M8, M5, and M6 were classified as the least resistant, and they also showed high fragility during demolding. In general terms, the mechanical strength of most formulations reached its maximum in the second cycle, followed by a progressive decline in subsequent cycles, which may indicate a loss of structural capacity as a consequence of aging. However, some exceptions to this pattern were observed:  
* M5 showed a progressive increase in strength throughout the cycles, although with very low stress values. * The strength of M7 reached its maximum in the first cycle and then decreased. * M3 presented high initial strength, which dropped in the second cycle and then increased progressively until the fourth cycle, suggesting that this specimen had more stable long-term mechanical behavior. * **ATR-FTIR Spectroscopic Characterization. ** A chemical-mineralogical analysis of the fillers was performed using ATR-FT-IR spectroscopy in order to characterize the molecular structure and chemical composition of the materials and to assess possible changes induced by the aging cycles. An ATR-FTIR spectroscope Vertex70 spectrometer (Bruker Optik GmbH 2012, Ettlingen, Germany) was used with MKII Golden Gate with an ATR accessory (Specac(r), Orpington, UK) and an FR-DTGS--a fast-recovery deuterated triglycine sulfate temperature-stabilized coated detector. A total of 32 scans were collected at a resolution of 4 cm\({}^{-1}\). The spectral range scanned was 500-4000 cm\({}^{-1}\). The spectra were processed using OPUS 7.2/IR software (Bruker Optik GmbH 2012, Ettlingen, Germany). The samples were analyzed directly. **Results**. In general, a reduction in the intensity of bands corresponding to hydroxyl groups [51] (-OH) located in the 3300-3400 cm\({}^{-1}\) region was observed, which can be interpreted as a consequence of the loss of structural or surface-bound water. This behavior was consistent across most spectra and is associated with dehydration processes triggered by the thermo-hygrometric conditions applied during accelerated aging in the climate chamber. These trends are illustrated in Figure 14, which shows the spectral evolution of two selected filler materials across the aging cycles. Figure 13: The tensile strength evolution of the tested fillers across aging cycles (MC–C4).