## 3 Results  
A total of 20 samples were tested, 10 for each test. Five samples were used in each group (test and control). All the specimens completed the mechanical tests, as planned. There was no statistically significant difference between groups in both the break point and displacement. The break point in the test group was 1953.19 \(\pm\) 543.73 N, while it was 2031.10 \(\pm\) 716.68 N in the control group. The difference was 77.90 \(\pm\) 504.56, and it was not statistically significant (\(p\) = 0.775). The displacement was 1.89 \(\pm\) 0.34 mm in the test group and 1.98 \(\pm\) 0.75 mm in the control group. The difference was 0.09 \(\pm\) 0.68, and there was no statistically significant difference (\(p\) = 0.763). The correlation between loading and displacement was found to be higher in the test group (0.842 versus 0.486). All the data are summarized in Table 1.  
When analyzing the break points, in the test group a first minor crack was noted at a mean loading value of 1400.00 \(\pm\) 274.00 N and displacement of 1.21 \(\pm\) 0.13. In the control group, the trend of the \"load-displacement\" graph was less consistent, probably due to minor cracks in the PMMA material, supported by the metal reinforcement. An example graph of the break points in the test and control groups is shown in Figures 7 and 8, respectively. After successfully completing all the static load tests, the very same protocol was followed for the dynamic cyclic test; 10 samples were tested, and all the specimens completed the fatigue tests as planned. Based on the obtained data, the new polymer-based restorative material (ONLY) endured a greater number of load cycles before being damaged in all tests. The threshold of each load at which the artifact failed (usually a fracture), along with the total number of cycles until failure, is reported in Table 2 and Figure 9.  
In the control group, the mean value was 2504.60 \(\pm\) 972.15 N, while in the test group the mean value was 3382.00 \(\pm\) 578.50 N. The averages of all groups were assumed to be equal. The difference between groups was 877.40 \(\pm\) 579.30 (\(p\) value = 0.121) N; \(p\) value equals 0.121181, [\(p\)(x \(\leq\) F) = 0.878819]. This means that if we were to reject H0, the chance of a type 1 error (rejecting a correct H0) would be too high: 0.1212 (12.12%). The larger the \(p\) value, the stronger it supports H0. Since \(p\) value \(>\alpha\), H0 is accepted. In other words, the difference between the sample averages of all groups is not big enough to be statistically significant. The test statistic F equals 3.006062, which is in the 95% region of acceptance: \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & & & & **Failure of the Specimen** \\ \cline{3-5}  & **Bridge** & **Sample Designation** & **Load Range** & **Load Amplitude** & **Total Number of Cycles until Failure** \\  & & & **[N]** & **Ds [N]** & **N** \\ \hline
1 & & A\_1 & 25-750 & 725 & 2447 \\ \hline
2 & & A\_2 & 25-750 & 725 & 2170 \\ \hline
3 & A & A\_3 & 25-1250 & 1225 & 4127 \\ \hline
4 & & A\_4 & 25-750 & 725 & 2263 \\ \hline
5 & & A\_5 & 25-500 & 475 & 1516 \\ \hline
6 & & B\_1 & 25-1000 & 975 & 3608 \\ \hline
7 & & B\_2 & 25-750 & 725 & 2946 \\ \hline
8 & (Non-metal) & B\_3 & 25-1250 & 1225 & 4280 \\ \hline
9 & & B\_4 & 25-750 & 725 & 2873 \\ \hline
10 & & B\_5 & 25-1000 & 975 & 3203 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Fatigue results for individual series of samples. Figure 8: Example of “load-displacement” graph in the control group. [0:5.3177]. The observed effect size f is large (0.61). This indicates that the magnitude of the difference between the averages is large. The \(\eta\)2 (\(\eta\)2 is a squared measure of association defined as the ratio of variance in an outcome variable explained by a predictor variable, after controlling for other predictors) equals 0.27. This means that the group explains 27.3% of the variance from the average (similar to R2 in the linear regression). The normality assumption was checked based on the Shapiro-Wilk test (\(\alpha\) = 0.05).