## 3 Results  
A fatigue loading test measures the resistance of a material against multiple cycling loads, which cannot destroy the object separately. After conducting the laboratory fatigue strength tests, the samples were carefully examined under magnification and analyzed according to the criteria described in the task methodology. All samples were found to have passed the fatigue test in the masticatory simulator without any of the listed complications. A compressive strength test measures the loadings that deform and destroy a material when opposite, pressing forces are applied. When the smashing force increases, the material first deforms and then fractures and is destroyed at the end. After performing the compressive strength tests, the tested objects were subjected to repeated microscopic analysis according to the same criteria. The obtained data are summarized in Table 3.  
The microscopic analysis showed that no deformations were present in the connecting screw or the abutment after conducting both tests. In all samples, there was visible destruction of the adhesive bond and breakdown of the monolithic restoration. Two patterns of fracture behavior were demonstrated. In Group A1, the fracture was in the area of the tooth neck, horizontally and circumferentially, while in all the other subgroups, the fracture line was longitudinal and divided the permanent crown into two halves (Figure 7). The statistical analysis compared the compressive force that caused the destruction of the suprastructures of the three study groups. Group A consisted of monolithic implant restorations made of zirconium dioxide and a titanium base. Group B consisted of monolithic zirconia implant restorations and a customized titanium alloy abutment, while Group C included monolithic lithium disilicate implant crowns and a customized titanium alloy abutment. Each of the three groups underwent ten observations: five of the upper maxillary incisors and five of the upper maxillary first molars. Analysis of variance was performed to compare the compressive strengths of crowns from the three groups. The average value of the compressive strength at which the structures in each group fracture is as follows: Group A, 5669.2; Group B, 3126.5; and Group C, 1850.6. Based on the average values, it can be concluded that the combination of materials used in Group A has the greatest resistance. The observed differences between the 3 groups were also highly statistically significant at a standard significance level of 0.05 (F = 35.7; \(p\)-value = 0.000). This clearly shows the differences in the stabilities of the suprastructures in the study groups. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Tested Characteristic** & **Group A** & **Group B** & **Group C** \\ \hline Deformation of the connecting screw. & 0 & 0 & 0 \\ \hline Deformation of the abutment. & 0 & 0 & 0 \\ \hline Fracture line or crack in the monolithic crown. & 10 & 10 & 10 \\ \hline Visible destruction of the adhesive bond between the monolithic crown and the abutment. & 10 & 10 & 10 \\ \hline Destruction of the monolithic crown or titanium abutment. & 10 & 10 & 10 \\ Any defragmentation of a sample was considered destruction. & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Analysis of test samples after compressive strength test. Figure 7: (**a–c**) Fracture pattern in different subgroups. (**a**) Group A1—the fracture was in the area of the tooth neck, horizontally and circumferentially. (**b**) The fracture line in all other subgroups was longitudinal and divided the permanent crown into two halves. (**c**) Diagram of fracture pattern. As each of the three groups was composed of five incisors and molars, the statistical analysis also aimed to investigate whether there were significant differences in the resistance of the materials in each group based on the tooth type. A series of \(t\)-tests were carried out for each of the three groups, wherein the incisor and molar scores were directly compared.