## 4 Discussion  
[PERSON] et al. [6] investigated the bending quality of provisional bridge structures made on the same matrix but using different materials--conventional ones like PMMAs and composites, as well as PMMA discs manufactured via CAD/CAM technology. They found better maximum fracture force (Fmax) indicators for CAD/CAM PMMAs compared to conventionally made PMMAs, which is confirmed by the data from our laboratory study. In conclusion, the authors mention that, due to the clear advantages of composite materials over PMMAs, it is necessary to develop composite blanks for CAD/CAM milling of provisional structures. This could lead to an improvement in the quality and efficiency of dental constructions, while utilizing more modern and advanced materials and technologies. In a laboratory study from 2014, [PERSON] et al. [30] compared the bending strength of experimental bodies according to ISO 10477 and the marginal accuracy of provisional crowns made from clinical composite materials for provisional structures with CAD/CAM PMMA (Teilo CAD) and composite material (VITA CAD-Temp). As a result of the investigation, the authors noted the best bending strength indicators for the CAD/CAM PMMA material and the lowest for the composite CAD/CAM material, while digitally fabricated ones exhibited better accuracy. These results, as indicated by the authors, have been confirmed by our laboratory study [30]. [PERSON] et al. [32] compared the physical and mechanical qualities (color stability, water absorption, wear resistance, surface hardness, fracture resistance, and microleakage) of CAM-milled crowns made from PMMA with conventional materials for the manual fabrication of provisional structures. The authors found that milled crowns outperformed those made from manual fabrication materials in all aspects except microleakage (where staining does not penetrate any experimental body). They came to the conclusion that CAD/CAM-produced provisional structures exhibited stable physical and mechanical qualities and could be used for long-term provisional constructions. Our results support [PERSON] et al. 's conclusions [32]. [PERSON] et al. [33] conducted a laboratory study on the bending strength of experimental bodies according to ISO 10477 using five materials for provisional structures: three CAD/CAM PMMA blanks, one composite, and one conventional PMMA. The authors concluded that the experimental bodies made from CAD/CAM PMMA materials demonstrated higher bending strength values than the composite material, which in turn exhibited higher values than the conventional PMMA. This ranking of materials was confirmed by the data obtained in our laboratory study. In a similar laboratory investigation, [PERSON] et al. [35] examined the bending strength, impact strength, and modulus of elasticity of experimental bodies according to ISO 20795 using two types of CAD/CAM PMMAs and one conventional PMMA. Although the study focused on PMMAs for removable prosthodontics, the results align with those of our laboratory study, indicating that subtractive milling methods for pre-cross-linked polymerized PMMAs exhibit the highest mechanical qualities [35]. [PERSON] et al. [36] conducted a comparative study between materials for additive and subtractive CAD/CAM provisional prosthodontics. They compared provisional bridge structures made from a single CAD model using CAM milling from PMMAs and 3D printing via rapid prototyping technology. The subtractively manufactured experimental structures exhibited higher values in bending strength tests, which is consistent with the findings of our laboratory investigations. In a laboratory study from 2022, [PERSON] et al. [26] compared the compressive strength and bending strength of test specimens made from materials for provisional non-permanent prosthodontics--self-polymerizing PMMA, heat-polymerizing PMMA, and a composite resin for DLP (digital light processing) 3D printing.