## 4 Discussion  
In this study, the absorption of X-rays in mandibular tissues was analyzed comparatively utilizing both real tissues and tissue-equivalent materials [16; 27; 28]. The results revealed significant differences in X-ray absorption depending on the energy level both in the real tissues and tissue-equivalent materials [29; 30; 31]. For the skin tissue and PMMA, a significant difference in low-energy X-ray absorption was observed [32; 33]. At the 50 keV energy level, the skin tissue absorbed approximately 20.6% more X-rays than the PMMA, but this difference decreased to 4.7% as the energy increased. This finding indicates that higher energy X-rays are absorbed more similarly by both real tissues and tissue-equivalent materials [27; 34; 35]. PMMA, however, does not fully represent skin tissue in low-energy settings [36; 37]. Similarly, in the comparison between the parotid gland and PMMA, it was found that at 50 keV the parotid gland absorbed 13.2% more X-rays than the PMMA. This difference decreased to 4.6% at 100 keV. These findings suggest that biological tissues tend to absorb more low-energy X-rays, while the differences diminish as the energy levels rise [9; 38]. A similar trend was observed in the SMAS tissue, where low-energy X-rays resulted in a 22.5% higher absorption but this difference decreased at higher energy levels. These results highlight that tissue-equivalent materials may not fully represent real tissues, especially in low-energy radiation applications [39; 40]. In the comparison between the masseter muscle tissue and Parylene N, significant differences were observed. At low energy levels, the masseter muscle absorbed 50.2% more X-rays than the Parylene N. At higher energy levels, this difference further increased to 82.5%. These findings indicate that tissue-equivalent materials like Parylene N are inadequate for simulating dense muscle tissues. Therefore, more appropriate materials should be used to accurately represent such dense tissues [41; 42; 43]. In the comparison between buccal fat tissue and polyethylene, the differences were less significant. At the 50 keV energy level, the buccal fat tissue absorbed 1.7% more X-rays than the polyethylene. However, at higher energy levels, this difference increased to 5.3%. These results suggest that polyethylene is a suitable material for simulating buccal fat tissue, although the gap widens as the energy levels increase. The literature also supports the use of polyethylene for simulating fat tissues [44; 45]. In the comparison between mucosa tissue and PMMA, low-energy X-rays caused the mucosa tissue to absorb 16.7% more X-rays than the PMMA. This difference increased to 63.3% at higher energy levels. This finding underscores the importance of careful consideration when simulating mucosal tissues with tissue-equivalent materials. In the comparison between saliva and water, a 5.8% difference was observed at the 50 keV energy level, but this increased to 40.7% at higher energies [46; 47; 48]. For the gum tissue and PMMA, a 20.8% difference was observed at 50 keV, which increased to 50.1% at 100 keV. Larger differences were found in the comparisons between the cortical and cancellous bone tissues and Teflon. For the cortical bone and Teflon, a 51.8% difference was observed with low-energy X-rays and this increased to 70.1% at higher energies. Similarly, in the cancellous bone, the difference ranged between 63.5% and 75.1% [49]. The findings of this study demonstrate that tissue-equivalent materials may not fully simulate real tissues, especially in low-energy X-ray applications. The materials used for simulating soft tissues and muscle tissues do not accurately represent real tissues, particularly in low-energy X-rays. This can lead to significant issues in medical imaging and radiation dose calculations. The safety of X-ray exposure is closely related to the energy levels used.