## 4 Discussion
Gene expression determination of Cu, Zn-SOD, and Mn-SOD isoenzymes in irreversibly symptomatic and inflamed pulp samples from permanent teeth revealed statistically significant elevated levels in the cases of irreversible pulpitis [28]. Although [PERSON] et al. [29] do not mention the type of inflammation of the permanent dental pulp samples used in their study, our results are similar to the data they presented, regarding statistically significant elevated levels (\(p=0.0001\)) of Cu, Zn-SOD observed in inflamed pulp specimens compared to the controls. The data obtained in our research are also in accordance with the results of a study by [PERSON] et al. [30], who highlighted statistically significant elevated levels of SOD in permanent teeth with irreversible inflammation versus healthy pulp tissues. [PERSON] et al. [31] focused on the total activity of SOD in irreversibly inflamed (no mention if symptomatic or asymptomatic) and healthy pulp samples obtained from the permanent teeth of adolescents, the differences between the two groups not being statistically significant. A study by [PERSON] et al. [32] presented results that contradicted with the data obtained by our research team, as their results displayed statistically significant elevated levels (\(p<0.00\)) of Cu, Zn-SOD activity, using spectrophotometric methods, in the control group versus clinically healthy and symptomatic human dental pulp samples from permanent teeth. As we mentioned in our previous study, the advanced pulp pathology and progression of inflammation, which may cause destruction of the enzyme, and the different methods used to test the presence of the biomarker, may have contributed to these different results. Our results are also in accordance with the results of [PERSON] et al. [33], who observed statistically significant augmented levels of TGF-\(\beta 1\) in permanent teeth with irreversible pulp inflammation, with spontaneous and prolonged episodes of pain versus healthy dental pulp samples. TGF-\(\beta 1\) is a multifunctional cytokine and angiogenic growth factor, and its effects are dependent upon the types of target cells and local concentrations [34]. It is also a potent immunosuppression, and it may have a crucial role in the dentine-pulp complex reparative process as it can trigger matrix secretion and formation of type I collagen [35]. It is supposed that TGF-\(\beta 1\) is sequestered in the dentine matrix and released during carious processes and reparation mechanisms, such as reparative dentinogenesis [33,36]. Various studies showed that TGF-\(\beta 1\) can regulate matrix turnover and may stimulate growth and differentiation of pulp cells when used as pulp capping material [36,37]. A multiplex assay was used by [PERSON] et al. [8] to analyze osteoclastin levels in pulp samples with irreversible inflammation versus healthy pulp specimens from permanent teeth, revealing statistically significant elevated levels in the inflamed pulp group (\(p<0.05\)), the results being parallel to ours. Mature osteoblasts secrete osteoclastin their latest differentiation stage [38,39]. Osteocalcin, a non-collagenous protein, is expressed in mature odontoblasts that form the new matrix of reactionary dentine, as demonstrated by [PERSON] et al. [40]. Osteocalcin levels are increased after bone fractures and may remain elevated during tissue healing, with an important role in bone reparation [41,42]. Macrophages are the dominant inflammatory cells in pulp inflammation and express osteoclastin in their terminal differentiations to osteoblasts [8]. One of the limitations of our study is represented by the small number of samples. Unfortunately, the COVID-19 pandemic also attributed to a negative impact in the research field; thus, our access to patients was limited as the academic activity was limited to online courses for a long period of time and all dental treatments were postponed.