# Regenerative Endodontics as the Future Treatment of Immutative Permanent Teeth
## 3 Results
### Components of the Pulp Regeneration Process  
A prerequisite for pulp regeneration is the supply of its essential components: stem cells, growth factors, and scaffolds to the canal lumen [8]. Dental stem cells, which are an example of mesenchymal stem cells (MSCs), are found in the dental pulp, dental papilla, periodontium, and periapical region. Many types are identified, which show a high multilinear proliferative potential and the ability to differentiate into cells involved in REP [68; 69; 70; 71] (Table 1). Growth factors, isolated from platelets, plasma, dental tubules, dental papilla, and the periapical region of the root, are bioactive proteins that act as signaling and regulatory factors. By binding to cell receptors, they influence a number of interactions between the cells and the extracellular matrix (ECM). In addition, they act as regulators of migration, differentiation, cell proliferation, and tissue formation [72; 11; 73; 74; 75; 76; 11] (Table 2). The scaffold creates a suitable environment for the processes mentioned above and provides support for the emerging new tissue [16]. An ideal carrier should show biocompatibility, biodegradability, no cytotoxicity or inflammation induction, adequate porosity, and pore size [9; 54]. In regenerative endodontics, the fibers present in blood clot (BC), platelet-rich plasma (PRP), and platelet-rich fibrin (PRF) are employed as a standard scaffold [11]. Reports in which other scaffolds were used are available in the literature, and knowledge on this subject is developing rapidly [77; 78; 79; 80; 81; 82; 83; 84; 85] (Table 3). The simplest way to obtain a scaffold in the root canal is to induce bleeding from the periapical region, which causes blood to flow into the canal and form a clot. Its main ingredient is fiber, which plays a key role in the formation of new connective tissue. Stem cells from the periapical region of the root also enter the canal along with the blood. However, BC contains few growth factors [18]. Moreover, the procedure requires using an anesthetic without vasoconstretrics, which may be associated with pain during the induction of bleeding. Excessive instrumentation of the periapical region also poses the risk of damaging [PERSON]'s sheath, resulting in root growth inhibition and procedure failure [86]. In some cases, it can be problematic to obtain sufficient bleeding from the periapical region [87]. In addition, a study by [PERSON] et al. [88] found that greater crown discoloration and smaller root growth in length and thickness were observed with BC than PRE. \begin{table}
\begin{tabular}{c c} \hline
\begin{tabular}{c} Differentiation toward odontoblasts \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Stem cells involved in apexogenesis and REP. \begin{table}
\begin{tabular}{c c} \hline
**Type** & **Function** \\ \hline \hline \
\begin{tabular}{c} Bone Morphogenetic Protein (BMP) \\ Vascular Endothelial Growth Factor (VEGF) \\ IGF Insulin-like Growth Factor (IGF) \\ TGF-\(\beta\) Transforming Growth Factor-\(\beta\) (TGF-\(\beta\)) \\ FGF Fibroblast Growth Factor (FGF) \\ Platelet-Derived Growth Factor (PDGF) \\ \end{tabular} &
\begin{tabular}{c} Dentinogenesis \\ Proliferation, angiogenesis \\ Proliferation \\ Migration, proliferation \\ Migration, proliferation, dentinogenesis \\ Migration, angiogenesis \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Growth factors involved in apexogenesis and REP.  
PRP, the platelet concentrate obtained from patient plasma, acts as both a scaffold and a rich reservoir of cytokines and growth factors released from platelet \(\alpha\) granules [89]. PRF is a newer substance, a so-called second-generation platelet concentrate, containing a fibrin membrane enriched in platelets, growth factors, and cytokines [90].