Introduction: Stem cells are the body's natural reservoirs to replace damaged specialized and non-specialized cells. These cells have a very high potential and have the ability to transform and differentiate into most or we can say all the cells and tissues of the body. Stem cells with their differentiation can become cells. including muscles, red blood cells, brain cells, etc.
Here, we want to examine a sample of mesenchymal stem cells, which are an important population of multipotent stem cells with high growth and recovery capabilities. These cells can differentiate into all the cell lines that are the basis of mesenchyme or connective tissue and cause the repair or regeneration of such tissues. Also, as mentioned, these cells retain the characteristics of stem cells and tissue regeneration capacity. These findings suggest that periodontal ligament stem cells may be used to create a biological root that can be used in a similar way to metal implants.
According to the findings and tests, it was found that even the teeth have a reserve of stem cells that are found in both milk and permanent teeth. These cells have the ability to fully regenerate themselves. Due to their compatibility with the body's immune system, these cells can be used in many fields of medical science. Pulp cells of human deciduous teeth show high proliferation and differentiation ability, and by differentiating these cells into pseudo-odontoblast and osteoblast cells, it is possible to help rebuild the lost structure of the tooth. Different methods can be used to track cells.
This growth, due to the recognition of the potential of stem cells, led to surprising results, such as the possibility of rejection of the transplant after the transplantation of these cells is less, and there is no need to use immunosuppressive drugs. Of course, in relation to the potential of mesenchymal cells of children and adults, it can be mentioned that according to the clinical features of the pulp of children's milk teeth, it was observed that these cells have a high proliferation and differentiation ability compared to the pulp cells of adults. Attention to the many results obtained can be found that the use of mesenchymal cells from children's milk teeth leads to greater efficiency, and these cells can be differentiated into a complete set of teeth after growth and passage in a laboratory environment, as well as determining the number of dental canals by using the expression of affected genes find.
Methods: Investigation in 18-25 year olds 14 samples from the pulp and 6 samples from the dental follicle of the third molar of adults between 18 and 25 years old were collected. The collected samples were extracted due to impaction or orthodontic treatment with expert diagnosis and with the prior consent of the patients. These teeth had no caries or previous restorations, and the patients were all healthy and did not have any systemic disease.After being drawn into the tubes containing Gibco, RPMI 1640, containing 2x antibiotics (2 times the strength of penicillin and streptomycin, Gibco), the tooth samples were transferred to the molecular cell laboratory at a temperature of 4 degrees Celsius, and to reveal the pulp chamber of the teeth. , were cut from the enamel-cement connection by carbide disc and handpiece. And after that, the pulp was separated from the teeth, from the pulp chamber by means of a fine file; Then, for cell culture of the pulp tissue and follicle, these cells were divided into smaller pieces by surgical blade number 10, and then they were placed in Falcon containing 4 mg/ml collagen type (sigma I) solution, 104 mg/ml Dispase solution (Gibco) with a ratio of 1.1 was placed for 45 minutes at a temperature of 37 degrees Celsius After that, they were added to the culture medium and centrifuged at 600 g for 10 minutes. The resulting cell plates were cultured with mixed culture medium and after being transferred to the appropriate zvt in an incubator with a temperature of 37 degrees Celsius, 5 atmospheres and 2% CO2.
This culture medium was changed every two days until 70% of the bottom of the plate was filled with cells. When the bottom of the plate reached 70%, the samples were passaged with the help of trypsin-EDTA. And finally, flow cytometry analysis was used to investigate the phenotypic profile of surface markers and the nature of stem cells from the pulp and follicular tissue of the third molar tooth. For this purpose, the cells were suspended in one milliliter of PBS (Phosphate Buffer Saline) in the third passage of trypsin. They were placed with a concentration of 1,000,000.
Then the cells were divided into 6 tubes and 5µI of antibody was added to each PE tube and the tubes were then placed in a dark environment at 4°C for 30 minutes and after this period the cells were washed with 1ml of washing buffer. and centrifuged at 1200 MPR for 5 minutes, after which each cell sample was suspended in 300 µl to 500 µl washing buffer and analyzed by flow cytometry.
Results: According to the mentioned cases, it can be said that there are mesenchymal stem cells of the dental pulp in the mature cells of the adult because after a dental injury, the dental pulp undergoes dentination in order to repair the damaged area by building and depositing the dentin matrix. This repair process takes place throughout a person's life, which indicates the presence of mesenchymal cells in the dental pulp of adults and the ability to create odontoblasts under the influence of appropriate signals، But in general, the potential of adult stem cells is not as much as that of fetal and childhood stem cells, for this reason, it is better to extract or use embryonic tooth root mesenchymal cells (from the gums, especially the posterior gums) for the reconstruction and repair of teeth. From the mesenchymal stem cells of milk teeth, these cells, as mentioned, are not limited to any category and age group, and even the ability to donate these cells from one person to another is possible, and the condition of donating teeth:The complete genomic and systematic health of the donor person, with this work, even in adults who often have lost their milk teeth (except for latent milk teeth), the gene of mesenchymal stem cells of children or fetuses can be used to repair and regenerate teeth do .
In the laboratory method, mesenchymal stem cells in adults, although they have the possibility of repair or regeneration, but after they are separated from the patient, they must first go to the laboratory environment, and after their amplification and differentiation, they are injected into another person as an allograft or xenograft recipient, but with Paying attention to the many problems that may arise during the strengthening, injection, long time and potential and less adaptation of these cells, such as early tooth decay, tooth loss, immune system attack on these cells through immune response, etc.
In this regard, it can be said that the use of a secondary method (experiment: laboratory cultivation of mesenchymal cells of milk teeth) is more effective and efficient in this field. And due to the problem-causing factors that exist in adult mesenchymal cells, this ideal protocol for humans is relatively far away from its application. Recently, with the discovery of a gene called DIK1, with the discovery of a gene called DIK1, it is possible to learn about the activation of stem cells and tissue regeneration in teeth repair and to undergo a shorter treatment period in tooth repair using stem cells. (restoration and reconstruction of teeth have gone through a relatively long period)
With the activation of stem cells, these cells can send messages to the main cells that help to activate the repair and reinforcement cells (this is also possible by using low power lasers) as a result of these cells forming dentin. the( hard tissue of the tooth) helps a lot.
Conclusion: Therefore, it can be said that tooth regrowth is a reality, not an ideal, and considering that the tooth is made up of two different types of tissue, logically, making a tooth requires communication and cooperation with epithelial cells and odontogenic mesenchyme. The recombination of epithelial tissue and dental mesenchyme to create teeth both in the laboratory and in the living environment leads to the fact that the combined cells can organize and form individual layers and are also able to differentiate into odontoblasts and amyloblasts.
In order to make a complete tooth that has enamel and dentin, epithelial and mesenchymal cells are respectively introduced into the collagen gel solution and then implanted inside the oral cavity, and with this technique, the presence of all dental structures such as odontoblasts, amyloplast, pulp, Blood vessels, crown, root, periodontal ligament and alveolar bone can be seen, so the implantation of this dental mass (mesenchyme + epithelial cells) leads to the development of maturity and regrowth of teeth.
So, it can be said that by using engineering and modern methods, mesenchymal stem cells extracted from the pulp of mature teeth and milk teeth can be used to repair dental tissues, especially sub-tissues that have mesenchyme and connective tissue, and with this Humans at any age are able to re-grow their teeth using the mesenchymal stem cell gene, and it is worth noting that the use of the mesenchymal gene is not restricted from one person to another (no age limit) and one of the challenges which makes this different from other methods: the use of this method, if the mesenchyme gene used is healthy, unlike the implant, does not have any limitations or harm، And replacing this method instead of today's methods, dentists can use it more economically and optimally.