The laser stimulates the restoration of teeth
Harvard University researchers working under the guidance of Professor David Mooney have demonstrated the ability of low–power light radiation to stimulate dental stem cells to regenerate dentin, a type of bone tissue that forms the tooth body. Moreover, they described the molecular mechanism involved in this process and reproduced the results obtained in experiments on several laboratory and animal models.
Differentiation of stem cells into cells of different types can be triggered by various biologically active molecules, including regulatory proteins known as growth factors. Existing methods of regenerative medicine imply the isolation of stem cells from the body, carrying out certain manipulations on them in the laboratory and returning back to the body. The introduction of such approaches into clinical practice is hampered by a number of regulatory and technical difficulties.
At the same time, according to Mooney, the method developed by his group does not imply the introduction of anything new into the body; moreover, laser radiation is widely used in medicine, including dentistry. Therefore, there should be no serious obstacles on his way to clinical practice.
At the initial stage of work, holes were drilled in the molars of rats, through which the pulp of teeth containing stem cells was exposed to low-power laser radiation. After that, the holes were covered with temporary fillings, leaving a cavity formed during drilling of the tooth. The X-ray and microscopic examination carried out after 12 months confirmed the fact of enhanced dentin formation caused by laser radiation.
Images obtained by microscopy of tissue sections stained with two different dyes 12 weeks after laser treatment of dental pulp. Yellow # symbols are applied to areas of newly formed (tertiary) dentin. In the teeth treated with laser radiation, the amount of new dentin is greater than in the teeth of mice of the control group.At the next stage, the researchers conducted a series of experiments on cell cultures, which allowed them to identify the molecular mechanisms that provided the regenerative effect of laser radiation.
It turned out that the main role in starting the process of dentin formation by stem cells belongs to the transforming growth factor beta-1 (TGF-beta1), a regulatory protein found everywhere in the body.
The authors demonstrated that laser radiation triggers the so-called domino effect. First, there is a dose–dependent induction of the formation of reactive oxygen species (ROS) - chemically active molecules that play an important role in the functioning of cells, which, in turn, stimulate the transition of transforming growth factor beta-1 from the latent form to the active one. The end result of this is the differentiation of stem cells and the formation of dentin.
Laser radiation has been used in medicine since the late 1960s. It is actively used in cosmetology for cauterization of benign skin neoplasms and removal of unwanted hair. However, doctors periodically report observations according to which low-power laser radiation can stimulate various biological processes, including skin rejuvenation and hair growth. However, until now, the clinical effects of such exposure have not had convincing evidence. For the first time, the authors were able to reveal the underlying processes at the molecular level, thereby laying the foundation for the development of new approaches to dental treatment.
Currently, they are developing safety and efficacy parameters necessary for planning and conducting clinical trials of a new method. The researchers also believe that their observations indicate the expediency of conducting further research on the possibility of using laser radiation in other areas of regenerative medicine.
Article by P. R. Arany et al. Photoactivation of Endogenous Latent Transforming Growth Factor-1 Directs Dental Stem Cell Differentiation for Regeneration is published in the journal Science Translational Medicine.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on materials from Harvard University:
Researchers use light to coax stem cells to repair teeth.
Portal "Eternal youth" http://vechnayamolodost.ru02.06.2014