STEM CELLS

Repair and Regeneration of Oral Tissues

What are Stem Cells?• Stem cells are a class of undifferentiated cells that

are able to differentiate into specialized cell types. Commonly, stem cells come from two main sources:

• Embryos formed during the blastocyst phase of embryological development (embryonic stem cells) and

• Adult tissue Both types are generally characterized by their

potency, or potential to differentiate into different cell types (such as skin, muscle, bone, etc.).

Sources :

•Blood of the umbilical cord•Adipose tissues•Brain•Skin•Intestine•Bone marrow•Different parts of tooth ; the dental pulp,

root apical papilla, tooth germs

Properties :

•Stem cells are capable of cell renewal•They have the potential to differentiate

along different cell lineages that include adipogenic, cementogenic, neurognic, osteogenic, and chondrogrnic cells

Organ and tissue regeneration

•Tissue regeneration is probably the most important possible application of stem cell research. Stem cells could potentially be used to grow a particular type of tissue or organ if directed to differentiate in a certain way. Stem cells that lie just beneath the skin, for example, have been used to engineer new skin tissue that can be grafted on to burn victims.

•TISSUE ENGINEERING : It focuses on the fabrication of new

tissues to replace damaged tissues and provides new horizons for periodontal regeneration.

•GENE THERAPY : Gene transfer, which is insertion of a

transgene into a host cell to achieve expression of periodontal cell activity and regeneration capacity.

•IMPLANTOLOGY : Implantology have focused on creating

new generation of bioactive surfaces for improving the integration, stability, and ensure clinical performances of implant.

Mechanism of repair in oral tissues :

• The absence of ameloblasts prevents the repair of enamel.

• Dentine is capable of repair with basic mechanisms, but scar tissues that forms become mineralized.

• The repair of dental supportive tissues depends on the degree of damage.

• Oral mucosa has many similarities to skin and uses the same principle of repair, wounds of oral mucosa, especially the gingiva often heals without the formation of scar tissues.