Stem cells have the ability to reproduce and differentiate into specialized cells. The document discusses various types of stem cells including embryonic, adult, dental, and induced pluripotent stem cells. It provides details on stem cell sources from oral and maxillofacial regions like dental pulp stem cells, stem cells from exfoliated deciduous teeth, and periodontal ligament stem cells. The document concludes that stem cell-based therapies show potential for repairing and regenerating tissues and that continued research may enable whole tooth regeneration.

1. STEM CELLS- REGENERATING HOPES
PRESENTEDTO
DR SEEMA CHAUDHARY
DR CHAITRATR
DR NAVEEN MANUJA
DR ASHISH SINHA
DEPARTMENT OF PEDIATRIC DENTISTRY
PRESENTED BY:
TABINDA KHAN

2. WHAT IS A STEM CELL?

3. A Stem Cell is a Cell from the embryo ,fetus or adult that has,
under certain conditions ,the ability to reproduce itself for long
periods.
In the case of adult stem cells , it has the potential to reproduce
through the life of an organism.
It can also give rise to specialized cells that makeup the
tissues and organs of the body.

5. Characteristics of Stem cells
1. Plasticity: Ability of stem Cells to convert from one lineage to
another is Plasticity. i.e Stem Cells from one particular tissue
can be programmed to produce cells of another tissue.
2. Self Renewal Capability:These Cells can undergo two types of
divisions
1.symmetrical division
2. Asymmetrical divisions
It ensures that stem cells populations last throughout the life of an
organism and do not become exhausted.

6. Pluripotency: It refers to “having more than one potential outcome .”
In stem cells it has the ability to produce cells/tissues from any of the
three germ layers (endoderm, mesoderm ,ectoderm) except
the extra embryonic tissues like placenta.
Clonality :These cells are genetically identical to their parent cell from
which they divide and have same precursor. Stem cells from embryo
and fetal tissues are clonally derived

7. TOTIPOTENT STEM CELLS Give rise to both embryo and placenta.They can form all tissues in
an organism or give rise to a complete organism.
PLURIPOTENT STEM CELLS Give rise to all three germ layers of the embryo i.e ectoderm,
mesoderm and endoderm but cannot from the placenta.
MULTIPOTENT STEM CELLS Give rise to tissues from one of the germ cell layers only .
MONOPOTENT STEM CELLS Give rise to cells from one lineage only like neural or skeletal
muscle cells.
DEVELOPMENTAL HIERACHY OFTHE STEM CELL

8. TYPES OF STEM CELLS
THE EMBRYONIC STEM CELLS
• A Research came in November 1998 led byThomson at the University of Wisconsin- Madison
who first developed a technique to isolate and grow the cells from Human Blastocysts
donated by couples undergoing treatment for infertility.
• The cells were sub cultured successively ,yet they retained their normal karyotypes.
PROPERTIES
• They are pluripotent cells
• They lack the G1 phase in the cell cycle and are mostly found in the S phase during which they
synthesize DNA.
• Embryonic stem cells are capable of undergoing an unlimited number of symmetrical
divisions. Hence ,retain karyotype after long time.

9. • Human Embryonic stem Cells do not appear to undergo replicative
senescence or ageing and therefore can expand continuously in
culture.
• These cells show high levels ofTelomerase activity, they can
thereby replace their telomeres and reset the replicative clock,
allowing continued divisions.

11. Adult stem cells are undifferentiated cell types found among differentiated cells in an
organ or tissue.
All specialised tissues with renewal capacity throughout life contains adult stem cells
which help replenish loss during normal senescence or tissue injury.
.
Roy et al,1999 were the first to isolate adult stem cell from the brain tissue,which could
differentiate into an oligodendrocyte and hence became the first to isolate a neural stem
cell.the most common known source ofASCs is bone marrow which contains both
hematopoietic stem cells (found in cord blood) and mesenchymal stem cells (found in
teeth).
ADULT STEM CELLS

12. PROPERTIES
• They possess the property of self renewal as they can proliferate for long
periods of time.
• They can give rise to mature cell types that have characteristics
morphologies and specialised functions.
• They possess plasticity as that of ESCs.
• First , committed stem and progenitor cells can be transplanted
autologously without immunologic consequences.
• As ASCs and progenitor cells are already determined or committed to cell
types for target organs ,they spontaneously differentiate under controlled
conditions in vitro into specific lineage cells, and have the ability to
reconstitute target organs in vivo.

14. STEM CELLS SOURCES FROM ORAL AND MAXILLOFACIAL
REGIONS
Dental stem cells forms an obscure population of self renewing cells with
potential utility in regenerating biologic components in human.
As tooth development is dependent on epithelial-mesenchymal cell
interactions ,dental stem cells are of two types:
EPITHELIAL STEM CELLS: which contribute to dental epithelial structures
like outer and inner dental epithelial cell layers ,stellate reticulum, stratum
intermedium, ameloblasts and enamel.
DENTAL MESENCHYMAL CELLS: which contribute to mesenchymally
derived tooth structures like the dental papilla, dental sac ,odontoblasts ,pre
dentin ,dentin, cementum, periodontal ligament and alveolar bone.

16. DENTAL MESENCHYMAL STEM CELL POPULATIONS
In HumanAdult teeth Dental Epithelial tissues are not capable of
self repair or renewal ,whereas Dental Mesenchymal tissues exhibit
such properties.
FIVE DIFFERENT HUMAN DENTAL STEM CELLSWHICH HAVE
BEEN ISOLATED AND CHARACTERIZED:
1. HumanAdult Dental pulp stem cell(DPSC)
2. Stem Cells from human Exfoliated Deciduous teeth(SHEDs)
3. Periodontal Ligament Stem Cell(PDLC)
4. Stem Cells fromApical Papilla(SCAP)
5. Dental Follicle Stem Cells(DFSC)

18. DENTAL PULP STEM CELLS
IN 2000 Dental Pulp Stem cells were discovered by a researcher at the National
Institutes of Health.
In around 2009 scientists from Italy announced the first ever human clinical
application using patients own dental stem cells to repair Mandibular defects.
In around 2011 a study showed that stem cells from teeth can create islet like cells
which produce insulin (a potential therapy for type 1 diabetes).
They are fibroblast like in morphology ,clonogenic, in nature and can maintain
their high proliferation rate even after extensive sub culturing.

19. For the first time Gronthos et al in 2002 isolated Human postnatal dental
pulp stem cells from Molar tooth of Adult patients.
These Cells were isolated using enzymatic digestion and colony forming
unit fibroblast assay.The cell within each colony presented a typical
fibroblast like morphology resembling those of bone marrow derived
mesenchymal stem cells.
They showed higher colony forming efficiency and cell proliferation in vitro
when compared to bone marrow derived mesenchymal stem cells.

21. STEM CELLS FROM HUMAN EXFOLIATEDTEETH(SHEDs)
Miura et al in 2003 isolated stem cells from Human exfoliated deciduous
teeth(SHED) of young patients, demonstrating similar characteristics to
postnatal dental pulp stem cells.
Their proliferative and clonogenic potential was even higher than those of
post natal dental pulp stem cells.
They can differentiate into neural cells, adipocytes, and odontoblasts.
The exfoliated teeth may be an unexpected unique resource for stem cell
therapies including autologous stem cell transplantation and tissue
engineering.

23. PERIODONTAL LIGAMENT STEM CELLS(PDLSCs)
The periodontal ligament is a specialized tissue located between the
cementum and the alveolar bone and has a role in the maintenance
and support of teeth.
Its continuous regeneration is thought to involve mesenchymal
progenitors arising from the dental follicle.
It was observed that PDL itself contains progenitors , which can be
activated to self renew and regenerate other tissues such as
cementum and alveolar bone.

25. STEMCELLS OF APICAL PAPILLA(SCAPs)
Stem cells from apical part of the human dental papilla have been
isolated .
This is a unique population of dental stem cells located at the tips of
growing tooth roots.
SCAPs have the capacity to differentiate into odontoblasts and
adipocytes.
SCAP can be easily accessible since they can be isolated from
human third molars.
They exhibit a higher proliferative rate and appears more effective
than pdl stem cells of tooth formation.

27. DENTAL FOLLICLE STEM CELLS(DFSC)
They have been isolated from follicle of human third molars and
express the stem cell markers Notch 1,STRO-1 positive.
DFSC can proliferate into cementoblasts in vitro and are able to form
cementum in vivo.
These cells, also known as dental follicle precursor cells or dental
follicle cells are multipotent stem cells and a potential source for
periodontal regeneration.

29. STEM CELLS FROM INFLAMED DENTAL PULP
Inflamed pulp which is discarded during pulp therapy procedures was observed
to be a potential source for harvesting adult stem cells.
Samples were processed In the laboratory including cell culture, isolation, and
differentiation into multiple lineages.
The results of analysis of various cell markers
(CD73,CD90,CD133,CD166,CD34,CD45) used for dental pulp was compared with
bone marrow .
The results showed an equal potency as bone marrow in harvesting cells.
The adult MSCs derived from inflamed pulp have been able to differentiate in
osteoblast, adipocytes, and chondrocytes.

30. INDUCED PLURIPOTENT STEM CELLS(IPS)
Researchers successfully derived ips cells from embryonic and adult mouse
fibroblasts through the ectopic co-expression of only four genes Oct 4,Sox2,Klf4
and c-Myc (Takahashi andYamanaka,2006)
Ips cells have been generated from different types of dental tissues/cells like
SHEDs, SCAPs, DFSCs., tooth germ progenitor cells, buccal mucosa fibroblasts
as they are easily accessible dental tissues and a promising source for cell
regeneration.
Use of IPS cells in regenerative medicine has advantages like they overcome
use of embryonic cells.
Their use eliminates issues related to graft rejection.
They provide an unlimited source of cells for clinical applications.

32. STEM CELL BASEDTHERAPIES
These therapies are used for repair and regeneration of
various tissues and organs .
These may provide alternate therapeutic solutions for a
number of diseases and in organ transplantations.

33. CHARACTERISTICS
1.They can be obtained from the patient itself.
2.They can proliferate in culture to produce large number of
cells from a limited source.
3.They can be easily manipulated to replace existing non-
functional genes using gene transfer methods.
4.They can be transferred to the diseased target tissues of the
host.
5.They can also amalgamate into host tissue and also interact
with the surrounding tissues.

34. Reconstruction of Dental and Craniofacial Structures.
The principal aims of Regenerative endodontics are to regenerate pulp like tissue
and pulp- dentin complex ,regenerate the damaged coronal dentin and to
regenerate the resorbed root, cervical or apical dentin.
There are two important facets namely tissue engineering and revascularization.
The revascularization of a root canal with necrotic pulp tissue is based on the
regenerative potential of the stem cells present in the periradicular tissue.
This method involves providing sterilized environment for growth of new tissue
from the tissue present in and around the tooth itself .
Mostly applicable in the immature permanent teeth leading to their continued
root formation.

35. Young et al in 2002 were successful in forming a complex dental structure for
the first time using porcine third molars.
Tooth shaped scaffolds were created using biodegradable polymers into
which the cellular mixtures were seeded then implanted in omentum, a
material rich in blood vessels to supply the developing tooth tissues with
nutrients and oxygen.
Surgical implantation was done in host mouse.
After 20-30 weeks tooth like structures were visible within the original
scaffolds.
Their shape and tissue organization resembled the crowns of natural teeth.
However bioengineered tooth was small and did not adjust to size and form of
the biodegradable scaffold.

38. Mesenchymal Stem Cell BasedTherapies in Head and
Neck region (Suzanne et al,2012)
1.Oral cancer
2.Cleft lip and palate
3.Maxillofacial trauma repair
4.Vocal fold injury
5.Skull based defects
6.Immunotherapy
7.Rhinoplasty
8.Vocal cord injury

41. Conclusion
Our understanding of the biological processes may serve asa future designand fabrication of
regeneratedteeth.
We have acquirednumerous somatic stemcells lines with higher plasticitythan what was
previously thought impossible.
We have moreover learned that missingcomponents of a morphogenetic field can be replacedby
similarcomponents from other tissues.
Future work will continue to explore the possibility of tooth tissue restoration in vivo and the
regeneration of whole tooth both in vivo and in vitro .
severalexperimental approaches to whole tooth replacementhave been designedandperformed
but they can all be consideredto belong in a single class of “teeth bioengineering”
Stem cell basedtechnology can be considereda safe and reliable approach.

42. THANK YOU