Inadequate bone quantity
is commonly encountered in implant dentistry,
often as a consequence of long standing tooth loss.
These defects can be of considerable size,
and often currently available techniques
can provide unpredictable treatment outcomes.
This means that novel methods are required,
and tissue engineering is one such technique.
Tissue Engineering is a multidisciplinary field,
which incorporates engineering, cellular molecular science,
and clinical specialties.
It involves the fabrication of tissues outside the body
for implantation into the body.
There are several essential components
of Tissue Engineer constructs.
These are, the presence of
appropriate numbers of responsive progenitor cells.
Furthermore, we require
the correct extracellular matrix or scaffold,
and finally, we need the appropriate levels
and sequence of regulatory signals.
In terms of the cell component,
immature and undifferentiated progenitors,
it means the stem cells
are ideal for tissue engineering
because of their favourable proliferative properties
and ability to differentiate into multiple cell types.
Furthermore, several important features
need to be considered in regards to scaffolds
for bone tissue engineering
The requirements for these scaffolds are,
the correct form, an ability to fill
complex three-dimensional bone defects.
We also need to consider the function and the ability
to provide temporary mechanical load bearing.
Fixation is also very important
in terms of achieving secure attachment,
task-eliminating motion.
And most importantly, we need to be able
to enhance bone formation
by providing appropriate mass transport environments,
allowing perfusion, and delivering osteoinductive factors,
including cells, proteins, and/or genes.
Providing an appropriate environment
for tissue engineering is essential
for the maturation of the scaffold
A suitable environment for tissue engineering
can be achieved by adding growth factors
and other extracellular matrix molecules
such as bone morphology proteins.
In this slide, we can see conceptually
how a tissue engineering construct
can be used to regenerate a major defect in the mandible,
which is a commonly encountered problem
in dental implantology.
The advantages of this approach
are that there is no need for autogenous grafting
and the associated morbidity of this procedure.
Furthermore, we have greater control
of the biological processes in vitro
and a mature construct can be implanted
in vivo with defined properties.
This is particular desirable where we want
to have controlled temporal and spatial maturation process
as well as when we want
to incorporate bio-elective molecules.
Finally, I would like to look into the future,
hopefully, not to far into the future
and present a clinically plausible approach
to making customized tissue engineered constructs.
We would commence by obtaining a precise image
of the bone defect.
This will be followed by the use
of a computer-assisted design
to make an accurate digital replica of the missing tissue,
and then bioprinting will be utilized to manufacture
and visualize construct that precisely replicates
the missing bone.
This construct would then be inserted into the patient.