Severe tooth decay or trauma damages the tooth. The living
tissues that comprise the sensitive inner dental pulp become exposed
and vulnerable to harmful bacteria. Once infection takes hold, few
treatment options - primarily root canals or tooth extraction - are
available to alleviate the painful symptoms.
Researchers at Tufts University School of Dental Medicine (TUSDM)
now show that using a collagen-based biomaterial to deliver stem cells
inside damaged teeth can regenerate dental pulp-like tissues in animal
model experiments. The study, published online in the Journal of Dental Research
, supports the potential of this approach as part of a strategy for restoring natural tooth functionality.
‘Using a collagen-based biomaterial to deliver stem cells inside damaged teeth can regenerate dental pulp-like tissues in animal model experiments.’
"Endodontic treatment, such as a root canal, essentially kills a
once living tooth. It dries out over time, becomes brittle and can
crack, and eventually might have to be replaced with a prosthesis," said
senior study author Pamela Yelick, professor at TUSDM and director
of its Division of Craniofacial and Molecular Genetics. "Our findings
validate the potential of an alternative approach to endodontic
treatment, with the goal of regenerating a damaged tooth so that it
remains living and functions like any other normal tooth."
Yelick and her colleagues, including lead study author Arwa Khayat,
former graduate student in dental research at TUSDM, examined the safety
and efficacy of gelatin methacrylate (GelMA) - a low-cost hydrogel
derived from naturally occurring collagen - as a scaffold to support the
growth of new dental pulp tissue.
Using GelMA, the team encapsulated a
mix of human dental pulp stem cells - obtained from extracted wisdom
teeth - and endothelial cells, which accelerate cell growth. This mix was
delivered into isolated, previously damaged human tooth roots, which
were extracted from patients as part of unrelated clinical treatment and
sterilized of remaining living tissue. The roots were then implanted
and allowed to grow in a rodent animal model for up to eight weeks.
The researchers observed pulp-like tissue inside the once empty
tooth roots after two weeks. Increased cell growth and the formation of
blood vessels occurred after four weeks. At the eight-week mark,
pulp-like tissue filled the entire dental pulp space, complete with
highly organized blood vessels populated with red blood cells.
also observed the formation of cellular extensions and strong adhesion
into dentin - the hard, bony tissue that forms the bulk of a tooth. The
team saw no inflammation at the site of implantation, and found no
inflammatory cells inside implanted tooth roots, which verified the
biocompatibility of GelMA.
Control experiments, which involved empty tooth roots or tooth roots
with only GelMA and no encapsulated cells, showed significantly less
growth, unorganized blood vessel formation, and poor or nonexistent
The results support GelMA-encapsulated human dental stem cells and
umbilical vein endothelial cells as part of a promising strategy to
restore normal tooth function, according to the study authors. However,
they note that the current study was limited to partial tooth roots and
did not examine nerve formation in regenerated dental pulp tissue. They
emphasize the need for additional safety and efficacy studies in larger
animal models before human clinical trials can be considered.
"A significant amount of work remains to be done, but if we can
extend and validate our findings in additional experimental models, this
approach could become a clinically relevant therapy in the future,"
said Yelick, who is also a member of the Cell, Molecular &
Developmental Biology; Genetics; and Pharmacology & Experimental
Therapeutics programs at the Sackler School of Graduate Biomedical
Sciences at Tufts. "Our work is early stage, but we are excited for the
possibility of someday giving patients the option of regenerating their