An ultrastructural investigation of tissue-engineered pulp constructs implanted within endodontically treated teeth

Background. The authors conducted an ultrastructural scanning electron microscopic (SEM) investigation of tissue-engineered pulp implanted within endodontically treated teeth. Methods. Stem cells from human exfoliated deciduous teeth were seeded on a synthetic open-cell D,D-L,L-polylactic acid scaffold with or without the addition of bone morphogenic protein-2 and transforming growth factor beta 1 to create pulp tissue constructs. The pulp constructs were implanted into 105 extracted human premolar teeth with a single root canal that had been cleaned and shaped by using rotary instrumentation in a crown-down manner to ISO size no. 35. Results. An ultrastructural examination of the SEM micrographs at x2,000 magnification revealed cell adherence within all of the pulp constructs, with little difference between the scaffold types or with the addition of growth factors. Conclusions. These results support the proof-of-concept that it is possible to implant tissue-engineered pulp constructs into teeth after cleaning and shaping. Clinical implications. Future regenerative endodontic treatment may involve the cleaning and shaping of root canals followed by the implantation of vital dental pulp tissue constructs created in the laboratory.