Advances in treatment of tooth injury have shown that tooth regeneration from the pulp was a viable alternative of root canal therapy.  In this study, we demonstrated that Gutta-percha, nanocomposites primarily used for obturation of the canal, are not cutotoxic and can induce differentiation of dental pulp stem cells (DPSC) in the absence of soluble mediators.  Flat scaffolds were obtained by spin coating Si wafers with three Gutta-percha compounds: GuttaCore^TM, ProTaper^TM, and Lexicon^TM.  The images of annealed surfaces showed that the nanoparticles were encapsulated, forming surfaces with root mean square (RMS) roughness of 136-211 nm.  Then, by culturing DPSC on these substrates we found that after some initial difficulty in adhesion, confluent tissues were formed after 21 days.  Imaging of the polyisoprene (PI) surfaces showed that biomineral deposition only occured when dexamethasone was present in the media.  Spectra obtained from the minerals was consistent with that of hydroxyapatite (HA).  In contrast, HA deposition was observed on all Gutta-percha scaffolds regardless of the presence or absence of dexamethasone, implying that surface roughness may be an enabling fator in the differentiation process.  These results indicate that Gutta-percha nanocomposites may be good candidates for pulp regeneration therapy.

*Zhang L, Yu Y, Joubert C, Bruder G, Liu Y, Chang C, Simon S, Walker S, Rafailovich M. Polymers 2016; 8:193