RESUMEN
INTRODUCTION: Endodontic therapy is often complicated and technically demanding. The aim of this study was to develop a reproducible biomimetic root canal model for pre-clinical and postgraduate endodontic training. MATERIAL AND METHODS: A specific ceramic shaping technique (3D printing and slip casting of a root canal mould) was developed to reproduce canal systems with the desired shape and complexity using a microporous hydroxyapatite (HAp)-based matrix. The microstructural morphology, pore size and porosity, as well as the Vickers microhardness of the ceramic simulators (CS) were assessed and were compared with natural dentin and commercial resin blocks. The reproducibility of the root canal shapes was assessed using the Dice-Sørensen similarity index. Endodontic treatments, from refitting the access cavity to obturation, were performed on the CS. Each step was controlled by radiography. RESULTS: Many properties of the CS were similar to those of natural dental roots, including the mineral component (HAp), porosity (20%, porous CS), pore size (3.4 ± 2.6 µm) and hardness (120.3 ± 18.4 HV). DISCUSSION: We showed that it is possible to reproduce the radio-opacity of a tooth and variations in root canal morphology. The endodontic treatments confirmed that the CS provided good tactile sensation during instrumentation and displayed suitable radiological behaviour. CONCLUSIONS: This novel anatomic root canal simulator is well suited for training undergraduate and postgraduate students in endodontic procedures.
Asunto(s)
Cavidad Pulpar/anatomía & histología , Endodoncia/educación , Modelos Anatómicos , Entrenamiento Simulado , Cerámica , Impresión TridimensionalRESUMEN
The arrangement of cells within a tissue plays an essential role in organogenesis, including tooth development. Progress is being made to regenerate teeth by reassociating dissociated embryonic dental cells and implanting them in vivo. In the present study, we tested the hanging drop method to study mixed epithelial-mesenchymal cell reorganization in a liquid instead of semisolid medium to see whether it could lead to tooth histogenesis and organogenesis. This method allowed the control of the proportion and number of cells to be used, and the forming microtissues showed homogeneous size. The liquid environment favored cell migrations as compared with collagen gels. Three protocols were compared. The one that sequentially combined the hanging drop and semisolid medium cultures prior to in vivo implantation gave the best results. Indeed, after implantation, teeth developed, showing a well-formed crown, mineralization of dentin and enamel, and the initiation of root formation. Vascularization and the cellular heterogeneity in the mesenchyme were similar to what was observed in developing molars. Finally, after coimplantation with a trigeminal ganglion, the dental mesenchyme, including the odontoblast layer, became innervated. The real advantage of this technique is the small number of cells required to make a tooth. This experimental model can be employed to study the development, physiology, metabolism, or toxicology in forming teeth and test other cell sources.