A critical analysis of research methods and biological experimental models to study pulp regeneration

Abstract

With advances in knowledge and treatment options, pulp regeneration is now a clear objective in clinical dental practice. For this purpose, many methodologies have been developed in attempts to address the putative questions raised both in research and in clinical practice. In the first part of this review, laboratory‐based methods will be presented, analysing the advantages, disadvantages, and benefits of cell culture methodologies and ectopic/semiorthotopic animal studies. This will also demonstrate the need for alignment between two‐dimensional and three‐dimensional laboratory techniques to accomplish the range of objectives in terms of cell responses and tissue differentiation. The second part will cover observations relating to orthotopic animal studies, describing the current models used for this purpose and how they contribute to the translation of regenerative techniques to the clinic.

Engineering a Microphysiological Model for Regenerative Endodontic Studies

“…In order to address these challenges, various 3D systems have been devised. One approach involves employing progenitor cells seeded within 3D scaffolds typically crafted from tooth crown slices [16]. However, this method is expensive, has limited scalability, and relies on the availability of human samples.…”

“…However, this method is expensive, has limited scalability, and relies on the availability of human samples. Alternatively, researchers have utilized cell perfusion chambers and other microfluidic devices to reconstruct the dentine-pulp interface, offering cost-effectiveness, although they do not fully capture the intricate 3D geometry of root canals [16].…”

“…The spatial organization of cells cultured in three-dimensional (3D) structures affects cellular behavior such as proliferation and migration [15]. In the field of endodontics, different devices have been developed for conducting three-dimensional cultures, including the use of dentin discs, organoid-based reconstruction strategies, diffusion chambers, and other animal models, but, independent of the system, there are difficulties in the translation to human models [16]. On the other hand, in vivo experiments can be cost-prohibitive, have low throughput, and require highly specialized personnel [17].…”

Cell Engineering Potential in Regenerative Endodontics

“…Of particular concern is the observed short survival span of implanted MSCs. 64 Transplantation of MSCs into inflamed tissue has demonstrated a reduced likelihood of their survival, with a significant decrease of implanted MSCs within the initial 24 hours. 65 These challenges underscore the imperative for further exploration and refinement of strategies to optimize the isolation, proliferation, and survival of MSCs in Cell-based REPs, aiming to enhance the overall efficacy of regenerative therapies.…”

Fluid flow-induced modulation of viability and osteodifferentiation of periodontal ligament stem cell spheroids-on-chip

“…Specifically, the inclusion of fluid flow, cellcell, and cell-matrix interactions within the experimental setup is widely acknowledged to provide enhanced physiological relevance. 19,20 Hence, applying fluid flow within in vitro cultures, which in turn provides fluid shear stress-induced mechanotransduction would enable partial emulation of native physiology of the PDL compared to static cultures. Studies on the incorporation of active fluid flow over monolayer-cultured PDL cells have demonstrated the impact of fluid shear stress on the rearrangement of cytoskeletal proteins, 21,22 modulation of tissue remodeling, 21 and immunoregulatory properties, 23 and production of growth factors, messenger molecules, and chemokines.…”