The regenerative endodontic procedures (REPs) guidelines offer a valid clinical procedure proposing the use of a combination of antimicrobials and irrigants, no canal walls instrumentation, induced apical bleeding to form a blood clot and a tight seal into the root canal to promote healing. This procedure still presents a certain unpredictability. Drawbacks such as lack of real tissue regeneration and maintained signs or symptoms are to be described.
Three factors are needed to achieve upregulation of cellular synthesis and the formation of new tissue: A permissive environment, cells capable of secreting extracellular matrices and the release of molecular signals for cell interaction. Recent studies show that, statins, a family of lipid-lowering agents, have anti-inflammatory properties and suppress the progression of apical periodontitis. Simvastatin induces odontoblastic differentiation, inhibit osteoclast differentiation in periapical lesions and promotes calcified matrix formation.
Dental pulp stem cells (DPSC) may rebuild the lost pulp tissue in the canal and give rise to replacement odontoblasts for substituting the damaged primary ones, being totipotential stem cells.
For further investigation we propose to culture this cells exposing them to simvastatin (SIM) and apply them to an in vitro model of artificial pulp chamber (APC) in a group of a DPSC matrix with a SIM supplemented absorbable gelatin sponge, another of cultured blood with a SIM supplemented absorbable gelatin sponge above and a control group.
Testing the SIM infused cells for metabolic activity, ALP activity, calcium deposition, and cell migration helps to understand the action of simvastatin on them. Testing the three APC groups for Live/Dead assay, and different gene expressions by real-time polymerase chain reaction and mineralized matrix deposition is useful to understand how an absorbable gelatin sponge and simvastatin can improve the current REPs guidelines success rate and results.
The scope of this research is to prove that simvastatin can help risen the success rates of the already existing clinical procedure, by giving a better certainty of the quality of the tissue formed ad novo and lowering the chances of a relapse. If we can translate what we learn on a laboratory environment first in vitro and subsequently in vivo in order to include it in to a part of a clinical procedure, that can be performed on an everyday basis, with materials that are easily attainable for practitioners, it could make a difference for a big amount of patients from any background.