Vital pulp therapy (VPT) defined as “treatment which aims at preserving and maintaining the pulp tissue that has been compromised but not destroyed by extensive dental caries, dental trauma, and restorative procedures or for iatrogenic reasons”, offers some beneficial advantages over the conventional root canal treatment such as protective resistance for mastication forces or to prevent the loss of environmental changes sensation ability, which can lead to unnoticeable progression of caries and later fracture. A wide range of materials are suggested in the literature to be used as pulp capping protective dressing materials that varies from ready-made synthetic materials to biological based scaffolds and composites. The aim of the present review is to provide a full understanding of currently used materials to clinicians in order to help in their decision-making process delivering the best available evidence-based treatments to their patients. An extensive search for recent available data regarding direct pulp capping materials and potential suggestions for future use have been made. Newly developed biological based scaffolds showed promising results in dentine regeneration therefore strengthening the tooth structure and overcoming potential drawbacks of use of currently available recommended materials.

Small molecules have demonstrated promising results as successful alternatives to growth factors. In this study, focus was drawn to CHIR99021 and tideglusib as GSK-3 inhibitors known for their anti-inflammatory and regenerative potential. The effect of both tideglusib and CHIR99021 on the proliferation, viability, and stemness of human dental pulp stem cells (hDPSCs) was investigated to assess their possible role in regenerative dentistry. Briefly, hDPSCs were isolated from sound premolars extracted for orthodontic purposes. Cytotoxicity and proliferation assessment were performed via cell counting kit-8 followed by flow cytometric analysis of apoptotic marker ANNEXIN V. The effect of both small molecules on the stemness of hDPSCs was analyzed by qRT-PCR. Both tideglusib and CHIR99021 were proven to be safe on hDPSCs. The tideglusib concentration that resulted in higher viable cells was 100 nM, while the concentration for CHIR99021 was 5 nM. Both small molecules successfully induced cellular proliferation and demonstrated minimal expression of ANNEXIN V, indicative of the absence of cellular apoptosis and further confirming their positive effect on proliferation. Finally, both small molecules enhanced stemness markers expression as evidenced by qRT-PCR, which, again, highlighted the positive effect of both tideglusib and CHIR99021 on safely promoting the proliferation of hDPSCs while maintaining their stemness.