Matrix Production and Cell Proliferation From Novel Pulp Capping Materials

Objectives: Pulp-capping is routinely performed by clinicians to prevent the need for root canal therapy after pulpal or near pulp exposures. Current materials are more effective than traditional calcium hydroxide, but long-term pulp tissue health is still uncertain. Improved pulp-capping materials may afford better pulp capping success. This project compared in-vitro odontoblast-like cell proliferation and extracellular matrix production (ECMP) resulting from two calcium silicate materials (Theracal & Biodentine), and two novel experimental materials (Bioactive Glass - BAG, and a proprietary CaP/CaCO₂-based material, GBF).
Methods: Experimental GBF material was obtained from its maker - its precise composition is proprietary. Experimental bioactive glass (85 mol%SiO₂/11 mol%CaO/4 mol%P₂O₅) was synthesized in our laboratory by the sol-gel route. The other two materials are commercially-available and were purchased from the manufacturers. 1.0 g discs of each material were immersed for 24 hours in 40 ml of Dulbecco's Modified Eagle Medium (DMEM) to allow ion-release to occur. The DMEM was filtered to remove the materials and complete nutrient treatment media was prepared from each of the DMEM samples. MDPC-23 cells were cultured in 24-well plates at 37°C & 5%CO₂ for 24 hours. Treatment media replaced standard media at day 2 of culture and AlamarBlue assays were run every other day to measure cell proliferation. Standard media was used for control samples. An Alkaline Phosphatase (Apase) assay was run on day 8 to evaluate upregulation of ECMP. Cell numbers were compared by ANOVA with post-hoc Tukey (α=0.05).
Results: Theracal and Biodentine-treated cells had significantly lower cell proliferation and Apase levels than the BAG and GBF-treated cells. Cells receiving BAG and GBF-media had slightly higher proliferation than those grown in standard media. GBF-media caused lower Apase production standard-media, while BAG-media caused higher production.
Conclusions: Novel materials BAG and GBF result in greater cell proliferation and Apase production, potentially resulting in higher likelihood of pulp capping success.