Cellular differentiation, bioactive and mechanicalproperties of experimental light-curing pulpprotection materials

Abstract

Objective. Materials for pulp protection should have therapeutic properties in order to stim-ulate remineralization and pulp reparative processes. The aim of this study was to evaluatethe mechanical properties, biocompatibility, cell differentiation and bioactivity of experi-mental light-curable resin-based materials containing bioactive micro-fillers.Methods. Four calcium-phosphosilicate micro-fillers were prepared and incorporated into aresin blend: 1) Bioglass 45S5 (BAG); 2) zinc-doped bioglass (BAG-Zn); 3) TCP-modified cal-cium silicate ( -CS); 4) zinc-doped -CS ( -CS-Zn). These experimental resins were testedfor flexural strength (FS) and fracture toughness (FT) after 24 h and 30-day storage in sim-ulated body fluid (SBF). Cytotoxicity was evaluated using MTT assay, while bioactivity wasevaluated using mineralization and gene expression assays (Runx-2 & ALP).Results. The lowest FS and FT at 24 h was attained with -CS resin, while all the other testedmaterials exhibited a decrease in FS after prolonged storage in SBF. -CS-Zn maintained astable FT after 30-day SBF aging. Incorporation of bioactive micro-fillers had no negativeeffect on the biocompatibility of the experimental materials tested in this study. The inclu-sion of zinc-doped fillers significantly increased the cellular remineralization potential andexpression of the osteogenic genes Runx2 and ALP (p < 0.05).