Photobiomodulation associated to a 58S bioactive glass for dentin hypersensitivity treatment – an in vitro study on differentiation of human dental pulp cells

To analyze the effects of a 58S experimental bioactive glass associated or not to photobiomodulation (PBM) therapy on the functional differentiation of human dental pulp cells (HDPCs). Dentin discs (1 mm-thick) were mounted on metallic devices, simulating the dental pulp chamber, positioned over HDPC cultures, and the following treatments were applied to the dentin discs, associated or not to PBM (InGaAlP − 660 nm, 5 J/cm², continuous mode, punctual and in contact): BGP - experimental bioactive glass paste; NP - Nupro prophylaxis paste; CXT - Clinpro XT varnish; -control (α-MEM); and +control (Differentiation Medium - DM). After 7, 14 and 21 days, calcium deposition was assessed by the Alizarin Red S staining assay, followed by elution and quantification of calcium, using spectrophotometry. RT-qPCR was used to assess the gene expression for BGLAP, SPP-1, DMP-1, DSPP and IBSP in the negative and positive control, BGP and BGP + PBM groups after 3 days. Data were statistically analyzed (α = 0.05). No significant differences between the experimental groups were found (p = 0.397) at 7 days. BGP group showed greater mineralization potential, differing from α-MEM (p < 0.05), but not from the other groups at 14 days. After 21 days, the BGP, DM, BGP + PBM and CXT groups showed higher mineralization potential, with no significant differences. Regarding gene expression, no significant differences were found for any of the targets tested. The experimental bioactive glass paste and Clinpro XT varnish showed potential for the formation of mineralized nodules after 14 and 21 days, regardless of photobiomodulation.