Evaluation of calcium hydroxide incorporated with niobium pentoxide as a direct pulp capping agent – A preliminary ex vivo tooth culture model analysis

Abstract

Aims: To assess the effect of addition of niobium pentoxide (NP) to calcium hydroxide (CH) when used as a pulp capping agent. The aim was to evaluate the material characteristics and hydration potential of CH incorporated with NP at 15 days in vitro followed by the evaluation of dentin bridge formation in an ex vivo tooth culture model.Materials and Method: Two groups, CH (Dycal) and NPCH (5wt% NP added to Dycal prior to mixing) were mixed and the set cement was evaluated under scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD). NPCH was also used for direct pulp capping in two freshly extracted human mandibular third molars for dentin bridge evaluation. The teeth were incubated in Dulbecco modified eagle's medium for 15 days, following which the teeth were sectioned and analyzed for hard tissue formation under SEM.Results: SEM analysis of the modified material revealed interlacing network with stronger attachment of the agglomerated CH particles and reactionary by-products formed due to the interaction of CH and NP. EDS analysis showed presence of calcium and oxygen; with Group 2 showing additional presence of niobium and phosphate. XRD showed higher intensity peaks with NPCH than CH. The tooth culture model showed distinct hard tissue formation.Conclusion: Within the limitations of this preliminary study, it can be concluded that the incorporation of NP into CH is a viable alternative to CH for direct pulp capping procedures.