Development of Bioactive Niobium Oxalate-Based Desensitizer: Permeability and Formation of Nanoprecursors

To evaluate the obliteration of dentinal tubules by experimental pastes with different concentrations of niobium oxalate compared to commercial pastes. Experimental pastes were synthesized from mixtures of different concentrations of sodium carboxymethylcellulose and ammonium niobium oxalate. Twenty-five dentin discs, each 1.5 mm thick, were obtained from molars and divided into five experimental groups (n=5): 1) Oxagel (Kota, Brazil); 2) Desensibilize KF 2% (FGM, Brazil); 3) Paste with 5% niobium oxalate (wt%); 4) Paste with 10% niobium oxalate; 5) Paste with 20% niobium oxalate. The pastes were applied, and initial permeability readings were taken immediately, as well as at 7, 14, and 21 days. Measurements were made using the THDO3d device (Odeme, Brazil). Scanning electron microscopy images and analysis of precipitate formation were performed after 21 days (SEM/EDS). The commercial groups showed a greater reduction in Lp (hydraulic conductance) after 7 days, which remained constant until 21 days. The experimental groups, regardless of concentration, showed a high reduction in permeability immediately. SEM images revealed the formation of a thick layer composed of precipitate and the successive application of the material for all experimental groups. Niobium oxalate pastes are capable of significantly reducing dentinal permeability in both the short and long term, regardless of the concentration applied.