Hard template construction of nano-beta-tricalcium phosphate and nano-hydroxyapatite root canal sealing materials

Li Qian; Qumanguli·Abudukelimu; Shao Ziyu; Hu Yang

doi:10.12307/2026.657

Abstract：BACKGROUND:At present,root canal sealants have the shortcomings of poor biocompatibility,mechanical properties,and degradation,and nano-β-tricalcium phosphate and nano-hydroxyapatite materials have good biocompatibility,degradability,and sealability,and have important research value in the field of root canal sealants. OBJECTIVE:To construct new root canal sealing material with microscopic morphology and three-dimensional structure similar to the hard tissue structure of the tooth by controlling the nucleation,growth,and reconstruction of nano-β-tricalcium phosphate and nano-hydroxyapatite crystals by the dentin sheet hard template method METHODS:Totally 30 discarded third molars extracted due to impacted wisdom teeth were collected and dentin slices were prepared.Different masses of nano-β-tricalcium phosphate(or nano-hydroxyapatite)were dissolved in distilled water,and the solution was poured into a culture dish containing a dentin slice and placed in a 37℃ constant temperature incubator for 12 hours to obtain 10％,20％,and 30％ nano-β-tricalcium phosphate/dentin slices and 10％,20％,and 30％ nano-hydroxyapatite/dentin slices,with pure nano-β-tricalcium phosphate and nano-hydroxyapatite as controls.The eight groups of samples were characterized and analyzed by scanning electron microscopy,Raman spectroscopy,X-ray diffractometer,and X-ray photoelectron spectroscopy. RESULTS AND CONCLUSION:(1)Scanning electron microscopy:Under the regulation of dentin slices,the microstructure and morphology of nano-β-tricalcium phosphate and nano-hydroxyapatite changed.The morphology of nano-β-tricalcium phosphate particles changed from irregular polygons to short rods and spheres,arranged in three-dimensional clusters,and the morphology of nano-hydroxyapatite particles changed from rods and needles to short rods and other forms.Nano-β-tricalcium phosphate and nano-hydroxyapatite particles were orderly arranged between the dentin collagen fiber network,and with the increase of nano-β-tricalcium phosphate or nano-hydroxyapatite concentration,the adhesion and agglomeration phenomenon became more and more obvious,and the arrangement became more and more dense.(2)Raman spectroscopy:Under the regulation of dentin slices,the functional groups of nano-β-tricalcium phosphate and nano-hydroxyapatite did not change,but with the increase of nano-β-tricalcium phosphate or nano-hydroxyapatite concentration,the intensity of the functional group characteristic peak increased.(3)X-ray diffraction:Under the regulation of dentin slices,the crystallinity of nano-β-tricalcium phosphate and nano-hydroxyapatite increased,the crystal structure became more complete,and the grains became smaller.Among them,30％ nano-β-tricalcium phosphate/dentin slices and 30％ nano-hydroxyapatite/dentin slices had the best crystallinity.(4)X-ray photoelectron spectroscopy:Under the regulation of dentin slices,the elemental composition of nano-β-tricalcium phosphate and nano-hydroxyapatite remained unchanged,but some chemical state changes and characteristic peak intensity enhancement characteristics appeared.(5)The results show that the characterization performance of nano-β-tricalcium phosphate or nano-hydroxyapatite composites constructed with dentin slices as hard templates is stable,and dentin slices have a certain regulatory function on nano-β-tricalcium phosphate and nano-hydroxyapatite.Among them,30％ nano-β-tricalcium phosphate/dentin slices and 30％ nano-hydroxyapatite/dentin slices have better characterization performance.