Objectives: to produce a nanoscaled Potassium-containing Fluoridated Hydroxyapatite via sol-gel process and to evaluate the effect on the dentin through SEM and CLSM.
Methods: Hydrofluoric acid and potassium nitrate was selected as fluorine-containing and Potassium-containing reagents to add into mixed Ca (NO3)2-P2O5 ethanol solutions to form dipping sols. The properties of the novel material were investigated by EDX.Paired premolars extracted for the reason of orthodontics were selected to test group and control group. The cervical dentin was cut and polished perpendicular to the axis of the dentinal tubules in order to obtain a flat surface with opened tubules. The novel composite was applied to the test group teeth and no treatment was applied to the control group teeth. The surface morphology of the dentin was observed by Scanning Electron Microscopy. And the interface of specimens was observed by Confocal Laser Scanning Microscope after rhodamin B was dipped into the material.
Results: All of the resulting samples showed apatite structure in their XRD patterns. The lattice parameters a and the crystallite size was calculated to demonstrate the crystalline structure of Potassium-containing Fluoridated Hydroxyapatite. SEM indicated that the tubules were covered by a 10 µm layer of Potassium-containing Fluoridated Hydroxyapatite particles and in the 10µm inside tubule diameter, hydroxyapatite particles were observed. CLSM images also showed that the red fluorescence had deposit on the dentin tubules when employing naturally shaped fractions of premolars as specimen.
Conclusions: The Potassium-containing Fluoridated Hydroxyapatite can be produced successfully through sol-gel process. Fluorine and potassium were incorporated into hydroxyapatite. The material particles came into the tubule and closed the orifice which implied that the novel material is a promising candidate as a new active ingredient to alleviate the Dentin Hypersensitivity.