Thesis (Ph.D.)--Chulalongkorn University, 2013

Objective: The purpose of this study was to evaluate the potential of a novel varnish containing potassium chloride and fluoridated hydroxyapatite in terms of physical properties for DH management and cytotoxicity in vitro. Method: Fluoridated hydroxyapatite was synthesized by precipitation method. The chemical analysis of the powder was performed by X-ray photoelectron spectroscopy and Fourier transmission infrared spectroscopy. The morphology was characterized by scanning electron microscopy. The novel varnish containing potassium chloride and fluoridated hydroxyapatite was formulated. Potassium ions released from the varnish were measured by inductively coupled plasma-optical emission spectrometry. Dentin permeability measurement was conducted and permeability reduction percent from the varnish was calculated and compared to fluoride and control varnishes. Dentinal tubule occlusion was observed by scanning electron microscopy. Direct contact test and MTT assay were performed for cytotoxic evaluation. Results: The results showed that the novel varnish could release potassium ions over 6 h. Specimens applied by the novel varnish demonstrated statistically higher dentin permeability reduction to fluoride varnish and placebo. Scanning electron microscopy observation exhibited dentinal tubule occlusion in the novel varnish. Direct contact test and MTT assay showed its biocompatibility to gingival and pulpal fibroblasts with respect to fluoride varnish. Conclusion: This study suggested the potential of the novel varnish as a promising biomaterial for dentin hypersensitivity management with no cytotoxicity to human gingival and pulpal fibroblasts.