Authors: J. Earl, D. Wood and S.J. Milne
Affilation: University of Leeds, United Kingdom
Pages: 407 - 410
Keywords: hydroxyapatite, dentinal tubules
Dental hypersensitivity is a problem for large sectors of the population. The problem is caused by the movement of fluid within tiny channels, called tubules, which radiate from the pulp to the surface of the dentine. For the first time we are presenting our results on the use of nanoparticles of hydroxyapatite for the infiltration of dentine tubules as a new method of achieving tubule occlusion for the proposed long term prevention of hypersensitivity. The nanosized hydroxyapatite particles have been made by precipitation and hydrothermal techniques. Reaction conditions have been varied to produce particles with varying size and morphology. Different dispersion fluids and surfactants have been examined in order to produce biocompatible suspensions suitable for in-vitro tubule infiltration. Commercially available silica nanospheres were studied as a ‘model’ system, prior to commencing the hydroxyapatite infiltration trials, in order to demonstrate proof-of-principle. Examination by scanning electron microscopy revealed tubule occlusion using both nano-silica suspensions and hydroxyapatite which was in the form of nano-rods with maximum length 200nm and width 50 nm. Dual beam focussed ion beam lithography, and the construction of a 3D model from individual sections, is demonstrated as a valuable new technique for determining the depth of tubule infiltration. The effectiveness of different particle sizes and infiltration methods are discussed.