Eur. Phys. J. E (2009) 30: 187-195
https://doi.org/10.1140/epje/i2008-10444-x

Regular Article

Dentinal tubules driven wetting of dentin: Cassie-Baxter modelling

¹ Laboratoire PMCN - CNRS UMR 5586, Université Claude Bernard Lyon 1, 43 Bd. du 11 Novembre 1918, 69622, Villeurbanne cedex, France
² Faculté d’Odontologie, Université Claude Bernard Lyon 1, 43 Bd. du 11 Novembre 1918, 69622, Villeurbanne cedex, France

^* e-mail: Stella.Ramos-Canut@lpmcn.univ-lyon1.fr

Received: 24 November 2008
Accepted: 11 February 2009
Published online: 9 April 2009

Abstract

We investigate the wetting properties of dentin surfaces submitted to a phosphoric acid etching followed by an air drying procedure, as in clinical situations of adhesive dentistry. The surface topography of the etched surfaces was characterized by AFM, and the wetting properties of water on these rough and heterogeneous surfaces were studied, by contact angle measurements. We showed that the contact angle increases with the acid exposure time and consequently with both surface roughness and the organic-mineral ratio of the dentin components. From the whole results, obtained on dentin and also on synthesized hydroxyapatites samples, we inferred a water contact angle of ∼ 133^° on the dentinal tubule. These experimental results may be described by the Cassie-Baxter approach, and it is suggested that small air pockets could be formed inside the dentinal tubules.