title: Cetylpyridinium chloride adsorption on the wettability and elemental surface composition of human enamel.
abstract: To determine the influence of cetylpyridinium chloride (CPC) adsorption on the wettability and elemental surface composition of human enamel, with and without adsorbed salivary constituents, surface-free energies and elemental compositions were determined. The surface-free energies were estimated from contact angle measurements; whereas the elemental compositions were determined by X-ray photoelectron spectroscopy. Surface-free energies of ground and polished enamel (88 +/- 8 mJ.m-2 and saliva-coated enamel (103 +/- 4) became similar (109-112) upon adsorption of CPC. Also, the N/C concentration ratios of the ground and polished enamel surface (0.06) and saliva-coated enamel (0.21) become equal upon CPC adsorption. The N/C concentration ratio after CPC adsorption (N/C = 0.04) corresponds with the value expected on basis of the molecular structure of CPC. The strongest evidence for adsorption of CPC to both ground and polished enamel and saliva-coated enamel is presented by the double nitrogen N1s peak. This double nitrogen1s peak is not observed for ground and polished enamel nor for enamel with a salivary coating on top of adsorbed CPC, which indicates that adsorbed CPC can be completely screened by salivary proteins. This study demonstrates that CPC has a definite capacity to adsorb both on ground and polished enamel as well as on pellicle-coated enamel.
authors.forename: H C
authors.initials: HC
authors.lastname: van der Mei
authors.forename: J F
authors.initials: JF
authors.lastname: Perdok
authors.forename: M
authors.initials: M
authors.lastname: Genet
authors.forename: P G
authors.initials: PG
authors.lastname: Rouxhet
authors.forename: H J
authors.initials: HJ
authors.lastname: Busscher
mesh_terms: D000327:Adsorption; D002594:Cetylpyridinium; D003743:Dental Enamel / Q000033:anatomy & histology*; D044622:Dental Pellicle; D006801:Humans; D011726:Pyridinium Compounds; D013499:Surface Properties
chemical_list: D011726:Pyridinium Compounds; D002594:Cetylpyridinium