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Influence of fluoride–detergent combinations on the visco‐elasticity of adsorbed salivary protein films
Author(s) -
Veeregowda Deepak H.,
van der Mei Henny C.,
Busscher Henk J.,
Sharma Prashant K.
Publication year - 2011
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1111/j.1600-0722.2010.00798.x
Subject(s) - toothpaste , chemistry , saliva , adsorption , fluoride , sodium fluoride , x ray photoelectron spectroscopy , nuclear chemistry , chemical engineering , inorganic chemistry , biochemistry , organic chemistry , engineering
Veeregowda DH, van der Mei HC, Busscher HJ, Sharma PK. Influence of fluoride–detergent combinations on the visco‐elasticity of adsorbed salivary protein films. Eur J Oral Sci 2011; 119: 21–26. © 2011 Eur J Oral Sci The visco‐elasticity of salivary‐protein films is related to mouthfeel, lubrication, biofilm formation, and protection against erosion and is influenced by the adsorption of toothpaste components. The thickness and the visco‐elasticity of hydrated films (determined using a quartz crystal microbalance) of 2‐h‐old in vitro‐adsorbed salivary‐protein films were 43.5 nm and 9.4 MHz, respectively, whereas the dehydrated thickness, measured using X‐ray photoelectron spectroscopy, was 2.4 nm. Treatment with toothpaste slurries decreased the thickness of the film, depending on the fluoride–detergent combination involved. Secondary exposure to saliva resulted in a regained thickness of the film to a level similar to its original thickness; however, no association was found between the thickness of hydrated and dehydrated films, indicating differences in film structure. Treatment with stannous fluoride/sodium lauryl sulphate (SnF 2 /SLS)‐containing toothpaste slurries yielded a strong, immediate two‐fold increase in characteristic film frequency ( f c ) with respect to untreated films, indicating cross‐linking in adsorbed salivary‐protein films by Sn 2+ that was absent when SLS was replaced with sodium hexametaphosphate (NaHMP). Secondary exposure to saliva of films treated with SnF 2 caused a strong, six‐fold increase in f c compared with primary salivary‐protein films, regardless of whether SLS or NaHMP was the detergent. This suggests that ionized stannous is not directly available for cross‐linking in combination with highly negatively charged NaHMP, but becomes slowly available after initial treatment to cause cross‐linking during secondary exposure to saliva.