ABSTRACT
PURPOSE: Stannous fluoride has a long history of use in the improvement of oral health, and was the fluoride source first proven to provide anti-caries benefits when delivered from a dentrifrice formulation. This paper provides an account of the early use of stannous fluoride, primarily for an anti-caries benefit, and the subsequent attempts to formulate stannous fluoride into stable formulations where additional benefits of the stannous cation can be realized.
Subject(s)
Dentifrices/therapeutic use , Dentin Sensitivity/drug therapy , Tin Fluorides/therapeutic use , Calcium Pyrophosphate/therapeutic use , Dental Caries/prevention & control , Dentifrices/chemical synthesis , Dentifrices/chemistry , Drug Combinations , Fluorides/therapeutic use , Humans , Phosphates/therapeutic use , Polyphosphates/therapeutic use , Tin Fluorides/chemical synthesis , Tin Fluorides/chemistry , Tooth Discoloration/prevention & controlABSTRACT
Pseudomonas aeruginosa PAO1 possesses two distinct lipopolysaccharide (LPS) O-polysaccharide species, A- and B-band LPS, the relative expression of which appears to be under environmental control. In an attempt to identify the influence these LPS types have on surface characteristics and adhesion, we examined the surface hydrophobicity and surface charge of P. aeruginosa PAO1 (O5 serotype) and its isogenic LPS derivatives which possessed A+B-, A-B+ and A-B- LPS. The surface characteristics of the strains affected their ability to adhere to hydrophilic (glass) and hydrophobic (polystyrene) surfaces. Cells possessing only A-band LPS demonstrated the highest surface hydrophobicity, followed by the strain lacking both A- and B-band LPS. The presence of B-band LPS resulted in a more hydrophilic surface. Strains lacking B-band LPS (A+B- and A-B-) had more electronegative surfaces than those possessing B-band LPS (A+B+ and A-B+), with cells lacking both A- and B-band LPS showing the highest surface electronegativity. These data suggest that the main surface-charge-determining groups reside in the core region of the LPS molecule. Cells with the lowest surface hydrophobicity and lowest surface charge (A+B+, A-B+) adhered to glass the most efficiently, implying a role for electrostatic interaction, whereas adhesion to polystyrene mirrored the relative hydrophobicities of the strains (A+B- > A-B- > A+B+ > A-B+). It is postulated that phenotypic variation in the relative expression of A- and B-band LPS may be a mechanism by which P. aeruginosa can alter its overall surface characteristics in such a way as to influence adhesion and favour survival.
