These studies compared the effects of
Crest Dual Action Whitening dentifrice with
sodium hexametaphosphate and control commercial
dentifrices on the surface chemistry of conditioning film-coated dental enamel in vitro and in vivo. Conditioning film chemistry was studied by measurements of film thickness, ability to wet the surface/surface energy, conditioning film chemical composition and zeta potential. Laboratory and in vivo studies demonstrated that brushing and chemical-only treatment of pellicle-coated enamel surfaces produced marked changes in surface chemistry. Brushing of surfaces with all commercial
dentifrices significantly reduced pellicle film quantity. Effects on non-brushed areas, of significance in the clinical situation, were different for different
dentifrices. For
dentifrice chemical treatments,
calcium phosphate surface active builders, such as
pyrophosphate and
hexametaphosphate, produced stronger effects than standard (non-
tartar control)
dentifrices,
peroxide baking soda dentifrices and
dentifrices formulated with carboxylate
polymers, viz.
Colgate Total with copolymer. Crest Dual Action Whitening
hexametaphosphate dentifrice removed more pellicle conditioning film, produced a lower zeta potential, produced the largest changes in film composition and had the greatest impact on surface free energies of the tested
dentifrices.
Crest Dual Action Whitening dentifrice also produced lasting changes in the reacquisition of pellicle conditioning film, as established by in vitro cycling immersion studies.
Crest Dual Action Whitening dentifrice produced stronger and more lasting effects on surface film chemistry than low molecular weight
pyrophosphate (
Crest Tartar Control) or other polymeric-based
dentifrice systems (
Colgate Total). These surface chemistries may contribute to the unique clinical actions of
hexametaphosphate established in recently reported, randomized clinical studies of
tartar control,
stain prevention and
stain removal effects.