Comparative Impact of Arginine and Stannous Fluoride on Plaque Acidogenicity

Objectives: The suppression of plaque acid can be a significant mechanism for caries prevention. Plaque acidogenicity can be evaluated in the Plaque Glycolysis and Regrowth Method (PGRM) (J Clin Dent 6:59, 1995; FDA 21CFR Part 356 Vol. 68:103, May30 2003). Arginine-containing dentifrice is reported to exhibit a moderate caries prevention benefit (J Clin Dent 24, 2013 Special Issue). High-bioavailable stannous fluoride has likewise demonstrated significant improved anticaries properties (Caries Res 2004; 38:542–550). Anticaries benefits of both technologies can be ascribed in part to their benefits in diminishing plaque acidogenicity. Objective: Evaluate anti-glycolytic and arginine-fermentation activity of an Arginine and a stannous fluoride dentifrice relative to negative control.
Methods: In this randomized double-blind cross-over clinical study (N=28) three commercial dentifrices were tested: CGP(0.454% SnF2 hexametaphosphate, Crest Clinical Gum Protection), CAN (1.1% NaMFP/1.5% Arginine Colgate Neutrazucar); and CR (0.243 % NaF, Crest®Regular – Negative control). Subjects collected baseline plaque samples from the upper dentition and swished 60 seconds with dentifrice (33% in water). Additional plaque was collected from mandibular quadrants 15 and 45 minutes post-treatment. Plaque samples were dispersed in 0.03% TSB and normalized to an OD of 0.20 (600nm). Sucrose was added to initiate glycolysis (37ºC,2 hrs). Arginine fermentation was determined after incubating overnight (0.03%TSB, 0.2M ArgHCl, 50mM tris maleate pH7) using an enzymatic Ammonia assay (Sigma-Aldrich). Cumulative acid inhibition (AUC pH) and arginine fermentation (AUC NH₃) was calculated from baseline, 15 and 45 min values.
Results: AUC pH: CR 21.77a CAN 25.87b CGP 32.58c; AUC NH₃: CAN 8.46a CR 14.20ab CGP 19.51b (a≠b Students-t p <0.05).
Conclusions: High-bioavailable SnF2 dentifrice provided significantly higher plaque-pH following incubation than Arginine in this single-use study. Ammonia production was increased with arginine while decreased with stannous. Longer term studies may provide insight into effects of continuous use of these technologies and proportional impact on caries.