An in vitro evaluation of a novel high fluoride daily mouthrinse using a combination of microindentation, 3D profilometry and DSIMS.
OBJECTIVE
Firstly, to evaluate the in vitro anti-erosion efficacy of a new mouthrinse formulation containing 450 ppm fluoride using profilometry and microindentation. Secondly, to compare fluoride uptake by erosive lesions from two mouthrinses containing different fluoride sources using dynamic secondary ion mass spectrometry (DSIMS).


METHODS
Sound human enamel was treated (60s) with mouthrinses containing different fluoride concentrations, then immersed in 1.0% citric acid pH 3.8 for either 300 s or 30 min (Studies 1 & 2 respectively). Surface roughness and erosion depth were determined profilometrically in Study 1, and surface microhardness monitored as a function of time in Study 2. Lesion rehardening was monitored following a 60 s rinse and immersion in artificial saliva for 48 h (Study 3), whilst Study 4 employed DSIMS to quantify fluoride uptake by lesions treated (60s) with rinses containing either sodium fluoride (NaF) or a NaF/Olaflur/stannous chloride combination.


RESULTS
The test rinse (450 ppm fluoride) suppressed surface roughening and bulk tissue loss versus all comparators (p< 0.0001), except in the latter measure for the rinse containing 112 ppm fluoride. The test rinse significantly inhibited enamel surface softening versus the three rinses containing ≤112 ppm fluoride (as NaF) at 30 min (p<0.05), but was not statistically significantly different from the 225 ppm fluoride rinse. The test rinse conferred statistically superior lesion rehardening versus all comparators at both 24 and 48 h (p< 0.0001). DSIMS demonstrated statistically significantly higher fluoride uptake by incipient erosive lesions treated with the test rinse versus the NaF/Olaflur/stannous rinse.


CONCLUSIONS
Anti-erosion efficacy was positively correlated with fluoride concentration. DSIMS showed significantly higher levels of fluoride uptake by incipient erosive lesions treated with the 450 ppm fluoride rinse versus the NaF/Olaflur/stannous rinse.
GlaxoSmithKline Consumer Healthcare, Weybridge, Surrey, UK.
Louise H
LH
Gracia
Gareth D
GD
Rees
Alan
A
Brown
Christabel E
CE
Fowler
D002266:Carboxymethylcellulose Sodium / Q000008:administration & dosage / Q000627:therapeutic use*; D003743:Dental Enamel / Q000737:chemistry / Q000187:drug effects* / Q000648:ultrastructure; D004338:Drug Combinations; D016503:Drug Delivery Systems; D005460:Fluorides, Topical / Q000032:analysis / Q000627:therapeutic use*; D006244:Hardness; D006801:Humans; D021621:Imaging, Three-Dimensional; D013058:Mass Spectrometry / Q000379:methods*; D009067:Mouthwashes / Q000627:therapeutic use*; D010592:Pharmaceutic Aids / Q000008:administration & dosage; D011108:Polymers / Q000627:therapeutic use; D011135:Polysaccharides, Bacterial / Q000008:administration & dosage; D011205:Povidone / Q000008:administration & dosage; D011759:Pyrrolidines / Q000627:therapeutic use*; D013499:Surface Properties; D014077:Tooth Erosion / Q000517:prevention & control*; D014753:Vinyl Compounds / Q000627:therapeutic use*
D004338:Drug Combinations; D005460:Fluorides, Topical; D009067:Mouthwashes; D010592:Pharmaceutic Aids; D011108:Polymers; D011135:Polysaccharides, Bacterial; D011759:Pyrrolidines; C558382:TriHydra; D014753:Vinyl Compounds; C402301:poly(vinylpyrrolidone-co-vinyl-acetate); D011205:Povidone; D002266:Carboxymethylcellulose Sodium; C002563:xanthan gum