Dental erosion is one of the most common causes of tooth surface loss The early stage of enamel erosion, where demineralisation causes a reduction in mineral density but no bulk tissue loss occurs, is reversible as the lost mineral ions can be replaced by those naturally present in saliva. demineralisation process is unchecked or particularly aggressive, the enamel scaffold is lost completely and bulk tissue loss, which is irreversible, results.
objectives commercial mouthrinses containing 0−450ppm ﬂuoride on erosion progression in enamel using a simulated 5-day in vitro cycling model with concurrent monitoring of surface microhardness (SMH) and bulk tissue loss.
‘preparation of enamel specimens’ Bovine teeth were obtained in accordance with current local legislation from slaughtered cattle of single stock aged ~30 months. Cylindrical cores 7mm in diameter were drilled out of bovine incisors using a Bosch Universal Professional Plus Diamond Core drill.
‘preparation of enamel specimens’ The resulting specimens, containing enamel of ~3mm depth, were mounted in acrylic resin, cured overnight, and both sides polished ﬂat using wetted 1200 silicon carbide grit paper using an Ecomet® 250 GrinderPolisher The exposed enamel was further polished with wetted 2500 silicon carbide (SiC) grit paper, followed by diamond polishing usingTexmet® 1500 cloth (Buehler,D¨usseldor
‘preparation of enamel specimens’ Specimens were subsequently rinsed thoroughly with tap water from a non-ﬂuoridated supply, and stored in a humidiﬁed atmosphere at 4ºC. Immediately prior to use,an erosion window was created on the specimen using Cello tape
‘prevention of enamel surface softening’ Topical application of ﬂuoride should be a preferred strategy owing to its ease of use and its proven efﬁcacy in prevention of enamel demineralization.
The ﬁve mouthrinses purchasedfor this study were as follows: Rinse A: Listerine®Original (Johnson & Johnson, Maidenhead, Berkshire,UK); Rinse B: Scope® Original Mint (Procter & Gamble,Cincinnati, OH, USA); Rinse C: Colgate® Plax Cool Mint(Colgate Palmolive, Guildford, Surrey, UK); Rinse D:Aquafresh® ExtraFreshDailyMildMint(GlaxoSmithKlineConsumerHealthcare,Brentford,Middlesex,UK);RinseE:Sensodyne® Pronamel® Daily Mouthwash(GlaxoSmithKlineConsumer Healthcare,Brentford,Middlesex,UK).
Each cycle comprised immersion of eachgroup of specimens in 1.0% citric acidmonohydrate pH3.2 (200mL, 5min, 27ºC,50rpm) followed by artiﬁcial saliva pH7.0(200mL, 120min, 35ºC, 20rpm).
This effect was most marked in the specimen group treated with Rinse E where the mean lesion depth was directionally lowest at every measurement point throughout the study Treatment with Rinse E, containing 450ppm ﬂuoride, elicited numerically lower mean erosion depths compared to all other rinses at all time points, with differences in in vitro efﬁcacy statistically signiﬁcant from day 3 onward. Bulk tissue loss of enamel in the present simulated 5-day in vitro cycling erosion model is inversely proportional to the ﬂuoride concentration of the rinse treatment