Role of dentifrices on abrasion of enamel exposed to an acidic drink.
OBJECTIVE
To evaluate in vitro the abrasive potential of different dentifrices on enamel previously exposed to an acidic soft drink.


METHODS
150 bovine enamel slabs measuring 6 x 3 x 2 mm were grounded flat and polished. Surface roughness was measured to obtain Ra (microm) baseline values using a profilometer. The slabs' outer surface was covered with a tape except for a 3 x 4 mm window. According to a randomized complete block design, specimens were exposed to an acidic drink or distilled water (control) for 5 minutes, and then to artificial saliva for 1 minute. Next, the experimental units were submitted to 5,000 brushing strokes using one of four dentifrices - regular (RE), baking soda (BS), tartar control (TC) or whitening (WT) - or distilled water as control (CO) (n=15). At the end of five repetitions of this erosive/abrasive cycle, the tape was removed and final readings of surface roughness were carried out. Roughness gain consisted of the subtraction of the baseline values from the post-treatment measurements. Also, the enamel wear due to erosive/abrasive challenges was profilometrically determined.


RESULTS
ANOVA did not show significant interaction between enamel condition (eroded and sound) and dentifrice (P> 0.05) for both roughness gain and wear. No significant effect was found for enamel condition and dentifrice in the wear analysis. The exposure of enamel to the acidic drink provided higher roughness gain than did distilled water. Tukey's test evidenced that TC yielded significantly greater increase in surface roughness than did both CO and WT, whereas BS and RE induced an intermediate roughness gain.
Turssi
Cecilia Pedroso
CP
Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Brazil.
Messias
Danielle Cristine Furtado
DC
de Menezes
Márcio
M
Hara
Anderson Takeo
AT
Serra
Mônica Campos
MC
D000704:Analysis of Variance; D000818:Animals; D002253:Carbonated Beverages / Q000009:adverse effects*; D002417:Cattle; D045424:Complex Mixtures / Q000627:therapeutic use; D003802:Dentifrices / Q000627:therapeutic use*; D006801:Humans; D011122:Polyphosphates / Q000627:therapeutic use; D011897:Random Allocation; D012824:Silicic Acid; D012822:Silicon Dioxide / Q000627:therapeutic use; D017693:Sodium Bicarbonate / Q000627:therapeutic use; D012969:Sodium Fluoride / Q000627:therapeutic use; D018709:Statistics, Nonparametric; D013499:Surface Properties / Q000187:drug effects; D014072:Tooth Abrasion / Q000209:etiology*; D014077:Tooth Erosion / Q000139:chemically induced / Q000188:drug therapy* / Q000209:etiology; D014099:Toothbrushing / Q000009:adverse effects*; D014100:Toothpastes
D045424:Complex Mixtures; D003802:Dentifrices; D011122:Polyphosphates; D014100:Toothpastes; C546060:hydrated silica gel-based toothpaste; D012824:Silicic Acid; D012822:Silicon Dioxide; D017693:Sodium Bicarbonate; D012969:Sodium Fluoride