Impact of different fluoride concentrations and pH of dentifrices on tooth erosion/abrasion in vitro

Abstract

Background: This in vitro study analysed the effect of different fluoride concentrations in acidic or neutral liquid dentifrices in protecting enamel and dentine from erosive and abrasive wear. Methods: Bovine enamel and dentine specimens (n = 132) were randomly allocated to 11 groups (each n = 12): experimental liquid dentifrices with 550 ppm F, 1100 ppm F, 5000 ppm F or 0 ppm F/placebo (each at pH 4.5 and pH 7.0); and commercial dentifrices with 550 ppm F (Colgate Baby, pH 7.0), 1100 ppm F (Crest, pH 7.0) and 5000 ppm F (Duraphat, pH 7.0). The specimens were subjected to erosion for 90 seconds, 4 times/day, over 7 days. Immediately after the first and last erosion, the specimens were brushed for 15 seconds using one of the dentifrices. Tooth wear was measured profilometrically (lm) and analysed by ANOVA (p < 0.05). Results: All fluoridated liquid dentifrices significantly reduced enamel wear compared to the placebo and commercial dentifrices. Only liquid dentifrices with 1100 and 5000 ppm F significantly reduced dentine wear compared to placebo dentifrice. The pH had no effect, but the consistency had a significant impact on the effect of dentifrices. Conclusions: Liquid dentifrices with high F concentration appear to be a good option to prevent tooth wear.

Three-dimensional profilometric assessment of early enamel erosion simulating gastric regurgitation

“…33 The present model is a proof of concept for profilometric detection of early erosion and is an advance in profilometric assessment for several reasons: (1) A higher sensitivity of the profilometer in this study enabled earlier changes in surface roughness (i.e. after 30 s of erosion) to be detected compared with the longer durations described previously, [21][22][23][34][35][36] (2) Enamel specimens were polished flat to a level of 0.25 mm compared with approximately less than 9.0 mm in recent atomic force microscopic studies, or to 1.0 mm in surface nanohardness studies, 23,37,38 (3) The longitudinal design incorporated both quantitative and qualitative assessments (without the need for surface coating or negative impressions for qualitative assessment), (4) 3D surface roughness (Sa) was measured over areas of 43 mm  43 mm compared with linear measurements in previous studies, 34,39 and (5) The Sa values were collected longitudinally from the same areas of enamel. Our detection sensitivity for profilometric changes in the Sa values is comparable to those of between one and two minutes in recent reports, [39][40][41][42] and, collectively, these findings add to the need to diagnose the initial stages of early erosion as soon as possible in the clinic.…”

Protective effects of a zinc-hydroxyapatite toothpaste on enamel erosion: SEM study

“…The incorporation of protective agents in toothpastes has become increasingly common; also because dental sensitivity, a problem often related to acid erosion, is a common complaint among patients. Currently, conventional fluoridebased toothpastes do not seem to be able to effectively protect teeth against erosion (5). Recently, new toothpastes formulations have been introduced to contrast enamel and dentin erosion.…”

Atomic force microscopy study of enamal remineralization

“…Fluoride dentifrices have some protective effect on enamel eroded to brushing abrasion when immersed in vitro in a cola drink (8). Currently, conventional fluoridecontaining toothpastes do not appear to be able to protect efficiently against erosion (9). Colgate Sensitive Pro Relief (Colgate-Palmolive, New York, NY, USA) is based on arginine 8% (Pro-Argin ™ ).…”