Effects of buffering properties and undissociated acid concentration on dissolution of dental enamel in relation to pH and acid type

Shellis, R. P.; Barbour, M. E.; Jesani, A.; Lussi, A. (2013). Effects of buffering properties and undissociated acid concentration on dissolution of dental enamel in relation to pH and acid type. Caries research, 47(6), pp. 601-611. Karger 10.1159/000351641

CariesRes.pdf - Published Version
Available under License Creative Commons: Attribution-Noncommercial (CC-BY-NC).

Download (261kB) | Preview

To quantify the relationships between buffering properties and acid erosion and hence improve models of erosive potential of acidic drinks, a pH-stat was used to measure the rate of enamel dissolution in solutions of citric, malic and lactic acids, with pH 2.4-3.6 and with acid concentrations adjusted to give buffer capacities (β) of 2-40 (mmol·l(-1))·pH(-1) for each pH. The corresponding undissociated acid concentrations, [HA], and titratable acidity to pH 5.5 (TA5.5) were calculated. In relation to β, the dissolution rate and the strength of response to β varied with acid type (lactic > malic ≥ citric) and decreased as pH increased. The patterns of variation of the dissolution rate with TA5.5 were qualitatively similar to those for β, except that increasing pH above 2.8 had less effect on dissolution in citric and malic acids and none on dissolution in lactic acid. Variations of the dissolution rate with [HA] showed no systematic dependence on acid type but some dependence on pH. The results suggest that [HA], rather than buffering per se, is a major rate-controlling factor, probably owing to the importance of undissociated acid as a readily diffusible source of H(+) ions in maintaining near-surface dissolution within the softened layer of enamel. TA5.5 was more closely correlated with [HA] than was β, and seems to be the preferred practical measure of buffering. The relationship between [HA] and TA5.5 differs between mono- and polybasic acids, so a separate analysis of products according to predominant acid type could improve multivariate models of erosive potential.

Item Type:

Journal Article (Original Article)


04 Faculty of Medicine > School of Dental Medicine > Department of Preventive, Restorative and Pediatric Dentistry

UniBE Contributor:

Shellis, Peter and Lussi, Adrian


600 Technology > 610 Medicine & health








Eveline Carmen Schuler

Date Deposited:

05 Mar 2014 15:16

Last Modified:

25 Jan 2017 12:15

Publisher DOI:


PubMed ID:






Actions (login required)

Edit item Edit item
Provide Feedback