Intraoral pH Associated with Consumption of Mixed Coffee Beverages

Introduction: This pilot study investigated intermittent changes in oral pH (acidity) correlated with consumption of mixed coffee beverages. Changes were hypothesized to be associated with occurrence of demineralization in teeth.

Methods: This observational single subject design study recruited 11 healthy subjects who refrained from eating and oral hygiene behaviors two hours prior to the experiment. Each was asked to consume six, 15mL samples of coffee over a 15 minute period. After chewing paraffin wax, baseline saliva samples were obtained from each subject. At two minute intervals 6 additional samples were collected after subjects swallowed a 15mL dose of coffee drink. This was repeated on three separate days using; plain coffee, coffee/sugar combination and coffee/sugar/cream combination respectively. All saliva samples (n=231) were analyzed using a calibrated pH meter and data were analyzed using repeated measures analysis of variance. Results: After 15 minutes of interval consumption there was a significant difference (p<.001) in oral pH following use of plain coffee, coffee/sugar and coffee/sugar/cream combinations, with a lower pH associated with the combination coffee drinks. However, the lowest pH recorded for any coffee sample, at any time period was 6.6. From baseline, a significant drop in pH was noted with only the coffee/sugar/cream combination Conclusion: Intermittent sipping of three varieties of coffees did not demonstrate a change in pH that could be associated with demineralization of tooth enamel within the 15 minutes of observation.

Future investigations should examine longitudinal measures to more clearly define effects of mixed coffee beverages on tooth demineralization.