Objective: Videofluoroscopy was used to compare drinking from a cup with drinking through straws of two varying bore diameters in different positions in the mouth.
Design: Clinical study at a single centre.
Setting: UK dental school.
Subjects and methods: Twenty patients showing clinical signs of erosion which had necessitated advice and/or treatment.
Interventions: Subjects drank from a cup and through a narrow straw, which was then repositioned more posteriorly. A wide bore straw was used in two equivalent positions. Swallowing was viewed laterally and anteroposteriorly to assess involvement of incisors and molars respectively.
Main outcome measures: Video recordings examined for presence or absence of fluid contact with teeth following each swallow. If contact occurred, the time was measured.
Results: Fourteen patients avoided fluid contact with both incisors and molars when using a straw. Compared with the cup, significant differences were found with the narrow straw (P = 0.03, 95% confidence interval of 22.6% to 31.6%), the narrow straw repositioned (P = 0.008, 95% confidence interval of 12.3% to 47.1%) and the wide straw repositioned (P = 0.03, 95% confidence interval of 3.1% to 37.5%). Contact time of fluid with anterior teeth was also significantly reduced.
Conclusions: Drinking through a straw positioned toward the back of the mouth may reduce the erosive potential of soft drinks.