A videofluoroscopic comparison of straw and cup drinking: the potential influence on dental erosion

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.