Effect of 4 days consumption of chewing gum containing sorbitol or a mixture of sorbitol and xylitol on dental plaque and saliva

By aid of a full crossover double-blind design, the effect of a 4-day period with: (1) ten pieces per day of a sorbitol-containing chewing gum, (2) ten pieces per day of a chewing gum containing a mixture of sorbitol and xylitol (sorbitol/xylitol), and (3) no chewing gum, in combination with a controlled diet and no oral hygiene, was studied on dental plaque and saliva in 24 dental students. Sorbitol-containing chewing gum did not enhance the amount (wet weight) compared to no chewing gum. The sorbitol/xylitol period resulted in significantly less plaque in comparison with the two other periods (p < 0.001). No clearcut differences were found between the three treatments regarding protein content and peroxidase activity in whole-saliva centrifugates or total carbohydrate, reducing sugar, protein content and 'sucrase' activity in soluble plaque extracts. Directly after these 4-day periods, the effect of 3-hour consumption of ten pieces of a sucrose-containing chewing gum was studied. Protein content and peroxidase activity in whole-saliva samples were about the same after this 3-hour period, while plaque wet weight, protein, total carbohydrate and reducing sugar content and 'sucrase' activity in soluble plaque extracts increased significantly (p < 0.001). The changes in the plaque material after the 3-hour period were about the same and independent of the former treatment with sorbitol-and sorbitol/xylitol-containing chewing gum or no chewing gum.