Masticatory Performance Alters Stress Relief Effect of Gum Chewing.

Purpose: We evaluated the effects of gum chewing on the response to psychological stress induced by a calculation task and investigated the relationship between this response and masticatory performance.Methods: Nineteen healthy adult volunteers without dental problems undertook the Uchida-Kraepelin (UK) test (30 min of reiterating additions of one-digit numbers). Before and immediately after the test, saliva samples were collected from the sublingual area of the participants. Three min after the UK test, the participants were made to chew flavorless gum for 3 min, and the final saliva samples were collected 10 min after the UK test. The experiment was performed without gum chewing on a different day. Masticatory performance was evaluated using color-changing chewing gum.Results: Salivary CgA levels at immediately and 10 min after the UK test were compared with and without gum chewing condition. Two-way repeated measures analysis of variance revealed significant interaction between gum chewing condition and changes in CgA levels during post 10 min UK test period. A significant correlation was found between changes in CgA levels and masticatory performance in all participants.Conclusion: Our results indicate that gum chewing may relieve stress responses; however, high masticatory performance is required to achieve this effect. (C) 2015 Japan Prosthodontic Society. Published by Elsevier Ireland. All rights reserved.