RESUMO
The purpose of the present study was to clarify the long-term effects of frequent chewing of unflavored and odorless gum (hereafter, gum base) on oral hygiene and mental health. This single-arm study, which started with a 4-week control and ended with a 4-week intervention period, was conducted in two phases: one in 2017 and one in 2018. The participants comprised 36 dental hygiene students (17 in 2017, 19 in 2018). During the intervention period, all participants were required to chew a piece of gum base 7 times a day for 10 min each time. The unstimulated salivary flow rate and masticatory efficiency were measured and chewing number counted. Two questionnaires ï¼the Profile of Mood States, second edition (POMS2) and the 30-item General Health Questionnaire (GHQ-30)ï¼ were administered to assess mental health. In both phases, the unstimulated salivary flow rate showed a significant increase after the intervention period (p<0.05). In 2017, the GHQ-30 scores and masticatory efficiency showed a tendency toward a negative correlation after the intervention period (r=ï¼0.4647, p=0.06). In 2018, a significant negative correlation was observed between chewing number and the POMS2 scores after the intervention period (r=ï¼0.6296, p<0.01). These findings suggest that frequent chewing of gum base increases unstimulated salivary flow rate. However, no significant change was observed in the mental health.