The purpose of the study was to assess the outcome of school-based oral health education (OHE) and a sugar-free chewing gum program on the oral health status of children in terms of reduced caries increment and gingival bleeding over a period of 2 years. Nine primary schools randomly chosen from one district were divided into three groups: OHE group (Group E), sugar-free chewing gum in addition to OHE group (Group G), and the control group (Group C). All children of grade 1 (aged 6-7 years) were recruited (n = 1342). After 2 years, 1143 children remained in the study group at follow-up. The overall drop-out rate was about 15%. Data on dental caries and gingival bleeding were collected by clinical examination. The results showed that the mean increment of DMFS in Group G was 42% lower than in groups E and C (P < 0.05). The mean increments in F-S were higher in Groups G and E than in Group C (P < 0.01). The gingival bleeding scores were statistically significant among the three groups. Compared to Group C, the mean increment in bleeding scores of Group G was 71% lower (P < 0.01) and in Group E 42% lower (P < 0.05). The school-based OHE programs had some positive effect improving children's oral hygiene; in certain circumstances children may benefit from using polyol-containing chewing gum in terms of reduced dental caries.