Method: The caries status of 47 subjects (6 or 7 years of age) was determined by visual examination. The occlusal surface of the 1st permanent molar was examined by quantitative light fluorescence (QLF) system (Inspektor-Pro, Inspektor Dental Care, The Netherlands), and ΔQ value was used as parameter for evaluating early caries lesion. Lesions were classified as progressing (recovering), if initial ΔQ increased (decreased) by more than 5% between baseline and each examination. When the change was less than 5%, a lesion was evaluated as arrested. These examinations were repeated by 6-month intervals for 2 years. Chewing-gum containing POs-Ca was given 23 subjects (POs-Ca group), and a POs-Ca and fluoride combination chewing-gum was given to 24 subjects (Fluoride group). Every subject chewed two tablets of gum once a day after lunch.
Result: The mean (±SD) dft index POs-Ca group was 5.7 (±3.9) and 4.5 (±3.7) in Fluoride group. And these index values did not change for 2 years. The DFT index was 0 in both groups. And the DFT value increased to 0.2 (±0.1) in POs-Ca group and 0.1 (±0.1) in Fluoride group for 2 years. The QLF examination found 5.4 (±3.6) early caries lesions were detected in POs-Ca group and 4.4 (±4.0) in Fluoride group. After gum usage 16.5% of early caries lesions were recovering in POs-Ca group whereas 46.4% of lesions were recovering in Fluoride group (χ test; p<0.001).
Conclusion: These results suggested that the chewing-gum usage was effective by improvement of the oral health. Especially, chewing-gum containing POs-Ca and fluoride decrease the activity of early caries lesions.