White lesions after orthodontic treatment: does low fluoride make a difference?

OBJECTIVE

To compare and measure the changes in size of post-orthodontic demineralized white lesion enamel lesions treated with a low fluoride (50 ppm) versus a non-fluoride mouthrinse/toothpaste regime.

STUDY DESIGN

An experimental double-blind prospective randomized clinical controlled trial.

SETTING

A university dental school orthodontic clinic (Sheffield, UK).

PARTICIPANTS

Twenty-six patients identified as having post-orthodontic demineralized white lesions on removal of their fixed appliance. METHOD AND INTERVENTIONS: The participants were randomly and blindly assigned to either a low fluoride mouthrinse/toothpaste treatment regime or an inactive control. Computerized image analysis of calibrated photographic images taken under polarized light were used to measure the lesions.

OUTCOME MEASURES

Lesion size and proportion (DWL%t) and percentage reduction (ADPR) at debond, and at 12 and 26 weeks later.

RESULTS

Five participants dropped out of the study, 12 had the low fluoride regime and 9 did not. As a percentage of the total labial tooth area (DWL%t) the mean size of the lesions at debond was 8.1% (SD 3.7). After 12 weeks the mean size of lesion had reduced to 4.6% (SD 2.6), which was a significant reduction (p=0.03). After 26 weeks the mean size was 3.5% (SD 2.1), which was a very significant reduction (p<0.003). This confirmed statistically that post-orthodontic demineralized white lesions do reduce in size with time reflecting remineralization or other enamel surface changes. Intervention using a test low fluoride mouthrinse/toothpaste combination at 26 weeks showed an average difference percentage reduction (ADPR) of 54.3% (Upper 95% CI=62.08, Lower 95% CI=46.44%) compared with a non-active control combination, which showed an ADPR of 66.1% (Upper 95% CI=77.74, Lower 95% CI=54.51%). This failed to show any differences or therapeutic affect.

CONCLUSIONS

Post-orthodontic demineralized white lesions reduced in size during the 6 months following treatment by approximately half the original size. There was no clinical advantage in using the low fluoride formulation of mouthrinse/toothpaste in this study.