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Number of participants allocated to treatment per period.
| U Group | P Group | H Group | N Group | |
|---|---|---|---|---|
| Period 1 | 5 | 6 | 6 | 5 |
| Period 2 | 6 | 5 | 5 | 6 |
| Period 3 | 6 | 6 | 5 | 5 |
| Period 4 | 5 | 5 | 6 | 6 |
U: U-shaped automatic electric toothbrush. P: Conventional powered toothbrush. H: Habitual tooth brushing procedure. N: No brushing (negative control).
