Plaque-removal efficacy of four types of dental floss

BACKGROUND: Effective plaque removal is essential for gingival health, and dental floss is used to augment plaque removal achieved with a toothbrush. METHODS: This randomized, controlled, examiner-masked, five-period crossover study examined plaque removal in 25 subjects following single use with an American Dental Association reference manual toothbrush alone and in combination with four floss products: three traditional (unwaxed, woven, and shred-resistant) and one powered flosser. Plaque was scored before and after brushing for 1 minute. The Rustogi modified Navy plaque index was used to focus scores on tooth areas contacted during the proper use of dental floss. RESULTS: Mean plaque reductions (baseline minus postbrushing) in floss contact areas were as follows: 0.181 with the toothbrush alone; 0.228, 0.217, and 0.210 for the toothbrush in combination with the three traditional flosses, unwaxed, woven, and shred-resistant, respectively; and 0.252 for the toothbrush plus powered flosser. No statistically significant differences were found between the three traditional floss treatments. All four floss treatments showed greater (P <0.05) mean plaque removal than the toothbrush alone. Mean plaque removal with the powered flosser combination was greater than for the woven combination and shred-resistant combination (both P < or =0.006) and fell just short of significance compared to the unwaxed combination (P = 0.051). CONCLUSIONS: All four floss products in combination with a manual toothbrush removed plaque significantly better than the toothbrush alone. Among floss types, there was evidence of superiority for the powered flosser, but there were no significant treatment differences between the three traditional floss products.