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<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 signif-icant treatment differences between the three traditional floss products.