Clinical and laboratory evaluation of powered electric toothbrushes: laboratory determination of relative abrasion of three powered toothbrushes.

Previously established data on average forces applied to various brushing instruments during in vivo toothbrushing were incorporated into a laboratory abrasion model. The apparatus included a specially constructed and standardized brushing machine and utilized an acrylic resin substrate. Three powered brushing instruments (Rota-dent, Interplak and Braun Oral-B Plaque Remover) and a manual toothbrush (Oral-B P40), were compared in this model. The system demonstrated excellent precision and could distinguish between brushing instruments with as little as 10% difference in abrasivity. It was found that brushing abrasivity increased in the order of Rota-dent < Braun < Interplak.