Product Development Background


Curvex and its derivatives were developed to offer innovative toothbrushes with bristle arrays that would not only geometrically fit the most difficult-to-clean areas of the mouth, but would also utilize the softest filaments in the accepted range of “soft” toothbrushes, while maintaining plaque removal efficacy. Within this category, 0.007 inches diameter bristle filaments are the most commonly used, but they can be as large as 0.008 inches, (also the start of the “medium range”) or as small as 0.006 inches (typically labeled Extra Soft.)

From the outset of the development effort, three main considerations were recognized:(1) the softer the bristle, the greater the risk that bristle deformation would occur from brushing in the customary to-and-fro motion; (2) a softer bristle must achieve an adequate level of plaque removal; and (3) if a softer bristle could be successfully integrated into the brushhead design, there could be benefits to the gingival health of the user, as well as creating a more comfortable brushing experience.


Blinded Clinical Evaluation

In 2005, a single-blind crossover study was conducted to compare plaque removal using Curvex against the Oral-B 40 Indicator, widely recognized as the best-selling toothbrush in the world.  Led by


Journal Article

Dr. Harada was asked by the editors of the Journal of the American College of Dentists to write the developmental narrative of the Curvex toothbrush for inclusion in the Spring 2006 edition.  The article describes how Dr. Harada conceived and



Please contact Dr. Stephe Harada at [email protected] or write Dr. Harada at:

Stephen Harada, DDS
Ergonomic Dental Technologies, Inc. 
500 Sansome Street, Suite 604
San Francisco, CA 94111-3211