The Gum Toothbrush 491 Has A Unique, Raised Center With Dome-Trim® Bristles That Has Been Clinically Proven To Clean Under The Gum Line Where Periodontal Disease Begins. The Patented Quad-Grip® Handle Helps To Position The Brush At The Correct 45 Degree Angle For Optimal Cleaning. The Ultra-Cushion On The Handle Is Extremely Large For Comfort And Stability When Brushing