For Prime members only, Amazon offers the Oral-B Vitality Floss Action Rechargeable Electric Toothbrush for $19.96. Clip the $5 off coupon on the product page to cut it to $14.96. With free shipping, that's the lowest total price we could find by $8 and tied with our mention from two weeks ago for the best price we've seen. It features MicroPulse bristles, a 2-minute timer, rechargeable battery, and two replacement brush heads.
Update: It's now only available exclusively for Prime members.