A.S.
I'm a dental hygienist & recommend the Sonicare all the time. They should last an absolute minimum of 2 years. Definitely call the company directly, don't write a letter. I've always had excellent customer service with them whether I'm calling for a patient or for dental office products. On average, Sonicares will go "strong" for about 3-4 years. Afte that, they will often work, but at much less brushing power and should be replaced after that time. Anyone who has an older one & switches to new one will notice the difference.