I wore my old one out. Think it was 8 years old. I immediately bought another one. These units are awesome for keeping my dental work, teeth and gums CLEAN! Absolutely the best.
I previously owned a Waterpik. After I had a tooth extracted and a lot of other dental work I put salt in the water. It was soothing and refreshed the soreness but it damaged the tubing. I purchased another Waterpik and I am delighted with the way it cleans my teeth. This new model came with a toothbrush attachment and I like to use it before I use the other attachments.
I have one for 4 years. My husband has it in his bathroom and it was a pain to take care of my teeth, so I decided to buy my own and keep it in my bathroom. Use the pik and the gum stimulator 3 x 4 times a week. Also, use the toothbrush with or without water.
We bought this about a month ago, and my husband and I both use it. There are several tips so we can each have our own. We both dental floss, but found this to get food out from teeth that flossing did not remove. A very good product!