[This review was collected as part of a promotion.] i liked oral b io ultimate clean refillls. it is very comfortable. my teeth is very clean and fresh . effectivness is really high . you must tryyyy

[This review was collected as part of a promotion.] The durability of these hair brushes were good. The scent and the packaging was very nice. It was a value for my money. I love the effectiveness of these toothbrushes.

[This review was collected as part of a promotion.] These brushes cleaned my teeth so well and made my teeth shine and feel so fresh. They hold up to 3x a day with out losing formation. My husband and I really enjoy using these brushes day to day.

[This review was collected as part of a promotion.] I love how clean and smooth and polished my teeth feel with this toothbrush and its toothbrush heads. Soft yet effective bristles. Easy to put on and off.

[This review was collected as part of a promotion.] These toothbrush refill heads work great! Easy to put on and use and really do a great job of comfortably keeping my teeth clean! They are a good value for what you get and are really durable!

[This review was collected as part of a promotion.] I didn’t know how much better an electric brush was till I went to the dentist. She said my build up was so much better and she wanted to know what I changed. It was my Oral B io !

[This review was collected as part of a promotion.] I like using oral b electric tooth brush. I like the ultimate clean oral b brush head. they seems good and clean my teeth very well. I think it is good value for money.

[This review was collected as part of a promotion.] I like that there are 4 pieces in the package. They change color when you need to change the nozzle. Comfortable to clean. OralB iO Ultimate Clean Refills - Compatible with Oral-B iO Electric

[This review was collected as part of a promotion.] It’s very important brushing your teeth. This is the best toothbrush you can found and the price is really reasonable. Although it has 4 options and I always use the sensitive one .

Really does a great job of cleaning teeth, while being gentle on gums. Question: What is the function of that narrow little slot which is just under the bristles?