Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
Have used this "Oral Care" for our cats for a number of years now. It is useful for keeping their teeth in good shape. However, our vet still advised giving them other things, such as chicken wings, in addition to the dry food.