A long interspace brush, designed to remove plaque from a larger space between teeth and along the gumline. Wisdom Interspace is an excellent choice for when fine precision is required during cleaning some of the more difficult to reach areas between the teeth and along the gum margin. This brush is also effective at cleaning around crowns, bridgework and orthodontic appliances.
This depends largely on your usage. As a rule of thumb, replace your interspace brush weekly, or when it is visibly damaged, there are wire concerns, you notice it is not cleaning well, or if you have been ill recently.
Yes, this brush can be used by those with crowns, bridges, braces etc.