There are several possible causes for a small piece of the inside of a tooth to break off. 1. It may be due to a splitting of the tooth. When chewing harder foods the teeth produce cracks, which can easily lead to a small piece of the tooth breaking off. This kind of teeth can be covered by braces to ensure the normal chewing force. 2. A small piece of the inner side of the tooth may be broken off because of the caries. When there is no timely filling of tooth decay, it is easy to lead to the crumbling of tooth enamel, and it is easy to appear a small piece of broken phenomenon, it is generally recommended to carry out filling in time, if the filling is not perfect, you can also do braces to repair. 3, a small piece of broken inside of the tooth, there may be dental calculus, and long-term failure to clean it is easy to misunderstand that a small piece of broken teeth, in fact, it is The calculus has fallen off by itself.