Tooth lost a piece, mainly due to calculus off, dental trauma, filling material off, etc., as follows: 1, calculus off: due to eating hard things, resulting in attached to the tooth surface of the calculus off, this situation indicates that the calculus has been more, should be as soon as possible in the hospital, for full mouth cleaning, remove the oral tartar and other adverse stimuli. 2, dental trauma, etc.: due to dental trauma, dental caries caused by the hard tissue of the tooth, after eating or by external force, the tooth fracture, split, then should be in the hospital for examination, If there are no pulp symptoms, such as toothache and tooth sensitivity, the defective part can be filled with special dental filling material directly. If you have pulp symptoms, you should first cover the pulp of the tooth or remove the pulp, root canal treatment, and then carry out the filling of the defective part. 3, the filling material falls off: the tooth has been repaired, there has been filling material, the filling material will fall off after a long time, this situation should also be seen in the hospital to re-fill the defective part.