Purpose: Purpose of this work is to give a review about the consequences of a swallowed or aspirated foreign object during dental treatment. Materials and methods: An aspirated foreign object can be life threatening. When the foreign object slides through the glottis it can get stuck in the area of the trachea, which can result in respiratory insufficiency leading to respiratory arrest in case of a total block of the respiratory tract. In 2/3 of the cases the foreign object reaches over the steeper and wider right main bronchus into the area of the right lung. The Dentist and the assistant should in case of an aspirated foreign object be firm with the technique to keep the respiratory ducts free as well as with the technique of artificial respiration. If the patient is conscious and has a stable circulation he should promptly be leaded with an elevated upper part of the body and under permanent oxygen supply to a clinic with the possibility of bronchoscopic extraction of the foreign object after its radiographic identification. Results: To avoid such incidents rubber dam should be used during endodontical treatment. Root canal pins should be secured with dental floss during their try-in. A gauze could avoid the swallowing or aspiration of prostheses during the try-in. Should a unilateral removable denture be delivered it should under all circumstances be supplied with a precision attachment. Conclusions: During dental treatment with small instruments or objects there is always the danger of they being swallowed or aspirated. Safety precautions should be used where ever it is possible, otherwise one may be accused of being negligent. Palabras clave: Verschlucken, Aspiration, Beatmung, Riegel