There is no strict clinical requirement as to how long you can eat after a scaling. Scaling is simply a process of removing plaque and calculus from the periodontium of our mouth through ultrasonic scaling. It does not cause much damage to the human body, so there are no special requirements or time requirements for eating. However, most of the patients will have some medication placed in the gingival sulcus, such as iodine glycerin, after the scaling. These medications are recommended to be kept for a period of time because the iodine glycerin can act as a disinfectant and astringent. If you eat too early, there is a possibility that these drugs will be absorbed directly with the digestive tract going down. So from this aspect, you can consider eating half an hour after scaling to let the medication act for some time. Of course, nowadays, some people apply some anesthetic in the process of scaling because it is more painful, and the action time of the anesthetic is usually around 2 hours, so if the scaling and anesthetic is used, you can consider eating after 2h. This is mainly because the teeth and gums are less sensitive after the application of anesthetic, there is a possibility of cheek biting or tongue biting when eating, of course the chances of this are not particularly high, but since it can be avoided, it is better to try to avoid it.