Why do some people have to take dental impressions twice when they install dentures?

When installing dentures, it is generally necessary to prepare an impression of the mouth, pour it on the model of the teeth, and then make dentures on the model of the teeth. Therefore, it is very important to take dental casts.

According to the number of impressions taken, it can be divided into primary impression method and secondary impression method. Sampling by one-time impression method is not easy to take all dental impressions, so this method is only suitable for making removable dentures or fixed dentures. The second impression method refers to the extraction of tooth marks by taking the mold twice. Because the impression sampling is complete and the precision is high, this method is especially suitable for making complete dentures and dentures with missing free ends. In clinical practice, the second impression method is used for patients with missing teeth or many missing teeth, so it is difficult to take accurate samples.