There are both full and partial dentures. Full or complete dentures replace all the teeth in an arch. A removable partial denture usually anchors with clasps or gaskets to some remaining teeth and replaces the missing ones with the denture teeth.
For a conventional denture, ideally the failing teeth are removed and the gum tissue is given time to completely heal, which may be up to several months. This typically permits a more accurate impression of the ridge(s) to be taken and fewer adjustments required when inserted. Multiple steps are taken to set up the teeth for the denture and the look and feel of the teeth can usually be tried in before the final denture is processed. However, in our experience, most patients do not want to be without their teeth during this healing period, so another option is often used, called an immediate denture.
In a case with an immediate denture, the impressions are taken with the teeth still in place in the patient's mouth. Models are poured up from the impressions and sent to the lab. Calculations are made with the lab and the teeth are removed from the models (not the mouth) and the dentures are processed before the teeth are removed. This kind of denture cannot be tried into the mouth until the teeth are extracted.
The processed denture is then returned to our office and the day the teeth are extracted is the day the denture is placed in the mouth. Usually some adjustments to the denture are required, perhaps with more follow-up visits to adjust the fit. However, the advantage is that the patient does not have to be without teeth, and usually the extraction sites heal quickly and the dentures are ready to be used nearly immediately.