3D dental impressions for the fully edentulous patient.
Other than the hard palate and alveolar ridges, there really are no other stationary landmarks. All of the soft tissue and muscle attachments move in function. Some patients have moveable mucosa that extends well onto the crest of the mandibular ridge. Can a digital scanner accurately record the full depth of the vestibule and the range of motion of the soft tissue while in function in order to fabricate a denture that fits well?
Consider what we have to do when taking a physical dental impression for dentures. Dentists typically adapt or customize the impression tray to approximate the patient’s anatomy and use an impression material that will capture the full depth of the vestibule. We also have the patient move their tongue and cheeks in the early stages of the impression setting to capture the range of motion. This is how we, as clinicians, obtain a good-fitting set of dentures — with well-adapted, accurate impressions that fully capture all of the fine details of the patient’s anatomy and an impression that has suction when removed from the mouth.
Currently, there are case studies in the dental literature that have fabricated impression-free dentures utilizing scanners that are available now. Many of these studies involve making dentures to near completion. Because the fit or the occlusion was not ideal, a dental laboratory remount was performed to improve the occlusion and/or the denture was border molded in order to extend the flanges and a denture reline impression was taken to reprocess the dental appliance for the purpose of improving the fit before the final denture delivery.
From a dental practice standpoint, these things amount to a lot of extra steps. Realistically speaking, would your patient come for the additional appointments required and would the necessary extra steps to obtain great fitting dentures “impression-free” be cost-effective for you? The procedure is really not “impression-free” if you must take denture reline impressions to make them fit correctly.