Digital Full Dentures-A New Dimension in Prosthetic Treatment?

As in many areas, production steps in dental treatments are increasingly benefiting from digital technologies. Digital full dentures were produced for the first time in 1994 and the process has become quite successful and fast when it comes to today. The base and wax wall prepared on the model obtained from the final measurement, starting with the measurement taken with alginate, which is traditionally applied in the production of full dentures, and shaping the edges of the personal spoon prepared for the model obtained from this measurement, and then taking the second, that is, the final measurement with an impression material that gives better tissue detail. It is a process that continues with the recording of the vertical and horizontal jaw relations with the toothpaste, followed by the gear rehearsal, and then the finishing of the prosthesis in the muffle and its delivery to the patient. It is a treatment that takes about 5-6 sessions even in the shortest and trouble-free condition. Every stage of this process requires sensitive work of both the physician and the technician. The slightest mistake to be made will result in the failure of the prosthesis. This process is also quite expensive in terms of cost.
Digital full dentures will be able to provide an effective solution at this point. Especially in many systems, the 1st Session, which includes the recording of the measurement and vertical-horizontal jaw relations, is reduced to a minimum of 2 and a maximum of 3 sessions, the 2nd Session that can be rehearsed if desired, and the 3rd Session, which will be delivered to the patient, thus saving time.
 
In digital full denture systems, the measurement is usually taken with full toothless spoons, which have different sizes prepared by the companies, usually with plastic prepared spoons for personalized adaptation and abrasion on the edges. However, studies are also continuing to take measurements by scanning the soft tissues directly with intraoral scanners. Additive type silicones, polyethers and zinc oxide eugenol impression materials can be used for impressions. These dimensions are used as heavy body and light body combinations. Since special trays constitute the initial cost, companies have been producing digital prostheses by scanning the measurements taken by using the existing prostheses of the patients as spoons.
Impression trays in the Baltic Denture System produced by Merz Company can be in the form of trays with standard occlusion in Class 1 relationship, which are fixed to each other with a key, and whose occlusion is standardized according to lingualized occlusion. On the spoons prepared by Dentca, after measuring the lower and upper parts separately, the posterior parts are in the form of the back parts that are cut and separated so that they do not collide with each other in the gothic arc drawing. In this system, there is a plastic drawing tip attached to the lower jaw that can move up and down to adjust the vertical dimension, and a flat table on the upper jaw where the gothic arc can be drawn. After determining the centric relationship with the vertical rod and the gothic arc drawing of the vertical dimension, the mutual relations are fixed with the closing silicone and then sent to the laboratory.
 
After the measurement session, which lasts approximately 40-60 minutes, the measurements are first scanned in the laboratory, and then the registration and design processes are carried out with a CAD program with the full prosthesis module open. At this stage, some companies do an occasional control session with pictures and some companies with trial prostheses. These trial prostheses are usually written with dental printers and also incur a cost. Again, although it varies according to the companies, the problems seen in this session are either corrected on the design in line with the physician's request or are corrected by the physician directly at the patient's bedside before the end of the session.
Then, production differences are seen in the companies in the prostheses that are passed to the production, that is, the CAM phase. When CAD/CAM studies are mentioned in this regard, prostheses that are produced by scrapers come to mind first. However, this is a misconception that the production can be obtained by scraping the teeth and the base separately or as a whole from the blocks polymerized under pressure, or it can be produced by 3D printers using light-cured acrylics. The production time takes approximately 1 hour to measure.
 
What are the advantages of digital full dentures?
It saves time due to the number of sessions
Pre-polymerized blocks minimize acrylic shrinkage when scraped, resulting in better tissue fit, better adaptation and a more retaining prosthesis and stable occlusion
Reduces bacterial and candida colonization
The risk of breakage is reduced
No risk of porosity
Provides standardized prosthesis production for scientific studies
When necessary, the lost or broken prosthesis can be produced in the same way by using the data in the archive.
The monomer release is now reduced (The claims of the manufacturers on this subject are not scientifically supported. In a study conducted in 2017, it was reported that there was no difference in monomer release between traditional prostheses and digital prostheses).
 
Journal of the Istanbul Chamber of Dentists