20/11/2019 0 Comments
How Dentures Are Made?
Typically, dentures take anywhere from 5 to 8 appointments to make. This means you will need to be in our office five to eight times within a week apart each time. These amounts and times vary greatly from patient to patient.
Below is the step-by-step treatment of a patient who has no teeth remaining in their mouth. As I said before, treatment varies greatly on a patient-to-patient basis and even more so when there are natural teeth or implants involved. Each numbered step is a clinical step in which you are required to be in office, each lettered step is a lab step where we work with the previous clinical steps outcomes to provide the correct materials for the next step.
- Preliminary Impressions
- Pour impressions and craft custom trays
- Border-moulded Final Impressions
- Pour final impressions and craft wax rims
- Vertical Registration, Face-bow Transfer, and Tooth Selection
- Craft pin tracers for horizontal jaw registration
- Horizontal Registration
- Set teeth in wax
- Process try-in
- Denture Delivery
- Post-insertion Care
- Clinical Remount and Occlusal refinement
1. We will take alginate impressions of your mouth in order to make models of your gums. These impressions are taken using general-sized trays that fit most patients’ mouths.
a. We pour a liquid-type stone, similar to concrete, into the impressions. This liquid stone then hardens. Then those stone models are used to make custom-fitting impression trays. These trays are made out of plastic and will fit specifically in your mouth.
2. We will use the custom trays to take accurate impressions of your gums. We use a light silicone material, which precisely mimics the surface detail of your gums. By getting detailed impressions, we can ensure that the denture base is fully extended. The denture bases need to be fully extended in order to cover as much space as possible. It is important that the new dentures are well adapted to your gums so that they fit as closely as possible. Dentures act like snow shoes in this sense, spreading the weight of the chewing forces evenly across the gums.
b. At this point we use a denser liquid stone to pour our models. These models must be of high quality as this will be the base for the finished denture to be made on. Once the stone models are ready, we build a wax version of the dentures to capture a preliminary bite.
3. At this appointment we will use the wax rims that will be shaped like your new denture to find the right position and angle to set the teeth. We also will need to find the correct jaw distance, which we call speaking space. The average speaking space in any given person is about 1-4 mm. At this appointment, the speaking space will be assessed to determine what is the healthiest for you. We will also be looking at your teeth to put in your new denture. At this time, we will be able to choose teeth that fill an appropriate amount of space in your mouth as well as decide what colour of tooth to use.
c. During this lab step, we will be crafting wax rims again. But instead of making them of just wax, we place a metal plate on the top and a ballpoint on the bottom. Using this plate and ballpoint, we will be able to find the correct position for your jaw to be in, in horizontal movements.
4. During this appointment, we will be using a device called a pin-tracer to confirm the most natural place for your jaw to close. Making movements such as forward and back, and side to side. The ballpoint of the pin tracer will draw a specific design that we will use to determine the best place for your jaw to bite. This is a difficult appointment, and we need to be quite diligent with our procedure and make sure we get you to close in the right position.
d. We will take this final bite of the pin-tracers and set your stone models on to a jaw simulator called an articulator. Once the models of your gums are in the same position on the jaw simulator as they're in your mouth, we will set teeth at the desired place and look that has been determined with the wax rims. We will use the colour of tooth selected at this appointment as well. If you have a picture of what your teeth used to look like, we can use that picture to mimic our set up like your old natural teeth.
5. Here, we will be trying in a wax version of the new denture. We will confirm the look of your new teeth as well as their arrangement and any technical aspects of the denture. During this step, we will confirm the location and overlapping of the teeth to make sure they are in the right place. At this stage, we can make any changes we need to because the teeth are only set in wax. We will not proceed to finish your dentures into acrylic until we have confirmed the look, and that we think your dentures are technically correct. We may need to have more than one try-in appointment if we change the size, colour, or location of the teeth.
e. Once you have confirmed the look of the teeth and we have confirmed that the teeth are functioning correctly, we can proceed to turn the wax into a highly dense plastic called acrylic. We take the final wax try-in and pour liquid stone around it. Once the stone sets up and hardens, we set the whole thing into boiling water to melt the wax away. After making sure that the stone is clean and free of wax, we pump liquid acrylic into the space where the wax used to be. The acrylic and stone are then placed into a tank of water under pressure which allows the liquid plastic to cure into hard plastic.
6. At the delivery appointment, you will receive your new dentures. We will do some minor adjustments to the denture bases and have a final look at the ‘bite’. We will talk to you about what to expect during the adaptation period with your new dentures as well as advise you on the best way to clean your dentures and take care of your gums. The new denture teeth are going to be sharper than your old denture teeth. This will at first feel strange but with time, will become more normal.
7. We will book an appointment to see you within seven days of receiving your new dentures because it is highly likely you will need some adjustments to relieve soreness. It is normal to get sore spots with new dentures, so we allow a three-month period of free adjustments as you get used to wearing your new teeth.
8. After you wear the dentures for an extended period of time, the denture settles into the gums slightly, so we like to make sure that the settling has not affected the way the teeth function. Usually, this appointment takes place at least two weeks after you receive the dentures.
That is a summary of how dentures are made! It is important to realize that the bone under the dentures is always changing! The denture will never fit better than the first few months after insert. In order to keep the fit nice and tight and the bone healthy, dentures must be relined and re-fitted every 1-2 years, and the whole set of dentures must be replaced every five years.
- Joshua Schaefer