Injection Molding: How are Dentures Made

Injection Molding: How Are Dentures Made

By Carter Kho

What’s the process of making dentures?

  1. Impression forming
  2. Injection molding
  3. Mold Heating
  4. Post mold preparations


Dentures are basically false teeth that can either be fixed or removed. They are a replacement for when your teeth become irreparable. It’s very important to replace a missing tooth because when there’s a space in between your teeth, all of your other teeth will gradually tilt toward the gap.

Today, dentures are primarily made through methods from injection molding China. It’s a much more hygienic and practical process when compared to the old ways of manufacturing them. Before dentures were made of animal teeth, pieces of bone, and sometimes a small amount of ivory.

Advancements in technology have led to improved techniques in creating and affixing dentures. Plastic manufacturers have created synthetic plastic resin that make dentures more durable and natural-looking along with some lightweight metal alloys.

With that, take a look at the efforts that are put into creating dentures!

Impression Forming

Impression Forming

Dentures are custom-made every time a need for them arises because they have to fit perfectly and look as natural as possible. Creating a denture begins with creating a preliminary impression of the patient’s mouth. Most of the time, this is done using wax. The impression created will be used to prepare a diagnostic cast.

During the process of impression formation, the dentist constantly applies pressure on your soft tissues. This recreates biting force, and it also extends the borders of the bold to adjacent areas. This allows the dentures to adapt better to the gums of the patient.

After creating a preliminary cast from the impression collected, the final cast is made from gypsum. Before going any further, the final mold needs to be inspected and approved before it can be used to manufacture the dentures.

Injection Molding

Injection molding

Once the mold is approved, it can then be cast. It must first be prepared with a release agent to ensure that when it’s time to remove the hardened acrylic, it will be easier to do. After it’s prepared, the acrylic resin will be injected in.

In some cases, a sheet of separating film between the acrylic and the model is placed to make it easier to remove.

Afterward, the prosthodontist or dental technician mixes the proper resin compounds in liquid form and then left to dry. Proper drying results in the hardening of the resin in order to achieve a durable finish.

The mixture of acrylic resin is packed into the mold while a set of vertical vise packs it tightly. By this time, the model can be inspected to make sure that it’s filled in properly. If there are signs that it still needs an additional resin, then it can still be added.

Aside from injection molding, another method for this is to simply pour particular types of acrylic into the mold. Though still plausible, this method is much more prone to air bubbles than hand packing. Injection molding is very efficient and it is useful for a lot of applications, denture manufacturing included. It is one of the most vital parts for the production of dentures for everyone around the world.

Mold Heating

Mold Heating

Once the prosthodontist is satisfied with how the mold has been packed, heating commences. Heating the mold starts a chemical reaction that causes the resin to harden even further. This process can take up to eight hours.

After the wait, the mold is left to cool. When it’s safe to work with, the mold is broken apart, effectively removing the denture. If it still needs a bit of fine-tuning such as brushing or chipping off bits of the mold that remains on it, it is essential to perform it immediately to avoid problems in the future.

To make sure that the denture is suitable, it’s placed on a model of the patient’s mouth. In doing so, the dental technician would be able to ensure that it fits and there aren’t any problems with how it bites.


Post Mold Preparations

When the dentures are finished, the next procedures depend on whether it’s a removable type or a fixed one. For removable dentures, the process is virtually finished, and it only needs a few minor cleanings and then it’s ready for use!

Fixed dentures would require a professional prosthodontist to drill holes into the jaw of a patient as well as to attach an anchor there. These holes need to be left to heal for three to six months. Afterward, another surgical procedure needs to be done to implant the dentures into the jaw!


Key Takeaway

Dentures are an engineering marvel. With the help of plastic manufacturers, it’s become very easy to replace lost or broken teeth in a rather sensible way. The process itself is precise and smooth and needs a lot more appreciation since it’s usually done behind closed doors.