If you have dentures, you might be curious as to how an appliance that can withstand the incredible pressure of daily biting and chewing is also fragile enough to break if dropped onto a hard surface. What are dentures made of, and how are they made? We have put together a guide for denture wearers and those who may be curious about dentures, to de-mystify the art and science of creating a new custom oral prosthesis.
First, it’s important to note that there are several different types of dentures, including implant retained dentures, which entered the mainstream scene approximately 30 years ago and consist of replacement teeth permanently anchored into the jaw; partial removable dentures, fixed bridgework, and other types of replacement teeth. For the purposes of our conversation today, we’ll talk about conventional dentures – a word we’ll use to describe the full arch of removable teeth which is held in place by suction to either the lower or the upper jaw, or both. The way that conventional dentures are made holds clues to how other types of replacement teeth are also made.
Materials Used in Making New Dentures
People have been trying to replace lost teeth since ancient times; rudimentary artificial teeth have even been found in ancient Egyptian tombs. Back then, and even up until the mid-twentieth-century, the materials used were what we would consider primitive – animal teeth, bone, ivory, wood and metal, carved or forged to imitate the form and function of our natural teeth. Only one of the known early tooth replacement materials, porcelain, is still in use today.
Fortunately for us, modern technology has made tremendous strides in terms of the materials and the manufacture of artificial teeth. Once truly irreplaceable, our natural teeth now are able to be mimicked very realistically by next generation materials, artfully and scientifically crafted and anchored into the mouth using technology that allows for comfortable wear. Some of the materials in a denturist’s tool kit for crafting new dentures include:
- Wax (to prepare a diagnostic cast)
- Gypsum a.k.a. “Stone” (a heavy duty type of plaster-of-Paris used in making molds of the patient’s mouth)
- Synthetic plastics
- Acrylic resins
- Lightweight metal alloys such as nobelium or chromium
Taking Impressions and Making a Mold
Even before impressions can be made of the gums and mouth, existing teeth whose roots have become irreparably damaged must be extracted, and the gum tissue given time to heal over the course of the next few months as the tooth sockets gradually fill in with bone. Only then, about two to three months after the teeth have been extracted or are lost, is the full denture made.
The first step is for the denturist to make impressions of the oral tissues and the mouth. This is done with a form of putty that is then covered with gypsum to make a hard mold of the mouth. This mold will eventually form the basis of the dentures. It’s important to remember that because the mouth continues to slightly change over time after tooth loss that this original mold may also have to change slightly as the laboratory technician makes the denture over the course of the next month or so.
Why so long to make a denture? Because the denturist must see the patient approximately once per week to measure the dentures every step of the way, making sure they fit perfectly and move according to the patient’s bite. This process doesn’t end once the new permanent dentures are completed; occasional adjustments may be necessary during the months after the denture is made. Even though it takes time to achieve perfection, at Dentures Direct we always provide patients with an immediate temporary denture so they will have something to wear from the moment their teeth are removed. This is only a temporary measure until the permanent appliance has been carefully crafted.
Constructing the Denture
Once the mold has been adjusted so the upper and lower jaws align perfectly, ensuring the denture will eventually move just as your jaw does when you bite, it’s time to mount the teeth. Natural-looking teeth that are suited to a patient’s mouth size and shape, age, sex, skin color, etc. are adhered to the mold with wax, which is then built out and contoured to fully resemble the patient’s gums and mouth tissues.
A separating film is spread on the wax model and, once dry, the mold is injected with liquid acrylic resin which, once the wax is melted off under intense heat, will harden to a durable finish. The sealed mold is then cured in hot water to catalyze the chemical reaction required to permanently harden the resin. This can take about 7.5 to 8 hours. Still curious? Watch this video to see the state of the art equipment and materials a denturist must use to complete the complex and time-consuming process of making a new prosthetic denture.
Fitting the Denture
Although a beautiful, fully functioning denture appliance has now been created, it isn’t necessarily all ready to go. The denture must be put in the model of the patient’s mouth to ensure that it conforms properly to the gums and palate, and that the bite is good. Although the denture should be an exact replica of the model, small discrepancies do occur, and if necessary these can be corrected with minor adjustments, grinding, and polishing. Fine detailing will also be added by hand to ensure that the replacement teeth and resin ‘gum tissue’ looks natural.
At this point the denture is ready for use. Because some time has elapsed, minor changes to the jaw and gums may have occurred that render the new denture slightly uncomfortable. The denturist will work with the patient over the next several weeks to make adjustments until the denture fits perfectly, because even the smallest discrepancy can result in discomfort to a patient when eating or speaking. While the materials used are very lightweight and hypoallergenic, if any reactions or irritations occur, it’s important to let your denturist know right away.
A Smile as Unique as You Are
Every person’s mouth is different, hence no two dentures are alike; even two sets of dentures belonging to the same person can differ because of changes to the mouth that occur over time. A denture must always be custom designed in the painstaking process outlined above, to fit well and look great. Because a denture mold must be broken to extract the denture, a new mold must be made for each new denture.
As you have learned, the fabrication of oral prosthetics is a very precise, intricate process that results in a denture that is absolutely unique to each individual. If you are interested in having a high quality, perfectly fitting denture custom made to replace your current ill-fitting dentures, or if you’d like to learn more about how new denture technologies can restore your smile again, please call Dentures Direct now to book a free, no-obligation consultation at our clinic in Toronto.