Nearly two-thirds of the people who wear dentures in the United States suffer frequent fungal infections known as denture-related stomatitis that cause inflammation, redness, and swelling in the mouth, according to the University at Buffalo (UB) School of Dental Medicine.
To better treat these infections, the school is using 3-D printers to build dentures filled with microscopic capsules that periodically release Amphotericin B, an antifungal medication. Unlike current treatments such as antiseptic mouthwashes, baking soda, and microwave disinfection, these dentures can reduce fungal growth and help prevent infection while they are in use.
“The major impact of this innovative 3-D printing system is its potential impact on saving cost and time,” said Praveen Arany, DDS, PhD, senior author of the study and an assistant professor in the Department of Oral Biology at the school. Arany also has an appointment at the UB Department of Biomedical Engineering.
The technology enables clinicians to rapidly create customized dentures chair-side, which is a vast improvement over conventional manufacturing that can vary from a few days to weeks, Arany said. Applications, Arany added, could include other clinical therapies such as splints, stents, casts, and prostheses.
“The antifungal application could prove invaluable among those highly susceptible to infection, such as the elderly, hospitalized, or disabled patients,” Arany said.
Worth more than $66 billion in 2015, the dental biomaterials market is expected to grow 14% by 2020, the university reports. A large part of this industry is focused on dental polymers, particularly the fabrication of dentures.
The researchers printed their dentures with acrylamide, the current go-to material for denture fabrication. The study sought to determine if these dentures maintained the strength of conventional dentures and if the material could effectively release antifungal medication.
The researchers used a flexural strength testing machine to bend the dentures and discover their breaking points. A conventional lab-fabricated denture was used as a control. Although the flexural strength of the 3-D printed dentures was 35% less than that of the conventional pair, the printed teeth never fractured.
To examine the release of medication in the printed dentures, the researchers filled the antifungal agent into biodegradable, permeable microspheres. The microspheres protect the drug during the heat printing process and allow the release of medication as they gradually degrade.
The study involved the development of an innovative form of acrylamide designed to carry antifungal payloads and a novel syringe pump system to combine the dental polymer and microspheres during the printing process, the researchers said.
The dentures were tested with one, five, and 10 layers of material to learn if additional layers would allow the dentures to hold more medication. The sets with five and 10 layers were impermeable and were not effective at dispensing the medication. Release was not hindered in the more porous single layer, and fungal growth was successfully reduced.
Future research will aim to reinforce the mechanical strength of 3-D printed dentures with glass fibers and carbon nanotubes and focus on denture relining, the readjustment of dentures to maintain proper fit.