Drug-filled, 3D printed dentures may fight fungal infections

Washington: Scientists, including one of Indian origin, have 3D printed novel dentures that periodically release medication to prevent fungal infection which causes inflammation, redness and swelling in the mouth of the users.

Unlike current treatment options, such as antiseptic mouthwashes, baking soda and microwave disinfection, the new development can also help prevent infection while the dentures are in use. "The major impact of this innovative 3D printing system is its potential impact on saving cost and time," said Praveen Arany, an assistant professor at University at Buffalo in the US.

To better treat these infections, called denture-related stomatitis, researchers have turned to 3D printers, using the machines to build dentures filled with microscopic capsules that periodically release Amphotericin B, an antifungal medication.

The technology allows clinicians to rapidly create customised dentures chair-side, a vast improvement over conventional manufacturing that can vary from a few days to weeks, said Arany.

The research could be applied to various other clinical therapies, including splints, stents, casts and prosthesis. "The antifungal application could prove invaluable among those highly susceptible to infection, such as the elderly, hospitalized or disabled patients," he said.

The dental biomaterials market - worth more than USD 66 billion in 2015 - is expected to grow 14 percent by 2020. A large part of the industry is focused on dental polymers, particularly the fabrication of dentures.

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. To test the strength of the teeth, 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 3D printed dentures was 35 per cent less than that of the conventional pair, the printed teeth never fractured.

To examine the release of medication in the printed dentures, the team 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 investigation 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 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 researchers found 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 aims to reinforce the mechanical strength of 3D printed dentures with glass fibres and carbon nanotubes, and focus on denture relining - the readjustment of dentures to maintain proper fit.