Almost two-thirds of denture-wearers in the US frequently experience what's known as denture-related stomatitis – fungal infections of the mouth. In order to try and bring that number down, scientists have recently created 3D-printed dentures that release fungus-killing medicine.
Led by Dr. Praveen Arany, a team from the University at Buffalo printed the prototype dentures out of Poly methyl methacrylate (PMMA), which is currently the standard denture-making material. For the outer layer of the dentures, that PMMA was mixed with biodegradable microspheres filled with the antifungal medication Amphotericin B. These spheres both protected the medicine from the heat of the printing process, and subsequently allowed it to gradually leak out as they degraded.
In lab tests, the dentures were found to be highly effective at eradicating Candida albicans fungus over a sustained period. When they were strength-tested alongside conventionally-manufactured dentures, they turned out to have 35 percent less flexural strength, although the machine that was bending them never did succeed in actually breaking them. It's possible that their strength could be improved by adding glass fibers and carbon nanotubes to the material.
The scientists also experimented with applying one, five and 10 layers of the microsphere-containing PMMA, although it turned out that more wasn't necessarily better. "We were trying to test if multiple layers could effectively enable increased dose and longer sustained drug delivery, but this turned out to be incorrect," Arany tells us. "We observed that only the one-surface 3D-printed layer degrades effectively (five and 10 appear to be irreversibly heat fused, 'trapping' the drug)."
With this in mind, he adds that a possible alternative to 3D-printing a set of the dentures from scratch would be to just take a patient's existing dentures, scan them, abrade away their outer layer, and then replace it with a layer of the Amphotericin B-enhanced PMMA. That said, for patients getting their first set of dentures, there would be an advantage to getting them 3D-printed – the build process would only take a matter of hours, as opposed to days or even weeks for traditional dentures. They would also be less expensive.
Arany now hopes that the technology could be applied not only to dentures, but also to fungus-killing splints, stents, casts and prostheses.
A paper on the research was recently published in the journal Materials Today Communications.
Source: University at Buffalo
