Antifungal activity of nystatin, miconazole and fluconazole incorporated into four denture liners : in vitro study

Abstract EN

Denture stomatitis is the most common oral disorder found in denture wearers.

It is usually associated with presence of Candida albicans infection.

This study was carried out to evaluate in vitro antifungal activity of incorporated nystatin, miconazole and fluconazole into four denture liners in dry and artificial saliva environments.

The antifungal agents were incorporated as raw material powders into tissue conditioner, cold cured acrylic soft liner, heat cured acrylic resin, and cold cured acrylic resin.

The samples were divided into four groups according to the type of denture liner as follows: Group I : Tissue conditioner-antifungal agents preparations.

Group II : Cold cured acrylic soft liner-antifungal agents preparations.

Group III : Heat-cured acrylic resin-antifungal agents preparations.

Group IV : Cold-cured acrylic resin-antifungal agents preparations.

Each group was subdivided into three subgroups according to the incorporated antifungal agent.

Nystatin was incorporated into denture liners at four different amounts: 120,000 I.U., 240,000 I.U., 480,000 I.U.

and 960,000 I.U.

Miconazole and fluconazole were incorporated at four different amounts: 20mg, 40 mg, 80mg and 160mg.

In dry environment, the denture-liner antifungal sample discs of 0.5mm thickness and 50mm diameter were put in the bottom of the Petri dish and then the culture medium (Sabouraud's agar) was prepared on it in a form of a slant of a depth ranging from 0-8mm.

After solidification, the plate was inoculated with Candida albicans.

Then incubated for 48hrs at 37oC.

After 48hrs, measurements were taken, agar was peeled off, Sabouraud's agar was reapplied and so forth until no inhibition of candida growth was occurred.

In an attempt to imitate the natural environment of the oral cavity, the samples were exposed to artificial saliva for 24hrs at 37oC before each48hrs culturing.

The results showed that, nystatin and miconazole sustained their antifungal activity when incorporated into the four denture liners.

Fluconazole became completely ineffective when incorporated into heat cured acrylic resin, cold cured acrylic resin and cold cured acrylic soft liner.

However, it was the most effective when incorporated into tissue conditioner.

All effective preparations gave inhibition of candida growth that sustained for a period of time that was directly proportional to the amount of incorporated antifungal agent, then it was gradually lost.

Exposure of the samples to artificial saliva gave more rapid loss of antifungal activity of all preparations.

Heat cured acrylic resin and cold cured acrylic resin preparations exhibited more rapid loss of antifungal activity than tissue conditioner and cold cured acrylic soft liner preparations in artificial saliva environment.