Assessing the Antifungal Activity of a Soft Denture Liner Loaded with Titanium Oxide Nanoparticles (TiO2 NPs)

Abstract

Aim: Soft denture lining materials are susceptible to be colonized by different microorganisms, especially by Candida albicans (C. albicans), causing denture-induced stomatitis. This study was designed to evaluate the effectiveness of incorporating titanium dioxide nanoparticles (TiO₂ NPs) into a soft denture liner towards reducing microbial activity.

Method: A total of 40 PEMA-TiO₂ nanocomposites samples were fabricated by adding 0.0 wt.% (control), 1.0 wt.%, 1.5 wt.%, and 2 wt.% TiO₂ NPs to a heat cured soft denture lining material (polyethyl methacrylate, PEMA). The prepared samples were divided into four groups (n = 10) according to the content of TiO₂ NPs. The uniformity of TiO₂ NPS distribution within the denture liner matrix was assessed using a Scanning Electron Microscope (SEM). The viable count of C. albicans was evaluated to test the antifungal resistance of the developed composite.

Results: The SEM images showed fairly homogeneous dispersion, with patches of TiO₂ NPs agglomeration within the PEMA matrix and an increasing concentration of NPs with higher NP content. The particle map and EDX analysis confirmed the evidence of the TiO₂ NPs. The mean viable count results for the control (0.0 wt.%) and 1.0 wt.%, 1.5 wt.%, and 2 wt.% TiO₂ groups were 139.80, 12.00, 6.20, and 1.00, respectively, with a significant difference from the control group (p < 0.05). The antifungal activity also increased with the increase in the concentration of TiO₂ NPs.

Conclusions: The addition of TiO₂ NPs into a heat-cured soft denture liner provided antifungal activity as evidenced by the reduced colonization of C. albicans. The antimicrobial activity of the liner material increased with the increased concentration of TiO₂ NPS.

Keywords: Candida albicans; antifungal agent; denture liners; nanoparticles; polyethyl methacrylate; titanium oxide.

Figure 1

(A) Plastic patterns and (B) plastic patterns imbedded in silicone mold and stone, and (C) the molds after removing the patterns.

Figure 2

Soft liner specimens after curing (A) within the molds and (B) outside the molds.

Figure 3

(A) Photographs of colonies of C. albicans on SDA and (B) optical microscopy image of candida, which appears as Gram-positive small oval or budding yeast cells.

Figure 4

Formation of the C. albicans germ tube.

Figure 5

(A) SEM image, (B) Ti and O particle map, and (C) EDX analysis of the TiO₂ NPs.

Figure 6

SEM images of (A) PEMA and PEMA-TiO₂ nanocomposite: (B) 1.0 wt.% (C) 1.5%, and (D) 2.0 wt.%.

Figure 7

Box plot of the C. albicans viable count for different PEMA-TiO₂ nanoparticle groups and the control group (pure PEMA). A horizontal line connecting two groups indicated a statistically significant difference.

Figure 8

SDA plates showing CFU/mL of C. albicans for each group of study: (A) control with a large number of fungal colonies compared with the nanocomposites with different TiO₂ NPs concentrations showing a decreased number of colonies: (B) 1.0 wt.% (C) 1.5%, and (D) 2.0 wt.%.