Evaluation of the effect of EDTA on the antifungal properties, flexural strength, and colour stability of heat polymerised PMMA resin for implant overdentures

Evaluation of the effect of EDTA on the antifungal properties, flexural strength, and colour stability of heat polymerised PMMA resin for implant overdentures

Purpose: To evaluate the effect of ethylenediaminetetraacetic acid (EDTA) on the antifungal properties, flexural strength, and color stability of heat polymerized polymethyl methacrylate (PMMA) denture base resin. Materials and Methods: Eighty PMMA heat cure denture base resin test samples of the following sizes were fabricated: 10×1 mm (disc), 64×10×3.3 mm (strip), and 50×0.5±0.05 mm (disc) with or without EDTA. The PMMA heat cure denture base resin samples formed one group (GROUP I, n=40) and PMMA heat cure denture base resin samples incorporated with 8% EDTA were the second group (GROUP II, n=40). These were further subdivided according to the testing parameters as follows: Qualitative analysis of antifungal properties (GROUP I: 10 and GROUP II: 10), quantitative analysis of antifungal properties (GROUP I: 10, GROUP II: 10), flexural strength, and colour stability, 10 samples each for both groups and properties. The antifungal properties of GROUP I and GROUP II were evaluated qualitatively and quantitatively by measuring the zone of inhibition using the disc diffusion method and colony forming units (CFU), respectively. The flexural strength and color stability were evaluated using the three-point bend test and a spectrophotometer. The color difference (ΔE) was calculated. Results: The mean zone of inhibition for GROUP I and GROUP II samples was 0 mm and 9.2 mm, respectively. The mean CFU of GROUP I and GROUP II was 119.50×106 and 45×, respectively. The mean flexural strength of GROUP I and GROUP II samples was 145.43 MPa and 112.57 MPa. The colour difference between GROUP I and GROUP II samples ΔE was 2.89. Conclusions: PMMA heat polymerized denture base resin incorporated with EDTA exhibited antifungal properties and a minimum reduction in flexural strength, with a perceptible color difference. This modified PMMA resin is recommended for implant overdentures.