Korean J Dent Mater.  2023 Dec;50(4):267-280. 10.14815/kjdm.2023.50.4.267.

The effect of polishing procedure and pH on the color change of denture base resin.

• Kim JH
• Kim JW
• Hwang SY
• Kim HJ

• KMID: 2550712
• DOI: http://doi.org/10.14815/kjdm.2023.50.4.267

Abstract

The purpose of this study is to investigate the effect of polishing procedure and pH on the color change of denture base resin. Heat-cured denture resin specimens (10 x 10 x 4 mm) were prepared with three surface roughness levels: G0 (non-polished), G1 (polished with acrylic carbide bur, silicone rubber points and brush wheel), G2 (additional polishing and buffing with lathe, pumice and rouge compound). Each specimen of G0, G1, G2 was immersed in a staining solution with four different acidic conditions (pH 2, pH 4, pH7, pH 9.18) for 14 days. Surface roughness (Ra) was measured with AFM (atomic force microscope) and the surface was inspected with a digital microscope. Color change (∆E*) was quantified using a spectrophotometer in CIE Lab color space. After immersion, inspection with the digital microscope showed most stain in G0, followed by G2 and G1. G0 have shown significantly higher color change (∆E*) after immersion than G1 and G2 in different pH solutions other than pH 9.18. In the results of the color change estimation in each group with different pH solutions, all groups showed the least color change in pH 9.18 solution. The highest color change after immersion was observed in G0, pH 7.0 solution and G0, pH 2.0 solution (P<0.05). G1 and G2 showed no significant color change among different pH solutions (P>0.05). Denture base resin specimen with higher surface roughness showed more significant color change after immersion compared to specimen with lower surface roughness. More significant color changes were observed after immersion in acidic and neutral pH solution than in alkaline solution.

Keyword

Heat-curing resin; Polishing procedure; pH; Surface roughness; Color change; Color stability