Influence of chlorine dioxide on the physical properties of denture base materials

Takuya Shinhara, DDS,a Takeshi Maeda, DDS, PhD,a Guang Hong, MD, DDS, PhD,b Hiroshi Nishizaki, DDS, PhD,a and Joji Okazaki, DDS, PhDa

aDepartment of Removable Prosthodontics and Occlusion, Osaka Dental University, Hirakata, Japan, and bLiason Center for Innovative Dentistry, Graduate School of Dentistry, Tohoku University, Sendai, Japan

Purpose: The purpose of this study was to determine the influence of chlorine dioxide (ClO2) on the physical properties of commercial denture base materials.
Materials and Methods: One heat-polymerized denture base acrylic resin and three metallic materials; gold-silver-palladium alloy, pure titanium, and cobalt-chromium (Co-Cr) alloy, were used in the study. Three types of commercial denture cleansers Polident (POL), Pika (PIK), and Kirari (KIR) were used. And ClO2 was used at the following three concentrations: 1, 10, and 100 ppm. The flexural strength and flexural modulus of denture base resin were measured using universal testing machine. And the colour stability and surface morphology of dental metal materials were measured using colorimeter and scanning electron microscope.
Results: Flexural strength of the resin blocks was 70 MPa or more for all denture cleanser after 90 days of immersion. The flexural modulus was greater than 2,000 MPa specified in ISO standards for all test specimens. The specimens of Co-Cr immersed in ClO2 exhibited high values after immersing for 90 days at 10 ppm and for all immersing times at 100 ppm concentration.
Conclusion: The following conclusions were drawn: 1) low concentrations of ClO2 cause less discoloration than commercially available denture cleansers; and 2) low concentrations of ClO2 are suitable for use as denture cleanser.
(Asian Pac J Dent 2013; 13: 27-35.)
Key Words: chlorine dioxide, denture base resin, denture cleanser, metallic material