A comparison of the efficacy of mechanical, chemical, and microwave radiation methods in disinfecting complete dentures

Abstract

Background:Poor denture hygiene can be a potential source of systemic diseases. The aim of this study was to compare the efficacy of microwave radiation with that of chemical and mechanical techniques in disinfecting complete dentures contaminated with Staphylococcusaureusand Pseudomonasaeruginosa.

MaterialsandMethods: Seventy-two sterilized mandibular dentures were separately contaminated with S.aureus (n = 32) and P.aeruginosa(n = 32) and then incubated at 37°C for 48 h. The contaminated dentures were disinfected as follows: chemical disinfection with Corega tablets; chemical disinfection with 2% glutaraldehyde; mechanical disinfection by brushing the denture; and physical disinfection by irradiating with 650-W for 3 min microwaves with six samples in each subgroup. Six dentures served as negative control group, and six contaminated dentures with no disinfection served as the positive control group. 10^-3‒10^-6 dilutions were cultured in the nutrient agar, with colonies counted after incubation at 37°C for 48 h. To evaluate long-term disinfection, the containers with nutrient agar and dentures were stored for 7 days at 37°C to evaluate turbidity. Data were analyzed using Kruskal–Wallis and Mann–Whitney U-test (α = 0.05).

Results: There was no evidence of bacterial growth at 48 h and turbidity after 7 days of incubation of dentures disinfected by microwaves, glutaraldehyde, and Corega tablets, which was statistically significant compared to the positive controls (P< 0.001). In mechanically disinfected dentures (brushing), bacterial growth was detected after 48 h which was statistically significant compared to the positive controls (P< 0.001) and turbidity was seen in all the nutrient agar plates.

Conclusion: Microwave radiation, 2% glutaraldehyde, and Corega tablets disinfected complete dentures contaminated with S.aureusand P.aeruginosain the long and short terms.

Key Words: Glutaraldehyde , microwaves, Pseudomonasaeruginosa,Staphylococcusaureus