In Vitro Efficacy of Domestic Techniques for Disinfection of Toothbrushes Contaminated With Enterococcus faecalis

Abstract

Introduction: Oral hygiene education for patients is fundamental in preventive-promotional dentistry. The disinfection of toothbrushes (TBs) must be integrated into this context due to their proximity to contaminant sources that make them vulnerable to cross infection in homes. The objective of this study was to compare the efficacy of domestic techniques for disinfection of TBs. Materials and Methods: We performed an in vitro study of 76 TBs contaminated with Enterococcus faecalis (Ef) ATCC 29212 subjected to different disinfection protocols: G1. Distilled water (DW; negative control; n = 8), G2. Dimethylsulfoxide (DMSO)10% (negative control; n = 8), G3. Chlorhexidine (CHX) 0.12% (positive control; n = 15), G4. 100% white vinegar (WV; n = 15), G5. Microwave (MW) at 700 W (n = 15), and G6. 200 mg/mL of certified alcoholic extract of purple garlic (GARLIC) from Arequipa (Allium sativum L; n = 15). Bacterial count was assessed by colony-forming units (CFU/mL) categorized as contamination: low (<30), medium (30-300), and high (>300). The Kruskal-Wallis test with post hoc pairs was used at a significance level of p < 0.05. Results: Efficacy against Ef showed highly significant differences between groups (p < 0.001) with lower median CFU/mL in G3 and G4 (Me = 0 [IQR (interquartile range) = 0]: low) and G5 (Me = 6000 [IQR = 45,000]: low/medium) versus negative controls (Me = 378,500 and 5,020,000 [IQR = 4,605,000 and 6,760,000]: medium/high; p ≤ 0.019). The counts of the G5 were not statistically different than G3, G4, and G6 (p > 0.06). The G6 (Me = 1,510,000 [IQR = 590,000]: medium) was inferior to G3 and G4 (p < 0.001), but similar to both negative control groups (p > 0.999). Conclusions: Disinfection of TBs with CHX, WV, and MWs produces a significant effective reduction in the count of Ef.

Keywords: Allium sativum; disinfection; microwave; toothbrush; vinegar.

Figure 1

Flowchart of the TB disinfection experiment. TB, toothbrush.

Figure 2

Level of Ef contamination in the different disinfection groups. CHX, Chlorhexidine; DMSO, dimethylsulfoxide; DW, distilled water; Ef, Enteroccocus faecalis; GARLIC, garlic alcohol extract, MW, microwave; WV, white vinegar.