In vitro antimicrobial effects of green tea, microwaving, cold boiled water, and chlorhexidine on Streptococcus mutans and Candida albicans on silicone pacifiers

Abstract

Background: This study aimed to compare the antimicrobial effects of green tea, microwaving,
cold boiled water, and chlorhexidine (CHX) on Streptococcus mutans and Candida albicans on
silicone pacifiers.
Materials and Methods: In this in vitro experimental study, 60 equal‑size samples of silicone
pacifiers were cut, ultraviolet sterilized, and randomly divided into two groups (n = 30) for immersion
in 0.5 McFarland standard suspension of S. mutans and C. albicans. The samples in each group were
then randomly divided into five subgroups (n = 6) for disinfection with 0.12% CHX, cold boiled
water, green tea, microwaving for 7 min, and distilled water. The sample suspensions were cultured
on blood agar (for S. mutans) and Sabouraud dextrose agar (for C. albicans) and incubated. The
number of colonies was counted after 24 and 48 h. Data were analyzed using the Kruskal–Wallis
and Mann–Whitney tests (P < 0.05).
Results: At 24 and 48 h, the S. mutans colony count was the lowest in CHX and green tea subgroups
followed by microwave, cold boiled water, and distilled water subgroups (P < 0.05).
Conclusion: CHX and green tea can significantly decrease the S. mutans and C. albicans colony
count on silicone pacifiers.
Key Words: Candida albicans, chlorhexidine, microwaves, pacifiers, Streptococcus mutans