In vitro study of the Ferric sulfate and Formocresol antibacterial effect on Oral bacteria

Today, pulpotomy using ferric sulfate has become more popular because of the side effects of formocresol. This study was conducted to investigate the antibacterial effect of  ferric sulfate and formocresol on Streptococcus mutans, Lactobacillus acidophilus, and Enterococcus faecalis.

 The antibacterial effect of  ferric sulfate and formocresol (two types) on oral bacteria was investigated using the  disk agar diffusion method. We had four groups for each effective combination. However, each experiment was performed in triplicate, and chlorhexidine 0.2% was used as a control antimicrobial agent. After collecting data using (SPSS 26) software, it was analyzed using Kruskal-Wallis and Mann-Whitney tests at an error level less than and equal to 0.05.

The most antibacterial effect was related to formocresol. However, the diameter of the no-growth zone of Streptococcus mutans, Lactobacillus acidophilus, and Enterococcus faecalis under the influence of type 1-formocresol (nikDarman®,Made in Iran) was 70, 72, 50 mm, and in type 2 (MasterDent® Made in USA) it was 72, 76, and 54 mm. Also,  ferric sulfate was less effective than chlorhexidine, while the diameter of the no-growth  zone of Streptococcus mutans, Lactobacillus acidophilus, and Enterococcus faecalis under the influence of  ferric sulfate(Astringedent_Ultradent®,Made in USA) was 12, 24, and 12 mm, respectively. And for 0.2% chlorhexidine(Irsha®,Made in IRAN), it was 22, 26, and 24 mm, respectively.

The antibacterial effect of formocresol was much higher than ferric sulfate and chlorhexidine on streptococcus mutans, Lactobacillus acidophilus, and Enterococcus faecalis