Evaluation of the Effects of 70% Ethanol and Formalin Tablets on Dental Anesthesia Cartridges

Ershad  Hemmati; Zeinab  Shanehsaz; Mohammad  Hashemzadeh; Alireza  Amirkhani; Faeze Valian  Baghgandomi

doi:10.18502/ssu.v33i8.20049

Ershad Hemmati Department of Oral and Maxillofacial surgery, Faculty of Dentistry, Ahvaz Jondishapur University of Medical Sciences, Ahvaz, Iran.
Zeinab Shanehsaz Department of Periodontics, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Mohammad Hashemzadeh Department of Microbiology, School of Medicine, Ahvaz Jondishapur University of Medical Sciences, Ahvaz, Iran.
Alireza Amirkhani Department of Prosthodontics, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Faeze Valian Baghgandomi Department of Periodontics, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.

DOI: https://doi.org/10.18502/ssu.v33i8.20049

Keywords: Disinfectant, Dentistry, Anesthesia cartridge.

Abstract

Introduction: Selection the appropriate disinfectant can play an effective role in reducing infection caused by contamination of the external surface of anesthetic cartridges. Therefore, the present study aimed to investigate the effects of different disinfectants on dental anesthetics and their effect on microbial contamination of dental anesthetics.

Methods: In this laboratory study, nine carpules from each of three different brands were obtained for the study. A subset of these carpules served as a control group, undergoing microbial culture without any disinfection to evaluate initial microbial contamination. The remaining carpules were subjected to 70% ethanol or formalin, and then underwent microbial culture to assess the efficacy of these disinfectants. These procedures were conducted in the Microbiology Department Laboratory of the Faculty of Medicine. Subsequently, the carpules were transferred to the School of Pharmacy to evaluate the penetration of 70% ethanol and formalin. Using the high‑performance liquid chromatography (HPLC) technique, disinfectant penetration levels inside the carpules were measured after 24 hours. The data were entered into SPSS16 and analyzed using the Kruskal–Wallis statistical test.

Results: Two out of nine undisinfected carpules showed positive microbial cultures. In comparison, all 18 disinfected cartridges tested negative for microbial growth after 24 hours. Statistical analysis revealed significant differences in the measured amounts of formalin (P=0.0036) and ethanol (P=0.0037). Specifically, Spanish carpules contained the lowest amounts, whereas Colombian and Iranian carpules showed the highest concentrations of formalin and alcohol.

Conclusion: The results of this study showed that dental anesthesia carpules can be contaminated with bacteria, and their commercial packaging does not guarantee complete sterility. The use of 70% ethanol and formalin tablets effectively eliminated these contaminations without causing any significant toxic effects.