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VOLUME 23 , ISSUE 3 ( March, 2022 ) > List of Articles


Evaluation of a Rapid Biological Spore Test for Dental Instrument Sterilization

Thomas E Rams, Jacqueline D Sautter, Andie H Lee, Arie J van Winkelhoff

Keywords : Bacterial spores, Dental infection control, Dental instruments, Steam autoclave, Sterilization

Citation Information : Rams TE, Sautter JD, Lee AH, van Winkelhoff AJ. Evaluation of a Rapid Biological Spore Test for Dental Instrument Sterilization. J Contemp Dent Pract 2022; 23 (3):279-283.

DOI: 10.5005/jp-journals-10024-3317

License: CC BY-NC 4.0

Published Online: 24-06-2022

Copyright Statement:  Copyright © 2022; The Author(s).


Aim: This study evaluated the reliability of a new rapid biological spore test (BST) for determining the sterilization efficacy of dental steam autoclaves within 20 minutes, as compared to a conventional BST requiring 2 days of incubation after autoclave exposure. Materials and methods: A total of 177 pairs of BST, each composed of a rapid test (Celerity™ 20 Steam Biologic Indicator, Steris) and a conventional BST (Attest™ 1262 Biological Indicator, 3M), both containing Geobacillus stearothermophilus spores, were placed into steam autoclaves loaded with instruments, and subjected to either sterilizing (157 pairs) or non-sterilizing conditions (20 pairs). Celerity™ BST was then incubated for 20 minutes at 57°C, with the growth medium evaluated spectrophotometrically for fluorescent α-glucosidase signal changes (no change with successful sterilization; increased fluorescence after failed sterilization). Attest™ BST was incubated for 48 hours at 57°C, after which a pH-based color change in the culture broth was visually assessed (no change in purple color with successful sterilization; change to yellow color with failed sterilization). Results: Celerity™ and Attest™ BST both accurately identified successful sterilization, with no G. stearothermophilus spore growth from either BST after exposure to sterilizing steam autoclave conditions (100% agreement between 157 pairs of each BST). Both BST also accurately detected unsuccessful sterilization, with all tested ampoules positive for G. stearothermophilus spore germination after non-sterilizing steam autoclave time periods. Both BST exhibited 100% sensitivity, specificity, and accuracy for detection of sterilizing steam autoclave conditions. Conclusion: Celerity™ BST, after only 20 minutes incubation, performed equally as well as a BST requiring 48 hours incubation in determining the sterilization efficacy of dental steam autoclaves. Clinical significance: Rapid BST offer earlier detection of sterilization failure before potentially contaminated dental instruments are used in clinical patient care.

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  1. Fulford MR, Stankiewicz NR. Sterilisation in dentistry. In: Fulford MR, Stankiewicz NR, editors. Infection control in primary dental care. Cham: Springer Nature Switzerland AG; 2020. p. 77–88.
  2. Sebastiani FR, Dym H, Kirpalani T. Infection control in the dental office. Dent Clin North Am 2017;61(2):435–457. DOI: 10.1016/j.cden.2016.12.008.
  3. Fulford MR, Stankiewicz NR. A history of infection control. In: Fulford MR, Stankiewicz NR, editors. Infection control in primary dental care. Cham: Springer Nature Switzerland AG; 2020. p. 1–10.
  4. Redd JT, Baumbach J, Kohn W, et al. Patient-to-patient transmission of hepatitis B virus associated with oral surgery. J Infect Dis 2007;195(9):1311–1314. DOI: 10.1086/513435.
  5. Weaver JM. Confirmed transmission of hepatitis C in an oral surgery office. Anesth Prog 2014;61(3):93–94. DOI: 10.2344/0003-3006-61.3.93.
  6. Volgenant CMC, de Soet JJ. Cross-transmission in the dental office: does this make you ill? Curr Oral Health Rep 2018;5(4):221–228. DOI: 10.1007/s40496-018-0201-3.
  7. Skaug N, Lingaas E, Nielsen O, et al. Biological monitoring of sterilizers and sterilization failures in Norwegian dental offices in 1985 and 1996. Acta Odontol Scand 1999;57(4):175–180. DOI: 10.1080/000163599428733.
  8. Miller CH. Use of spore tests for quality assurance in infection control. Am J Dent 2001;14(2):114. PMID: 11507798.
  9. McMullan G, Christie JM, Rahman TJ, et al. Habitat, applications and genomics of the aerobic, thermophilic genus Geobacillus. Biochem Soc Trans 2004;32(Pt 2):214–217. DOI: 10.1042/bst0320214.
  10. Feeherry FE, Munsey DT, Rowley DB. Thermal inactivation and injury of Bacillus stearothermophilus spores. Appl Environ Microbiol 1987;53(2):365–370. DOI: 10.1128/aem.53.2.365-370.1987.
  11. Hughes C, Socola G, Hughes M. The gold standard in sterilizer monitoring. Mater Manag Health Care 2009;18(2):23–25. PMID: 19288678.
  12. American Dental Association. Biological indicators for verifying sterilization. J Am Dent Assoc 1988;117(5):653–654. PMID: 3147289.
  13. American Dental Association. Infection control recommendations for the dental office and the dental laboratory. J Am Dent Assoc 1996;127(5):672–680. DOI: 10.14219/jada.archive.1996.0280.
  14. Kohn WG, Collins AS, Cleveland JL, et al. Guidelines for infection control in dental health-care settings–2003. MMWR Recomm Rep 2003;52(RR-17):1–61. PMID: 14685139.
  15. Panta G, Richardson AK, Shaw IC. Effectiveness of autoclaving in sterilizing reusable medical devices in healthcare facilities. J Infect Dev Ctries 2019;13(10):858–864. DOI: 10.3855/jidc.11433.
  16. Rutala WA, Jones SM, Weber DJ. Comparison of a rapid readout biological indicator for steam sterilization with four conventional biological indicators and five chemical indicators. Infect Control Hosp Epidemiol 1996;17(7):423–428. DOI: 10.1086/647333.
  17. Palenik CJ, Burke FJ, Coulter WA, et al. Improving and monitoring autoclave performance in dental practice. Br Dent J 1999;187(11):581–584. DOI: 10.1038/sj.bdj.4800338.
  18. Steris Corporation. Technical data monograph – Celerity™ 20 Steam biological indicators. Mentor (OH): Steris Corporation; 2021. p. 1–22. Available from:
  19. Dhand NK, Khatkar MS. Statulator: an online statistical calculator. Sample size calculator for comparing two paired proportions. 2014 [Accessed May 7, 2022]. Available from:
  20. Shaikh SA. Measures derived from a 2 × 2 table for an accuracy of a diagnostic test. J Biomet Biostat 2011;2(5):1000128. DOI: 10.4172/2155-6180.1000128.
  21. Vesley D, Nellis MA, Allwood PB. Evaluation of a rapid readout biological indicator for 121 degrees C gravity and 132 degrees C vacuum-assisted steam sterilization cycles. Infect Control Hosp Epidemiol 1995;16(5):281–286. DOI: 10.1086/647108.
  22. Setlow B, Korza G, Setlow P. Analysis of α-glucosidase enzyme activity used in a rapid test for steam sterilization assurance. J Appl Microbiol 2016;120(5):1326–1335. DOI: 10.1111/jam.13074.
  23. Ritchie DL, Barria MA. Prion diseases: a unique transmissible agent or a model for neurodegenerative diseases? Biomolecules 2021;11(2):207. DOI: 10.3390/biom11020207.
  24. Casolari A. Heat resistance of prions and food processing. Food Microbiol 1998;15(1):59–63. DOI: 10.1006/fmic.1997.0141.
  25. Fernie K, Steele PJ, Taylor DM, et al. Comparative studies on the thermostability of five strains of transmissible-spongiform-encephalopathy agent. Biotechnol Appl Biochem 2007;47(Pt 4):175–183. DOI: 10.1042/BA20060249.
  26. Vassey M, Budge C, Poolman T, et al. A quantitative assessment of residual protein levels on dental instruments reprocessed by manual, ultrasonic and automated cleaning methods. Br Dent J 2011;210(9):E14. DOI: 10.1038/sj.bdj.2011.144.
  27. Kirby E, Dickinson J, Vassey M, et al. Bioassay studies support the potential for iatrogenic transmission of variant Creutzfeldt Jakob disease through dental procedures. PLoS One 2012;7(11):e49850. DOI: 10.1371/journal.pone.0049850.
  28. Ruegger J, Stoeck K, Amsler L, et al. A case-control study of sporadic Creutzfeldt-Jakob disease in Switzerland: analysis of potential risk factors with regard to an increased CJD incidence in the years 2001-2004. BMC Public Health 2009;9:18. DOI: 10.1186/1471-2458-9-18.
  29. Walker JT, Dickinson J, Sutton JM, et al. Implications for Creutzfeldt-Jakob disease (CJD) in dentistry: a review of current knowledge. J Dent Res 2008;87(6):511–519. DOI: 10.1177/154405910808700613.
  30. Molesworth AM, Smith AJ, Everington D, et al. Risk factors for variant Creutzfeldt-Jakob disease in dental practice: a case-control study. Br Dent J 2012;213(11):E19. DOI: 10.1038/sj.bdj.2012.1089.
  31. Sushma B, Gugwad S, Pavaskar R, et al. Prions in dentistry: a need to be concerned and known. J Oral Maxillofac Pathol 2016;20(1):111–114. DOI: 10.4103/0973-029X.180961.
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