The Index of Microbial Air contamination in dental clinics: A review and meta-analysis
Keywords:
air, dental clinic, IMA standard, microbial contamination, monitoring, passive samplingAbstract
Background and aim. In dental clinics, the risk of airborne infection is relevant. Active and passive sampling can be used to assess microbial air contamination. Passive sampling has been standardised by the Index of Microbial Air Contamination (IMA). This study aimed to review the use of the IMA standard for air quality assessment in dental clinics, before, during and after dental procedures, and to conduct a meta-analysis of the obtained values.
Methods. Scopus, PubMed, and Web of Science were analyzed for articles published until 2024, citing “Pasquarella C., et al., The index of microbial air contamination. J Hosp Infect 2000”. Only original studies, in English or Italian, performed in dental clinics and applying the IMA standard were included in the review.
Results. After applying the inclusion criteria, nine studies were considered. The mean IMA values before, during, and after dental procedures ranged from 2.4 to 38.3, 19 to 53.3, and 13 to 20, respectively. Seven studies were included in the meta-analysis, which yielded mean IMA values of 15.4, 32.7, and 16.7, before, during and after dental activity, respectively. Considering only the study performed in Europe, a value of 29 IMA during the dental activity was obtained.
Conclusions. This review has given a picture of the use of the IMA standard in dental clinics. The meta-analysis yielded IMA values, before, during and after clinical practice, which could be valuable in clinical practice. Due to the ease of use, low cost, and comparability of results, the IMA standard is recommended for the routine monitoring of microbial air contamination (www.actabiomedica.it).
References
1. Centers for Disease Control and Prevention. Guidelines for Infection Control in Dental Health-Care Settings 2003, updated: July 2019.
https://www.cdc.gov/mmwr/pdf/rr/rr5217.pdf. Accessed October 15, 2024.
2. Centers for Disease Control and Prevention. Summary of Infection Prevention Practices in Dental Settings: Basic Expectation for Safe Care. Atlanta, GA: Centers for Disease Control and Prevention, US Dept of Health and Human Services 2016.
https://www.cdc.gov/dental-infection-control/media/pdfs/2024/07/safe-care2.pdf?CDC_AAref_Val=https://www.cdc.gov/oralhealth/infectioncontrol/pdf/safe-care2.pdf. Accessed October 15, 2024.
3. Cole EC. Cook CE. Characterization of infectious aerosols in healthcare facilities: an aid to effective engineering controls and preventive strategies. Am J Infect Control 1998;26:453-464.
4. Kumbargere Nagraj S, Eachempati P. Paisi M, Nasser M, Sivaramakrishnan G, Verbeek JH. Interventions to reduce contaminated aerosols produced during dental procedures for preventing infectious diseases. Cochrane Database Syst Rev 2020;10(10):1-122.
5. Kumbargere Nagraj S, Eachempati P, Paisi, M, Nasser M, Sivaramakrishnan, G, Francis T, Verbeek JH. Preprocedural mouth rinses for preventing transmission of infectious diseases through aerosols in dental healthcare providers. Cochrane Database Syst Rev 2022;8:1-122.
6. Laheij AM, Kistler JO, Belibasakis GN, Välimaa H, de Soet JJ. European Oral Microbiology Workshop (EOMW). Healthcare-associated viral and bacterial infections in dentistry. J Oral Microbiol 2012;4.
7. Van der Weijden F. Aerosol in the oral health-care setting: a misty topic. Clin Oral Investig 2023; 27:23-32.
8. Zemouri C, de Soet H, Crielaard W, Laheij A. A scoping review on bioaerosols in healthcare and the dental environment. PLoS ONE 2017;12.
9. Centers for Disease Control and Prevention. Guidelines for Environmental infection Control in Health-Care Facilities. Recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee (HICPAC). 2003.
https://www.cdc.gov/infection-control/media/pdfs/Guideline-Environmental-H.pdf. Accessed October 15, 2024.
10. Pankhurst CL, Coulter WA. Do contaminated dental unit waterlines pose a risk of infection? J Dentistry 2007;35:712-720.
11. Pasquarella C, Veronesi L, Napoli C, Castiglia P, Liguori G, Rizzetto R, Montagna MT, Rizzetto R, Torre I, Righi E, Farruggia P, Tesauro M, Torregrossa MV, Montagna MT, Colucci ME. Microbial environment contamination in Italian dental clinics: A multicenter study yielding recommendations for standardized sampling methods and threshold values. Sci Total Environ 2012;420: 289-299.
12. Rautemaa R, Nordberg A, Wuolijoki-Saaristo K, Meurman JH. Bacterial aerosols in a dental practice - a potential hospital infection problem? 2006;64:76-81.
13. Szymanska J. Dental bioaerosols as an occupational hazard in a dentist’s workplace. Ann Agric Environ Med 2007;14:203-207.
14. Castiglia P, Liguori G, Montagna MT, Napoli C, Pasquarella C, Bergomi M, Fabiani L, Monarca S, Petti S. Italian multicenter study on infection hazards during dental practice: control of environmental microbial contamination in public dental surgeries. BMC Public Health 2008;8: 187-193.
15. Harrel SK, Molinari J. Aerosols and splatter in dentistry: a brief review of the literature and infection control implications. J Am Dent Assoc 2004;135(4):429-437.
16. King TB, Muzzin KB, Berry CV, Anders LM. The effectiveness of an aerosol reduction device for ultrasonic scalers. J Periodontol 1997;68:45-49.
17. Puljich A, Jiao K, Lee RS, Walsh LJ, Ivanovski S, Han P. Simulated and clinical aerosol spread in common periodontal aerosol-generating procedures. Clin Oral Investig 2022;26:5751-5762.
18. Timmerman MF, Menso L, Steinfort J, van Winkelhoff AJ, van der Weijden GA. Atmospheric contamination during ultrasonic scaling. J Clin Periodontol 2004;31:458-462.
19. Kadailcifer DG, Cotuk A. Microbial contamination of dental unit waterlines and effect on quality of indoor air. Environ Monit Assess 2014;186:3431-3444.
20. Szymanska J. Biofilm and dental unit waterlines. Ann Agric Environ Med 2003;10(2):151-7.
21. Szymańska J, Sitkowska J. Bacterial contamination of dental unit waterlines. Environ Monit Assess 2013;185(5):3603-11.
22. Allsopp J, Basu MK, Browne RM, Burge PS, Matthews JB. Survey of the use of personal protective equipment and prevalence of work-related symptoms among dental staff. Occup Environ Med 1997;54:125-134.
23. Araujo MW, Andreana S. Risk and prevention of transmission of infectious diseases in dentistry. Quintessence Int 2002;33:376-382.
24. Polednik B. Exposure of staff to aerosols and bioaerosols in a dental office. Building and Environment 2021;187:107-388.
25. Bahador M, Alfirdous RA, Alguria TA, Griffin I, Tordik PA, Martinho FC. Aerosols generated during endodontic treatment: a special concern during the Coronavirus Disease 2019 Pandemic. J Endod 2019;47:732-739.
26. Manea A, Crisan D, Baciut G, Baciut M, Bran S, Armencea G, Crisan M, Colosi H, Colosi I, Vodnar D, Aghorghiesei A, Aghorghiesei O. The importance of atmospheric microbial contamination control in dental offices: Raised awareness caused by the SARS-CoV-2 Pandemic. Appl Sci 2021;11: 2359.
27. Ralli M, Candelori F, Cambria F, Greco A, Angeletti D, Lambiase A, Campo F, Minni A, Polimeni A, De Vincentiis M. Impact of COVID-19 pandemic on otolaryngology, ophthalmology and dental clinical activity and future perspectives. Eur Rev Med Pharmacol Sci 2020;24:9705-9971.
28. Suprono MS, Savignano R, Won JB, Lillard S, Zhong Z, Ahmed A, Roque-Torres G, Zhang W, Oyoyo UB, Richardson P, Caruso J, Handysides R, Li Y. Evaluation of microbial air quality and aerosol distribution in a large dental clinic. Am J Dent 2022;35(5):268-272.
29. Wood D, Da Silva K. A review of infection prevention and control guidelines for dental offices during the COVID-19 pandemic in mid-2020. Canadian Journal of Infection Control 2021;36(3): 129-137.
30. Li Y, Leung GM, Tang JW, Yang X, Chao CH, Lin JZ, Lu JW, Nielsen PV, Niu J, Qian H, Sleigh AC, Su HJ, Sundell J, Wong TW, Yuen PL. Role of ventilation in airborne transmission of infectious agents in the built environment - a multidisciplinary systematic review. Indoor Air 2007;17:2-18.
31. EN 17141:2020. Cleanrooms and associated controlled environments - Biocontamination control.
32. ISO 14698-1:2003. Cleanrooms and associated controlled environments biocontamination control. Part 1: general principles and methods.
33. Pasquarella C, Albertini R, Dall’Aglio P, Saccani E, Sansebastiano GE, Signorelli C. Air microbial sampling: The state of the art. Ig San Pubbl 2008;64:79–120.
34. Pitzurra M, Savino A, Pasquarella C. Microbiological environment monitoring (MEM). Ann Ig 1997;9:439–454.
35. Whyte W, Thomas AM. Auditing the microbiological quality of the air in operating theatres. Bone Joint J 2024;106-B(9):887-891.
36. Viani I, Colucci ME, Pergreffi M, Rossi D, Veronesi L, Bizzarro A, Capobianco E, Affanni P, Zoni R, Saccani E, Albertini R, Pasquarella C. Passive air sampling: the use of the index of microbial air contamination. Acta Biomed 2020;91:92-105.
37. Dybwad M, Skogan G, Blatny JM. Comparative Testing and Evaluation of Nine Different Air Samplers: End-to-End Sampling Efficiencies as Specific Performance Measurements for Bioaerosol Applications. Aerosol Science and Technology 2014;48:282-295.
38. Whyte W, Green G, Albisu A. Collection efficiency and design of microbial air samplers. Journal of Aerosol Science 2007;38(1):97-110.
39. Pasquarella C, Pitzurra O, Savino A. The index of microbial air contamination. J Hosp Infect 2000;46:241–256.
40. R Development Core Team. A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria 2024.
41. Aquino de Muro M, Shuryak I, Uhlemann AC, Tillman A, Seeram D, Zakaria J, Welch D, Erde SM, Brenner DJ. The abundance of the potential pathogen Staphylococcus hominis in the air microbiome in a dental clinic and its susceptibility to far-UVC light. MicrobiologyOpen 2023;12.
42. Decraene V, Ready D, Pratten J, Wilson M. Air-borne microbial contamination of surfaces in a UK dental clinic. J Gen Appl Microbiol 2008;54:195-203.
43. Kherdekar RS, Dixit A, Kothari A, Pandey KP, Advani H, Gaurav A, Omar BJ. Unusually isolated Staphylococcus arlettae in intra-oral sutures - Case series. Access Microbiol 2023;5.
44. Manarte-Monteiro P, Carvalho A, Pina C, Olivira H, Conceicao Manso M. Air quality assessment during dental practice: Aerosols bacterial counts in an universitary clinic. Rev Port Estomatol Med Dent Cir Maxillofac 2013;54:2-7.
45. Montalli VAM, Garcez AS, de Oliveira LVC, Sperandio M, Napimoga MH, Motta RHL. A novel dental biosafety device to control the spread of potentially contaminated dispersion particles from dental ultrasonic tips. PLoS One 2021;6(2).
46. Pasquarella C, Veronesi L, Castiglia P, Liguori G, Montagna MT, Napoli C, Rizzetto R, Torre I, Masia MD, Di Onofrio V, Colucci ME, Tinteri C, Tanzi M. Italian multicentre study on microbial environmental contamination in dental clinics: a pilot study. Sci Total Environ 2010;408:4045-4051.
47. Shanmugaraj GB, Rao A. A study to assess the microbial profile and index of microbial air contamination in dental operatories. Indian J Dent Res 2020;31:465-469.
48. Vieira CD, De Carvalho MA, De Resende MA, De Menezes Cussiol NA, Alvarez-Leite ME, Dos Santos SG, de Oliveira MB, De Magalhães TF, Silva MX, Nicoli JR, de Macêdo Farias L. Isolation of clinically relevant fungal species from solid waste and environment of dental health services. Lett Appl Microbiol 2010;51:370-376.
49. Zemouri C, Volgenant CMC, Buijs MJ; Crielaard W, Rosema NAM, Brandt BW, Laheij AMGA, De Soet JJ. Dental aerosols: microbial composition and spatial distribution. J Oral Microbiol 2020;12:1762040.
50. Cellini L, Di Campli E, Di Candia M, Chiavaroli G. Quantitative microbial monitoring in a dental office. Public Health 2001;115:301-305.
51. Guida M, Gallé F, Di Onofrio V, Nastro RA, Battista M, Liguori R, Battista F, Liguori G. Environmental microbial contamination in dental setting: a local experience. J Prev Med Hyg 2012;53:207-212.
52. Hossein M, Hossein K, Mojtaba S, Davood E. Relation of bacteriological water and air quality in dentistry center. J Pure Appl Microbiol 2014;8: 681-692.
53. Petti S, Iannazzo S, Tarsitani G. Comparison between different methods to monitor the microbial level of indoor air contamination in the dental office. Ann Ig 2003;15:725-733.
54. Tellier R, Li Y, Cowling BJ, Tang JW. Recognition of aerosol transmission of infectious agents: a commentary. BMC Infect Dis 2019;19:101.
55. Kedjarune U, Kukiattrakoon B, Yapong B, Chowanadisai S, Leggat P. Bacterial aerosols in the dental clinic: effects of time, position and type of treatment. Int Dent J 2000;50:103-107.
56. Pasquarella C, Vitali P, Saccani E, Manotti P, Boccuni C, Ugolotti M, Signorelli C, Mariotti F, Sansebastiano GE, Albertini R. Microbial air monitoring in operating theatres: experience at the University Hospital of Parma. J Hosp Infect 2012;81(1):50-7.
57. Agodi A, Auxilia F, Barchitta M, Cristina ML, D'Alessandro D, Mura I, Nobile M, Pasquarella C. Italian Study Group of Hospital Hygiene. Operating theatre ventilation systems and microbial air contamination in total joint replacement surgery: results of the GISIO-ISChIA study. J Hosp Infect 2015;90:213-219.
58. Cristina ML, Spagnolo AM, Ottria G, Schinca E, Dupont C, Carbone A, Oliva M, Sartini M. Microbial Air Monitoring in Turbulent Airflow Operating Theatres: Is It Possible to Calculate and Hypothesize New Benchmarks for Microbial Air Load? Int J Environ Res Public Health 2021:18(19):10379.
59. Veronesi L, Colucci ME, Napoli C, Castiglia P, Liguori G, Torre I, Righi E, Farruggia P, Tesauro M, Montagna MT, Gallè, F, Masia MD, Di Onofrio V, Caggiano G, Tinteri C, Panico M, Pennino F, Cannova, L, Pasquarella C. Air microbial contamination in dental clinics: comparison between active and passive methods. Acta Biomed 2020;91(3-S):165-167.
60. Perdelli F, Sartini M, Orlando M, Secchi V, Cristina Ml. Relationship between settling microbial load and suspended microbial load in operating rooms. Ann Ig 2000;12:373-380.
61. European Commission. EU Guidelines to Good Manufacturing Practice Medicinal Products for Human and Veterinary Use Revision to Annex 1. Manufacture of Sterile Medicinal Products 2022.
https://health.ec.europa.eu/system/files/2022-08/20220825_gmp-an1_en_0.pdf Accessed August 8, 2024.
62. Napoli C, Marcotrigiano V, Montagna MT. Air sampling procedures to evaluate microbial contamination: a comparison between active and passive methods in operating theatres. BMC Public Health 2012;2:12, 594.
63. Orpianesi C, Cresci A, La Rosa F, Saltalamacchia G, Tarsi R. Evaluation of microbial contamination in a hospital environment. Comparison between the Surface Air System and the traditional method. Nuovi Ann Ig Microbiol 1983;34:171-185.
64. Pitzurra M, Morlunghi P. Contaminazione microbica dell’aria atmosferica: correlazione fra due diverse metodiche di rilevazione. Ig Mod 1978;71:490-502.
65. Verhoeff AP, van Wijnen JH, Bolej JS, Brunekreef B, van Reenen-Hoekstra ES, Samson RA. Enumeration and identification of airborne viable mould propagules in houses. A field comparison of selected techniques. Allergy 1990;45: 275-284.
66. Whyte W. Sterility assurance and models for assessing airborne bacterial contamination. Parenter Sci Technol 1986;40:188–97.
67. Chawla H, Anand P, Garg K, Bhagat N, Varmani SG, Bansal T, McBain AJ, Marwah RG. A comprehensive review of microbial contamination in the indoor environment: sources, sampling, health risks, and mitigation strategies. Front Public Health 2023;11.
68. Najotra DK, Malhotra AS, Slathia P, Raina S, Dhar A. Microbiological Surveillance of Operation Theatres: Five Year Retrospective Analysis from a Tertiary Care Hospital in North India. Int J Appl Basic Med Res 2017;7(3):165-168.
69. Oulkheir A, Safouan H, El Housse F, Aghrouch M, Ounine K, Douira A, Chadli S. Assessment of microbiological indoor air quality in a public hospital in the city of Agadir, Morocco. Periodicum Biologorum 2021:123(1-2):29-34.
70. Poletti L, Pasquarella C, Pitzurra M, Savino A. Comparative efficiency of nitrocellulose membranes versus RODAC plates in microbial sampling on surfaces. J Hosp Infect 1999;41(3):195-201.
71. Yun H, Seo JH, Kim YK, Yang J. Examining the bacterial diversity including extracellular vesicles in air and soil: implications for human health. PLoS ONE 2025;20(4).
How to Cite
Issue
Section
License
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Transfer of Copyright and Permission to Reproduce Parts of Published Papers.
Authors retain the copyright for their published work. No formal permission will be required to reproduce parts (tables or illustrations) of published papers, provided the source is quoted appropriately and reproduction has no commercial intent. Reproductions with commercial intent will require written permission and payment of royalties.

