Notable Research on Cross Contamination

1. J Can Dent Assoc. 2009 Feb;75(1):39. Dental burs and endodontic files: are routine sterilization procedures effective? Morrison A, Conrod S. Dalhousie University, Halifax, Nova Scotia. Republished in: Tex Dent J. 2010 Mar;127(3):295-300. [http://www.cda-adc.ca/JCDA/vol-75/issue-1/39.html]

Abstract

PURPOSE: The complex miniature architecture of dental burs and endodontic files makes precleaning and sterilization difficult. Devising a sterilization protocol for endodontic files and dental burs requires care, and some have suggested that these instruments be considered single-use devices. One purpose of this study was to determine the effectiveness of various sterilization techniques currently used in dentistry for the resterilization of dental burs and endodontic files. The second aim was to determine whether new dental burs and endodontic files, as supplied in packages from the manufacturer, are sterile.

MATERIALS AND METHODS: The sterility of new (unused) and used dental burs and endodontic files before and after various sterilization procedures was analyzed. New burs and files were tested immediately after removal from manufacturers' packaging, with or without prior sterilization. Burs and files that had been used in various dental offices were precleaned, packaged, resterilized and then tested for various pathogens. Each item was individually removed from the sterilization packaging, transferred by sterile technique into Todd-Hewitt broth, incubated at 37 degrees C for 72 hours and observed for bacterial growth.

RESULTS: Sterilization procedures were 100% effective for unused burs and unused files but were less than 100% effective for all other test groups. Contamination rates following sterilization ranged from 15% for one group of used burs (p = 0.01) to 58% for one group of used files (p < 0.001).

CONCLUSIONS: Dental burs and endodontic files, as packaged by the manufacturer, are not sterile and should therefore be sterilized before first use. The resterilization procedures tested here were not adequate, and more rigorous sterilization procedures are needed. If such procedures cannot be devised, these instruments should perhaps be considered single-use devices.

ADDITIONAL RESOURCES:

2. Contaminated dental instruments: Smith A, Dickson M, Aitken J, Bagg J.J Hosp Infect. 2002 Jul;51(3):233-5.
[http://www.rense.com/general34/evi.htm]

3. The antimicrobial efficacy of the erbium, chromium:yttrium-scandium-gallium-garnet laser with radial emitting tips on root canal dentin walls infected with Enterococcus faecalis: Wanda Gordon, DMD, Vahid A. Atabakhsh, DDS, Fernando Meza, DMD, Aaron Doms, DDS, Roni Nissan, DMD, Ioana Rizoiu, MS and Roy H. Stevens, DDS, MS JADA 2007; 138(7): 992-1002
[http://jada.ada.org/content/138/7/992.full]

4. A J Smith, Research Summary: Decontamination of dental burs, British Dental Journal 197, 623 (2004) Published online: 27 November 2004 doi:10.1038/sj.bdj.4811830
[http://www.nature.com/bdj/journal/v197/n10/full/4811830a.html]

5. C. L. Whitworth,1 M. V. Martin,2 M. Gallagher3 and H. V. Worthington, A comparison of decontamination methods used for dental burs, British Dental Journal Volume 197 No. 10 November 27 2004 [A comparison of decontamination methods used for dental burs, British Dental Journal]

6. Peter Bennett, Peter Grove, Luke Perera and Ian McLean, Potential vCJD Transmission Risks Via Dentistry: An Interim Review, Paper presented to the Spongiform Encephalopathy Advisory Group (SEAC), 14th December 2007

7. Bagg J, Sweeney CP, Roy KM, Sharp T, Smith A. Cross infection control measures and the treatment of patients at risk of Creutzfeldt Jakob disease in UK general dental practice. Br Dent J 2001; 191(2):87–90.
[http://eprints.gla.ac.uk/185/1/Bagg%5B1%5D.pdf]

8. Taylor DM. Inactivation of prions by physical and chemical means. J Hosp Infect 1999; 43 Suppl:S69–76.
[http://www.ncbi.nlm.nih.gov/pubmed/10658760]

9. Ingrosso L, Pisani F, Pocchiari M. Transmission of the 263K scrapie strain by the dental route. J Gen Virol 1999; 80(Pt 11):3043–7.
[http://www.ncbi.nlm.nih.gov/pubmed/10580068]

10. Adams DH, Edgar WM. Transmission of agent of Creutzfeldt-Jakob disease. Br Med J 1978; 1(6118): 987.
[http://www.ninds.nih.gov/disorders/cjd/detail_cjd.htm]

11. Ito M, Ashoori M, Osuka S, Matsuyama M, Usami T, Kaneda T, Dept. Oral Surgery, Nagoya University Sch. Medicine, Japan; International Conference on AIDS, Cross-contamination risks of invasive dental procedures using high-speed handpieces, Int Conf AIDS. 1994 Aug 7-12; 10: 185 (abstract no. PB0167).
[http://ww1.aegis.org/aidsline/1994/dec/M94C3773.html]