Then and now - changes in infection control procedures over the last decade


Are changes in infection control procedures in dentistry governed by fact or fiction? In this article I will be looking at key changes in infection control over the last decade and what led to them.

Were they due to actual events of cross-infection which necessitated new procedures and policies, or was it research into diseases that could possibly be transmitted in the dental surgery that led to them? Also, who influences these changes and how?

For many people, visiting the dental surgery creates feelings of fear and anxiety. These fears can stem from people’s own personal experiences, or from hearsay passed along from person to person. It seems that it is these fears and anxieties that can be easily increased with even the slightest mention in the media of any wrongdoing or misconduct in the dental industry. The public are often quick to believe negative stories, which can appear to validate and justify their fears and anxieties.

A famous case that caused much fear and panic occurred in 1990.  It was believed that a young US woman, Kimberly Bergalis, had contracted HIV from her dentist, Dr Acer, after he removed two of her molar teeth. This prompted the Florida Department of Health and Rehabilitative Services to test all of Dr Acer’s other patients. They found six more patients who could link their HIV infection to their dentist. However, the supposed cross-infection was never proven. As the LA Times reported in April 2001, '… to this day, no one can say just how Acer infected his patients with the deadly virus. It is a mystery that most AIDS experts acknowledge may never be solved' (Tanner, L., 2001). 

This story created a massive media buzz and worldwide panic that resulted in HIV sufferers being targeted out of fear and misunderstanding. To calm the situation, the American Dental Association recommended that all dentists should wear gloves (Mew, J., 2015). The UK GDC followed suit shortly after.

Even though this case of possible cross-infection was never proven, it highlights the power the media has to influence the public’s perceptions of dentistry. I believe that it is because of these perceptions that the governing bodies need to react. They do this by producing new manuals or implementing new procedures to reassure the public that they are being protected from certain threats - even if these threats are unproven. For example, the big change the above case brought about was the routine use of gloves by dentists in practice.

Research has played a massive part in moving dentistry forward, but it has also created many changes in cross-infection control. Research has found that variant Creutzfeldt-Jakob Disease can be transmitted via prion protein that can be found in the mouth (Ingrosso, L. et al., 1999). Much research has taken place which highlights the possible threat of such transmission, which in turn has led to studies that investigate the safest and most effective ways of eliminating this possibility through certain decontamination processes. 

However, these studies have proven unsuccessful, according to an article written by Christine Whitworth, which states that 'Decontamination techniques routinely used in general practice are incapable of inactivating the infected protein responsible for the transmission of the disease' (Whitworth, C., 2002). Furthermore, during a talk at the 6th Annual SWAG conference, Professor Collinge stated that: 'not only are prions not destroyed by sterilisation, but the protein specifically binds to metal, making it very difficult to remove even by good washing' (Collinge, 2003). 

A further study was published online in 2008. This explored the effectiveness of a washer disinfector at removing debris from endodontic files. The study originally aimed to 'compare the cleanliness of endodontic files that have be cleaned in a washer disinfector according to the file holder mechanism within the machine' (Assat, M. et al., 2008). However, it went on to prove that the files cannot be totally free from debris, and reinforced the view that such endodontic files should be single use only. The change from reuseable files to single use files was one of the changes that occurred in cross-infection control due to research in the last decade.

The study into the effectiveness of a washer disinfector removing debris from an endodontic file has left me questioning our overall ability to clean instruments to a satisfactory level. The HTM 01 05 highlights that using washer disinfectors in practices is seen as best practice - but there is very little research proving that this the most effective method of decontamination. Is it just an added step in the decontamination process that is there to reassure the public that everything is being done to decrease the risk of cross-infection (even if this step is more timely and expensive than is necessary?) 


Decontamination in dentistry will continue to change and progress. Changes can be initiated by a widely covered media story that prompts changes in order to counter negative public perceptions. Changes can also be a result of research that highlights a threat of a possible transmissible disease - this is combatted by adding precautionary steps to the decontamination process.

Overall, whether these changes come from the media or from vital research, it is clear that the dental industry will always aim to create decontamination processes that are proven to help protect patients from-cross infection. Even if processes have been created but have not yet been proven to be the most effective, it is reassuring to know that they seem to adopt an attitude of 'it's better to be safe than sorry'. It is because of this attitude that I, as a dental professional, feel safe in the knowledge that cross-infection control in dentistry will always evolve to provide the utmost protection for me and the general public in the future.


Author: Amba Williams, RDN, Level 3 Cert Dental Decon.




Assat, M., Mellor, A. & Qualtrough, A.J. (23rd May 2008) Cleaning endodontic files in a washer disinfector.  British Dental Journal Vol 204 (E17), DOI: 10.1038/sj.bdj.2008.411

Houghton, K. (2004) Journal of one day surgery proceedings of the 6th annual SWAG conference. Vol 14(2) 13-16 (online) available from

Ingrosso, L., Pisani, F. & Pocchiari, M. (1999) Transmission of the 263K scrapie strain by the dental route. J Gen Virol 1999 (80) 3043–3047

Mew, J., (24th April 2015) Glove wearing: an assessment of the evidence. British Dental Journal Vol (218) 451-452. DOI: 10.1038/sj.bdj.2025.292

Tanner, L. (2001) (online) available at

Whitworth, C. (1st July 2002) Variant Creutzfeldt-Jakobz Disease- A problem for General Dental Practitioners Vol 9(3) 95-99 (5) DOI: 10.1308/135576102322492945


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