Oral Health Group

Critique of the RCDSO Draft Document on: “Standard of Practice: Infection Prevention and Control in the Dental Office”

October 16, 2018
by John Hardie, BDS, MSc, PhD, FRCDC

Recently, the Royal College of Dental Surgeons of Ontario (RCDSO) welcomed comments on its draft document “Standard of Practice: Infection Prevention and Control in the Dental Office.” This critique is based on a thorough reading of the proposed Standard of Practice (referred to as the Standard) and its accompanying references. In addition, the author has utilized his knowledge of the subject as a foundation on which to critique this Standard. It is important to emphasize that as a retired member of the dental profession, the author has no vested interest in the Standard apart from ensuring that it fairly and honestly reflects the discipline of dental infection prevention and control. Accordingly, the critique will begin by illustrating the false premises on which the Standard is based.

False Premises
The Standard is justified by its proponents because:

  • It is evidence-based;
  • It combats increases in health care associated infections;
  • Dental patients are sources of infectious diseases;
  • Dental instruments and devices are considered critical items.

The false nature of these foundational principles will be discussed.

It would appear self- evident that a Dental Standard of Practice be based on evidence that is of a high level and readily available for inspection by its practitioners. Unfortunately, this Standard does not indicate what levels of evidence are used to justify its specific recommendations. There is a general and somewhat vague announcement that the recommendations are based on “well-designed scientific studies”, “strong theoretical rationale” or “suggestive evidence or opinions of respected authorities.” However, what or who these sources are does not appear in the Standard. Instead, dentists interested in assessing the strength of the justifying evidence need to analyse the various references attached to the Standard. This is a time consuming task but it does reveal interesting findings.

It is important to appreciate that the descriptor “Evidence- Based” allows for wide variation in both the strength and quality of the supporting evidence. For example, a recommendation might have a ranking of A1 implying that there is good supporting evidence based on, at least, one properly randomised, controlled trial. Another recommendation might have a ranking of B111 implying that there is moderate supporting evidence based on the opinions of respected authorities on the basis of clinical experience, descriptive studies or reports of expert committees. Both of these recommendations would qualify as being evidence-based. However, one is based on clinically derived evidence while the other simply reflects the opinions of a group which might have specific biases.

A major reference on which the Standard is based is the Ontario Ministry of Health 2013 document, “Best Practices for Cleaning, Disinfection and Sterilization of Medical Equipment/Devices in All Health Care Settings.” The document lists 86 recommendations, the overwhelming majority of which are not given evidence-based rankings but are supported by articles from the Canadian Standard Association. {The rationale used to arrive at the documents produced by this Association requires the purchase of the specific standard at a cost in excess of $100.00. The author was not prepared to make such purchases, and is unable to verify if the recommendations based on the Canadian Standards Association have any relevance to dentistry.} In this regard, it is worthwhile considering the views of Ward who believes that many infection control practices are, “governed by legislation which seems to have little convincing evidence to support them…”1

Surprisingly, only 11 of the recommendations in the Best Practices document are supported by an evidence-based ranking system. Of these only two are given a ranking of A1. Both are applicable to dentistry as they relate to the decontamination of new instruments prior to their use, and categorizing injection needles as single use items. The recommendation not to reprocess critical or semi-critical single use items has a ranking of A11, meaning that there has to be some supporting clinical evidence which might vary from a non-randomized clinical trial to the results from uncontrolled experiments. A similar ranking supports the evidence for a wall separating clean and decontamination areas. The recommendations associated with checking packaging, the results of chemical indicators and the reassembly of equipment have a ranking of A111 implying that the opinions of “experts” are relied on as there is no supportive clinical evidence. The recommendation that there should be a centralized area for reprocessing instruments is ranked as B111 indicating that “experts” are only moderately convinced of such a need. Compliance with this recommendation is an expensive undertaking, despite it having less than enthusiastic authoritative support. It is believed that dentists should be aware of the strength and quality of the evidence supporting Infection Prevention and Control Recommendations.

Another major reference attached to the Standard is the 2018 document produced by the Ministry of Health titled, “Best Practices for Environmental Cleaning for Prevention and Control of Infections in All Health Care Settings. Interestingly this article also has 86 recommendations. In it a strength grading of A implies that to ensure Best Practices the recommendation must be followed in all health care settings, while a grading of B means that to implement Best Practices the recommendation should be followed in most health care facilities. A quality grading of 111 implies that since there is no clinically derived evidence there is a reliance on the opinions of “respected authorities.” In this reference the overwhelming majority of the recommendations are either A111 or B111. In other words they are not relying on clinically based evidence.

It will be of interest to dentists to know that the recommendation which they are supposed to follow relating to the non-porous nature of surfaces, finishes and furnishings has a rating of A111 i.e. no supportive clinical evidence. The recommendation that gloves not be worn when walking between rooms has a similar ranking, as has the recommendation that there be routine environmental cleaning of health care settings. A designated area for storing clean linen is graded as B111 meaning that it is not necessary in all health care facilities and is simply an “authoritative” opinion.

The two major references noted above indicate that to qualify as part of Best Practices a recommendation should be introduced by the qualifier “must”. The Standard is replete with recommendations that “must” be enacted. The value of the Standard as an evidence-based document would have been enhanced if every “must” recommendation was assigned an evidence-based grading accompanied by a reference or references allowing the practitioner to easily assess the validity of the recommendation. Any document that purports to be evidence-based must be formatted in a manner which permits the reader to easily determine the strength and quality of the presenting evidence. The Standard proposed by the RCDSO fails to accomplish this objective. It provides no evidence-based rankings. The references it does list have minimal relevance to dentistry, and for the most part the evidence in the references relies on “authoritative” sources. Dentistry is a practical discipline. It would be hoped that recommendations regarding Standards of Practice are based on clinical findings and not on the opinions of anonymous experts.

Dentists are being asked to accept this Standard as a minimum requirement for clinical practice. Prior to so doing, they ought to appreciate that the evidence supporting it is difficult to find, and once found not all that relevant. This idea is supported by a 2001 article in the Canadian Journal of Infectious Diseases, which noted that, “Infection control interventions have yet to be validated in health care settings outside of acute care.” 2 The evidence-based nature of the Standard might be applicable to acute care facilities but has failed to account for the unique environment of ambulatory dental practice.

Increases in Health Care Associated Infections
The increases in Health Care Associated Infections are indicated as justification for the recommendations contained in the Standard. Accordingly, it is pertinent to assess these health care associate infections.

Health care associated or nosocomial infections are infections acquired by patients during a hospital stay or attendance at a health care facility. The most common types of such infections are:

  • Catheter associated urinary tract infections;
  • Central line associated bloodstream infections;
  • Ventilator associated infections;
  • Surgical site infections. 3

A variety of organisms are associated with these infections including Clostridium difficile, methicillin-resistant Staphylococcus aureus, and vancomycin resistant Enterococcus. 4

The first three forms of infections are associated with hospital procedures and are unlikely to be encountered in a general dental practice.

Unless the RCDSO is aware of properly conducted surveillance studies demonstrating a dramatic increase in oral surgery associated infections, there would appear to be no reason for justifying the Standard on the basis of nosocomial infections of dental origin.

Dental Patients Are Sources of Infectious Diseases
The Standard repeats the dogmatic assertion that, “all patients are potentially infective, even when asymptomatic.” This concept is used to justify that, “the same safe standards of practice must routinely apply to contact with blood, body fluids and secretions (e.g. saliva), mucous membranes and non-intact skin.” The word “potential” usually implies the capacity to develop into something in the future. Therefore, while it is true that at some later appointment the patient could be infectious, at any specific appointment the patient is either infectious or not infectious. Procedures pertaining to infection prevention and control should be based on the infectious state of the patient at the time of treatment not on the infectious nature of the patient at some future indeterminate date.

With this understanding, a risk assessment of the patient will identify the appropriate infection control procedures to adopt commensurate with the patient’s present health status and the planned treatment. This approach demands that dental personnel play an active dynamic role in adopting infection control techniques tailored for the patient and treatment rather than resorting to the habitual and often overused techniques advocated by “routine practices.”

Dental Instruments and Devices are Considered Critical Items
According to the Standard the mouth is, “a clean-contaminated environment.” It is not a sterile one. Saliva is non-sterile and blood appearing in the mouth is immediately contaminated by oral organisms. Invasions of oral tissues whether surgical or periodontal are automatically converted into contaminated fields. All dental instruments and devices operate in a non-sterile environment. With this understanding, it is necessary to consider the following statement from the Standard.

“For major dental procedures (similar to other surgical procedures), the patient is prepared, hand hygiene is performed, sterile gloves are worn, and all items that go into the sterile field are kept sterile, including instruments, materials and supplies that come in contact with the surgical site.” The RCDSO needs to explain how a clean-contaminated environment changes into a sterile field.

The document on Best Practices relating to Cleaning, Disinfection and Sterilization defines Critical Medical Equipment/Devices as ones that enter sterile tissues. It includes a dental hand pieces as an example of a critical item. This is obviously untrue as it is impossible for any instrument or device that operates in the mouth to enter non- contaminated sterile tissue. Therefore, such armamentaria should ideally be deemed non-critical. This is in keeping with the generally accepted attitude towards eating utensils. Forks, knives and spoons are exposed to an oral environment that contains saliva, possibly blood and a bountiful supply of organisms. Such cutlery is not considered by the general population nor public health authorities to require the full gamut of cleaning, disinfection and sterilization currently being recommended for dental instruments.

The Standard takes a slightly different approach than the Best Practices document as it describes Critical Items as ones that, “penetrate soft tissues or contact bone”. It does not mention sterile tissue which eliminates dental hand pieces and many other dental instruments and devices as critical items. The Standard justifies its definition because such critical items could be contaminated with any type of microorganism including bacterial spores. Bacterial spores are exceptionally rare in the oral cavity and the microorganism contaminating the items are more than likely those of the patients.

The Best Practices document and the Standard agree that critical items ought to be sterilized. The most appropriate criterion of a critical item according to Spaulding is if its operation will create a Portal of Entry. 5 The Standard fails to mention that a potential for infection does not exist unless a viable pathogen enters into tissue which for it will be “fertile soil.” The usual portals of entry are fresh breaks in the skin or on the mucous membranes lining the respiratory, gastrointestinal (including oral cavity) and urogenital systems. With this understanding, instruments such as scalpels, extraction forceps, surgical burs and retractors would qualify as critical items which require cleaning, disinfection and sterilization. Items such as mouth mirrors, probes, impression trays burs, saliva ejectors and hand pieces do not create Portals of Entry. Therefore they qualify as non-critical items which, being no different from eating utensils, do not require sterilization. The Standard recommends that all non-critical items be sterilized but provides no historical, microbiological or epidemiological evidence to support this claim.

There are only a few dental instruments whose intended purpose will create a Portal of Entry. They are deemed as critical and ought to be sterilized. The overwhelming majority of dental instruments are non-critical. There is no justification for treating those instruments any differently than household cutlery. Therefore, it should remain an informed decision of the practitioner whether or not to sterilize non-critical items.

Initial Conclusions
The RCDSO defines a Standard of Care as, “the degree of care that a reasonable and prudent dentist would exercise under the same or similar circumstances.” 6 It appears that this Standard has been based almost exclusively on Best Practice documents developed by the Ontario Ministry of Health for Acute Heath Care Facilities. It is supposed to be Evidence-Based. However, it is doubtful if a reasonable and prudent dentist would have the time to discover then read the few literature based references that are pertinent to dentistry. At least, such references would allow the dentist to assess the credibility of any clinically based evidence. For the most part, the dentist is denied this credibility check as anonymous panels of experts are frequently cited as sources of evidence. Dentists ought to know who these individuals are. (It has been suggested to the author that the inclusion of certain dental devices as semi-critical was based on dental ancillary personnel thinking it was “a good idea.”) This is not good enough for a Standard of Care.

There is no credible surveillance data to suggest that the practices of reasonable and prudent dentists are the sources of increases in Health Care Associated Infections. If the RCDSO believes differently it must provide the necessary evidence, while appreciating that surveys assessing compliance with existing or new protocols do not qualify as surveillance investigations. Reasonable and Prudent dentists would be expected to conduct health risk assessments on all patients prior to performing any aspect of a treatment plan. To insist that dentist adopt routine infection control procedures for all patients rather than rely on their ability to use ones commensurate with the risk assessment and proposed treatment, is to deny them professional integrity, knowledge and expertise.

Dentistry is a clinical discipline conducted in a non-sterile environment. By their very purpose a few dental instruments will create portals of entry leading to the inoculum of microorganisms. These are the only ones that need be cleaned, disinfected and sterilized.

Based on all of the above, it is believed that reasonable and prudent dentists would find it onerous, expensive and frustrating to follow a Standard that is not based on a thorough understanding of nosocomial infections of dental origin. Accordingly, what follows are a few examples of recommendations in the Standard which fail to recognise the nature of dental practice.

Personal Protective Equipment
The Standard’s reference to Routine Practices and Additional Precautions in All Health Care Settings has 60 recommendations. Only one has an A1 rating meaning that it is supported by clinical evidence. Not surprisingly, the recommendation relates to the value of hand hygiene. Dentists ought to know that the recommendation to wear a gown when splashes are anticipated is not supported by any clinically derived evidence. A recent article described why conventional face masks do not protect dental personnel from airborne pathogens. 7 Wilson, a prominent researcher noted in 2017 that non-sterile gloves are routinely misused by health care workers because they are being put on when not required, put on too early, removed too late and not changed at critical points in patient care. 8 Wilson believes that the over promotion of the routine use of personal protective equipment has removed from health care workers the need to use such equipment in an informed manner commensurate with the health status of the patient and attending staff, and the planned treatment. It should be appreciated that the Standard could promote the habitual over and misuse of personal protective equipment.

Prohibition of Eating and Drinking in Non-Designated Areas
The Standard is adamant that eating and drinking in operatories, instrument reprocessing areas and dental office laboratories is prohibited. Public Health Ontario gives this recommendation a ranking of A11 implying that while there is good supportive evidence it is not derived from ideal clinical investigations. Therefore, it might have been more appropriate to have recommended that in such locations eating and drinking are discouraged.

Cleaning, Disinfection and Sterilization of Patient-Care Items
The Standard indicates that, “residual organic debris will compromise the disinfection and sterilization process.” This is in contradiction to a 2012 article which states that, “In addition, there is little evidence in the published medical literature on whether failure to follow manufacturers’ recommended decontamination or servicing procedures leads to a residual infectious bioburden that poses a risk of transmission to subsequent patients.” 9

The Standard recommends a central reprocessing area for instruments and devices. As noted earlier, there is no clinically derived evidence supporting this demand. Dentists might wish to know the backgrounds of the “experts” making what might well be an expensive undertaking.

No evidence is provided to support the sterilization of cleaning brushes on a daily basis.

All dental instruments and devices are not used in a sterile field. Items removed from packaging are no longer sterile. Therefore, it behoves the RCDSO to provide the evidence justifying all of its recommendations relating to the preparation and packaging of dental instruments.

The Standard has numerous recommendations relating to sterilization. Sterilization is the absence of all viable organisms including viruses. In microbiology, the sterility assurance level (SAL) is the probability that a single unit that has been subjected to sterilization nevertheless remains viable. (10) It is never possible to prove that all organisms have been destroyed, as the likelihood of survival of an individual microorganism is never zero. SAL is an expression of the probability of survival. For example, most sterilizers are designed to have a SAL of 10 to the minus 6. This implies that there is a 1 in 1,000,000 chance of a non-sterile unit existing after sterilization. That is why Biological Indicators do not guarantee sterility. 11

The Standard correctly states that physical and chemical monitors do not ensure that, “sterility has been achieved.” However, biological indicators cannot give that assurance. Therefore, it is misleading for the Standard to imply that by using them there can be the assurance that all, “potential pathogens in the load have been killed.” There is a 1 in 1,000,000 chance that such a pathogen could have survived the sterilization process no matter how rigorously the process was documented and monitored. The sterilization processes recommended by the RCDSO do not ensure sterility.

Based on the above, if the RCDSO is unwilling to reconsider its entire approach to decontamination procedures, it must provide the clinical evidence to support its recommendations. It could begin by showing that failure to include a biological monitor in a package of instruments has resulted in the transmission of an infectious disease.

Clinical Contact Surfaces
An article in the American Journal of Infection Control states that, “Given the complex, multifactorial nature of nosocomial infections, well designed studies that systematically investigate the role of surface disinfection are required.” 12 There are no such studies in dentistry which justify the time consuming procedures recommended in the Standard with regards to environmental surfaces and those associated with dental radiography equipment.

Dental Handpieces and Similar Devices
The RCDSO must provide clinically substantiated proof justifying the requirement that handpieces and similar devices must be sterilized. If this cannot be produced, the RCDSO must identify the authority used to warrant the recommendation.

Additional Comments
Following requests to provide the author with articles supporting its recommendations regarding infection prevention and control in dentistry, the Ontario Ministry of Health referenced the 2016 article, “Transmission of blood-borne pathogens in US dental care settings.” 13 It is interesting to note that the 12-year span of the review article failed to find a single case of HIV transmission possibly linked to dental treatment. The single case of possible HCV transmission occurred in an oral surgery practice. Although there were numerous infection control infractions in the office including the reuse of single dose medication vials, the investigators were unable to determine the route of transmission. There was a single case of possible HBV transmission in an oral surgery office which was speculated as having occurred from environmental surfaces. Five cases of acute HBV infection were reported as having occurred in a 2-day portable dental clinic. Although there were reportedly breeches in normal infection control procedures at the portable clinic, it was not possible to link any specific practices to the transmission of HBV.

It is worthwhile noting that the document used by the Ministry of Health to justify its dental infection control recommendations is based not on a clinically confirmed route of transmission but on pure speculation.

The paucity of blood-borne transmissions during the 12-year period is supported by the author’s findings regarding the surprising absence of disease transmission from infection control disasters. 14

The Ministry of Health appears to have an unjustified concern that HIV, HBV and HCV are transmitted during dental care. Appendix 1 of the Standard notes that low level disinfectants kill enveloped viruses such as HIV, HBV and HCV. In a recent major paper Holodniy and colleagues state that, “Current reprocessing guidelines have documented that HBV, HCV and HIV are readily inactivated by commonly used cleansing mechanisms.” 9 The Ministry of Health needs to explain how these viruses survive routine cleaning, disinfection and sterilization no matter to what degree the sterilization cycle is monitored.

Final Conclusions
The Standard is supposed to represent the infection prevention and control practices of reasonable and prudent dentists. Dentistry is performed in a non-sterile environment and, for the most part, on relatively healthy ambulatory patients in private practice offices. The Standard has failed to recognize this by insisting that dentists adopt standards of care more attuned to acute health care facilities. The significance of this failure was understood by Lee who in 1997, after conducting surveillance studies of acute and non-acute care settings, concluded that, “For some settings, such as most ambulatory care and behavioral health settings, the theoretic risks of the most common nosocomial infections found in acute care settings are almost non-existent.” 15

In 1981, Dr. J. D. Millar (an early proponent of infection control) was adamant that, “We must be extremely careful in public health to minimize the actions we take based on no or few facts.” 16 Some years later Dr. R. A. Weinstein reiterated this fundamental principle by stating that, “…health care epidemiologists must ensure that the fervour for new interventions is met with sufficient supporting evidence.” 17 This critique is replete with examples of where the Standard has failed to provide such evidence that is pertinent to dentistry.

A notable absence in the Standard is any reference to costs. Implementing all of the Standard’s recommendations will necessitate immediate and long term capital and labour expenses. There is no evidence that the RCDSO conducted a cost benefit analysis of what infectious disease transmissions will be prevented or reduced if its recommendations on infection control are implemented. Such an undertaking is not only important to private practitioners who will finance such costs, it is a fundamental tenet of infection prevention and control, recognized by Dr. T. C. Eickhoff (a founding father of modern infection control) who said, “…we rarely determine that the recommendations we make, in fact, do what we want them to do within a cost-effectiveness figure that we can accept.” 18

It is concluded that the Standard is inadequate because it assumes that dental care promotes infectious conditions, it provides little in the way of supporting clinically derived evidence, and it fails to include a cost benefit analysis of its recommendations. OH

Oral Health welcomes this original article.


  1. Ward D. Implementing evidence-based practice in infection control. British J Nursing, 2000; 9(5): 267-271
  2. Nicolle L. Infection control in acute care facilities: Evidence-based safety. Can J Infect Dis 2001; May-June; 12(3): 131-132.
  3. Healthcare associated infections (HAIs). Available at: http://www.premiersafetyinstitute.org/safety-topics-az/healthcare-associated-infections-hais/hai/
  4. About Healthcare-associated infections. Available at: https://www.picnet.ca/surveillance/about-hai/
  5. Spaulding E.H. Chemical Disinfection of Medical and Surgical Instruments. In; Lawrence C.A. Block S.S. eds. Disinfection, sterilization and preservation. Lea and Febigar, Philadelphia 1968; 517-531.
  6. The standards of practice in dentistry: what does that mean? RCDSO Dispatch 2017 issue 2.
  7. Hardie J. Why Face Masks Don’t Work: A Revealing Review of Their Inadequacies. Oral Health, Oct 2016; 64-71.
  8. Wilson J. Applying human factors and ergonomics to the misuse of nonsterile clinical gloves in acute care. Am J Infect Control 2017; 45(7): 779-786.
  9. Holodniy M. Results from a Large-Scale Epidemiologic Look-back Investigation of Improperly Reprocessed Endoscopy Equipment. Infect Control and Hospital Epidemiology 2012; 33(7): 649-656.
  10. Sterility Assurance Level Available at: https://en.wikipedia.org/wiki/sterility_assurance-level.
  11. 3 M Attest Biological Indicators. Policy: Evidence of an effective steam sterilization process will be documented.
  12. Dettenkofer M. Does disinfection of environmental surfaces influence nosocomial infection rates? A systematic review. Am J Infection Control 2004; 32(2): 84-89.
  13. Cleveland J.L. Transmission of blood-borne pathogens in US dental health care settings 2016 Update. J Am Dent Assoc 2016; 147(9): 729-738.
  14. Hardie J. The Surprising Absence of Disease Transmission From Infection Control Disasters. Oral Health Sept 2015: 14-18
  15. Lee T. B. Surveillance in Acute Care and Non Acute Care Settings: Current Issues and Concepts. Am J Infection Control, 1997; 25(2):121-124.
  16. Millar J.D. Commentary. American Journal of Medicine. 1981; 70:983-985.
  17. Weinstein R.A.Who is Steering the Ship? External Influences on Infection Control Programs. Clin Infect Dis 2008; 46(11):1746-1750.
  18. Eickhoff T.C. Commentary. American Journal of Medicine. 1981; 70:980

About the Author
Although retired from practice, Dr. Hardie maintains a thirty plus years interest in the discipline of infection control as it relates to dentistry. He has published extensively on the subject and has lectured on it and related subjects throughout North America, the UK, Europe, and the Middle and Far East.