Canadian Hygienist Learns a Hard Lesson about Antibiotics and Joint Replacements

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Antibiotic prophylaxis prior to dental treatment and hygiene therapy was considered an issue, and guidelines were set in place by the American Heart Association in 2007 for patients potentially at risk for bacterial endocarditis. In 2012, both the American Dental Association (ADA) and the American Academy of Orthopedic Surgeons (AAOS) agreed that patients with prosthetic joint replacements were also at risk for dentally induced infection on the prosthesis.

However, as Dr. Eric Stoopler commented, “The 2012 guidelines were vague, and so a panel set out to review the previous literature and analyze newer studies to provide clear recommendations.”1 The ADA Council on Scientific Affairs responded to this directive in 2014 by creating a panel.

This 2014 panel judged with moderate certainty that there is no association between dental procedures and the occurrence of prosthetic joint infections.2 This judgment recommended, “In general, for patients with prosthetic joint implants, prophylactic antibiotics are not recommended prior to dental procedures to prevent prosthetic joint infection.”2

At this point, Canadian dental hygienists followed the Canadian Dental Association’s (CDA) recommendations for guidance to treating patients with knee replacements.2

The Canadian Orthopedic Association (COA), the Association of Medical Microbiology and Infectious Disease (AMMI), and the CDA reviewed the current best available evidence. They reviewed the effectiveness of dental antibiotic prophylaxis in the reduction of orthopedic prosthetic joint infections, within the context of the issue of emerging antimicrobial resistance and the critical role of all health-care providers to steward appropriate use of antimicrobial drugs.

These professional bodies conclude that:

  1. Most transient bacteremia of oral origin occurs outside of dental procedures.
  2. The significant majority of prosthetic joint infections are not due to organisms found in the mouth.
  3. Few prosthetic joint infections have an observable and clearly defined relationship with dental procedures.
  4. There is no reliable evidence that antibiotic prophylaxis prior to dental procedures prevents prosthetic joint infections.

Both Canadian and American dental associations followed the protocol set down by the 2014 panel.1-3 The American Dental Association and the Canadian Dental Association were in complete agreement and produced guidelines that recommended no antibiotic prophylaxis was necessary for two years post-placement of any prosthetic device. These documents were published as statements from each association in both the U.S. and Canada.2,3

Finding the Culprit in an Infection

Based on the above guidelines, my husband had his dental hygiene therapy carried out without antibiotic prophylaxis. It had been three years since his right knee replacement was modified due to a failure in the device. This follows the protocol for North America no matter whether in Canada or the US.

Exactly seven days later, he felt pain in his right knee while walking the dog. That night was painful as the knee started swelling, and he could not walk on it at all. A visit to the medical center resulted in a prescription for a possible infection in the knee as the radiographs of the knee were inconclusive.

After three days of no relief from the pain, swelling, and fever, I rushed him into the emergency department where the fluid was drained and a culture was taken. The next morning, he went into surgery where his prosthetic knee was removed and a temporary one inserted. This was in concert with intravenous (IV) antibiotics that were to be carried on daily for six weeks.

Four days after the culture was grown, the laboratory reported an overgrowth of streptococcus mutans.

Six weeks after the daily trips to the hospital for IV therapy, another culture will be taken, and, if clear, another knee replacement with resulting months of rehabilitation will be done.

This involves my husband being off from work for at least five to six months. The infection has caused us grief, severe pain, and has cost the Alberta Health Care system thousands of dollars.

We are now only two weeks past the emergency surgery. It is very demanding to look after my husband full time. Additionally, all the hospital caregivers are curious “to look under the dressing,” something the surgeon strictly prohibited. The treatment by hospital workers towards the primary caregiver is not always respectful.

Paying Closer Attention

Recommendations for clinical practice follow the evidence-based literature review of strong scientific studies. Although the literature found no evidence for the need for antibiotic prophylaxis, when it happens to that one in 100,000 patients, and he happens to be the husband of a hygienist, it is a big deal.

What evidence should we follow? Apply the guidelines to all patients except your loved ones? I think not.

It is imperative to carry out a full and updated medical history every year. However, when we are in the throes of treating baby boomers, we need to realize that they are on several medications and may also be immunocompromised.

Additionally, recent dental history experienced by patients at other dental offices should be collected. In this case, my husband had a tooth extracted two years ago and had an oro-antral communication that did not close until six months prior to the dental hygiene appointment. His white blood count is not normal when he is in good health.  It usually comes back low, less than 4,000 per microliter.

In the U.S., the updated 2014 clinical practice guideline is endorsed by the ADA alone. The 2012 guidelines were endorsed by both the ADA and AAOS. The AAOS did not give their stamp of approval on the 2014 guidelines.4 When this article was written, this small detail was noted. A return visit to Dr. Stoopler’s commentary showed further comments added by other dental specialists.1 One comment was from Dr. Michael Rethman who was on the panel for the guidelines. The comment implied the new recommendations failed to address the risk vs. benefit of utilizing antibiotics.

Dr. Rethman noted, “Instead it discusses solely the problematical issues associated with antibiotic use (eg., antibiotic-resistant strains, untoward patient reactions to antibiotics, etc.) with no accompanying discussion of the morbidity associated with the infections that such pre-medication seeks to prevent. In other words, there is a profound bias to the null in this paper. Plus, these latest authors extrapolated data on knees and hips to other anatomic areas which the initial panel refused to do. This is an assumptive jump that may very well be completely off-base. Pins in ankles are not hip replacements …”1

It may be seen as impertinent for a registered dental hygienist to cast aspersions on clinical practice guidelines governing prosthetic joint replacements and their relationship to the oral cavity. However, this dental hygienist will insist on obtaining a prescription from the dentist or orthopedic surgeon for antibiotic prophylaxis for all dental treatment for her husband from now on. In Alberta, Canada, dental hygienists may take additional education in prescribing antibiotics. This hygienist did not take the course and would have to rely on the dentist accepting the reasoning behind the request. To be sure, my husband will be taking antibiotic premedication before scaling or any dental procedures.

It seems important to have more studies on this issue as it applies to the aging population that we are now treating. We see many seniors in our practices in Alberta, and we should be aware of the number of placements of prosthetic hips and knees that present in our patients’ histories. It may be necessary to consult the orthopedic surgeon on the patient’s need for such coverage.

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  1. Commentary: The Use of Prophylactic Antibiotics Prior to Dental Procedures in Patients with Prosthetic Joints: Evidence-Based Clinical Practice Guideline for Dental Practitioners — A Report of the American Dental Association Council on Scientific Affairs. Retrieved from
  2. Sollecito, T.P., Abt, E., Lockhart, P.B., et al. J Am Dent Assoc.2015; 146: 11-16.
  3. Consensus Statement: Dental Patients with Total Joint Replacement. Canadian Dental Association. 2016. Retrieved from
  4. Management of Patients with Prosthetic Joints Undergoing Dental Procedures. American Dental Association. Retrieved from