[MUSIC] In this module, which is newly added to this course, we're going to discuss the oral cavity's health prior to major medical or surgical procedures. Often the dentist will be asked to opine on a patient's oral health prior to heart valve surgery, prosthetic joint surgery, solid organ transplant, chemotherapy, radiation therapy, and antiresorptive medication therapy. Let's discuss each of these individually as they all have nuances that need to be taken into consideration. First, let's discuss the patient who is scheduled for a major heart surgical procedure, and that is a heart valve replacement surgery. As we understand, there is a potential risk of valve infection from dental-related bacteremia. That is bacteria from the oral cavity which travels through the bloodstream and potentially could infect a newly-placed heart valve. The dentist is often requested to eliminate potential sources of dental infection prior to this valve surgery. Many of us are familiar with the American Heart Association's guideline which was distributed in 2007 regarding the prevention of infective endocarditis. We'll not discuss this detail in this module, but this paper can serve as a significant background information for what we will discuss. In fact, bacteremia is associated even with tooth brushing, as well as dental extraction. As noted in the Lockhart article, although amoxicillin has a significant impact on bacteremia resulting from a single-tooth extraction. Turns out there's a greater frequency, obviously, for oral hygiene, including tooth brushing, and that may place a patient at a greater risk for infective endocarditis. If we look at this paper in greater detail, the incidence and duration of bacteremia associated with tooth brushing, associated with extraction, and associated with extraction while on an antibiotic all show that a bacteremic event will occur. Antibiotic prophylaxis will not necessarily eliminate all types of bacteremia. Another important paper by Lockhart suggests that poor oral hygiene is a significant risk factor of infective endocarditis-related bacteremia. Turns out oral hygiene and gingival in disease were associated with infectious endocarditis-related bacteremia after tooth brushing. Participants with a mean plaque and calculus scores of two or greater, were at a much higher increased risk of developing bacteremia. Turns out the presence of generalized bleeding after tooth brushing was associated with an almost eight-fold increase in the risk of developing a bacteremia from the oral cavity. So when a dentist is posed with the question of what to do prior to heart valve surgery, they're often thinking how can I eliminate, or at least significantly reduce the bacteremic event that occurs in patients during the perioperative period? Often it is impossible to completely eliminate the bacteremic event or events that occur throughout the day. However, if there is time available and if, in fact, the patient is medically stable to undergo dental procedures prior to the heart valve surgery, it makes some sense to decrease or, in fact, diminish anything with the possibility of causing a bacteremic event. Unfortunately, however, patients that are scheduled for heart valve surgery are often critically ill patients. In a more recent paper published in 2014, Smith et al., looked at the morbidity and mortality associated with dental extraction prior to a cardiac operation. Turns out patients with planned dental extraction before cardiac surgery were at risk for a major adverse outcome, including a 3% risk of death before the actual heart surgery, and an 8% risk of a major adverse outcome. So in their conclusion, the prevalence of major adverse outcomes should really advise physicians and dentists to evaluate the individualized risk of anesthesia and the individualized risk of the dental surgical procedure in this particular population. I think it's prudent to understand that acute dentoalveolar infection should be eliminated prior to heart valve surgery if, in fact, the patient can withstand that procedure. And oral hygiene should also be optimized prior to heart valve surgery if timing and the patient's medical stability permits. Another consideration for the dentist is pre-prosthetic joint replacement, or placement. Dentists are often questioned whether or not the patient has any active dental infection prior to a prosthetic joint being placed. Unfortunately, the question arises, is there truly a need for antibiotic prophylaxis? Well, there's very little scientific data to support the decision of prophylaxis. In fact, there is a lack of evidence that dental-induced bacteremia even cause prosthetic joint infections. In a recent publication from the Council on Scientific Affairs of the American Dental Association, the use of prophylactic antibiotics prior to dental procedures in patients with prosthetic joints was looked at. And in general, for patients with prosthetic joint implants, prophylactic antibiotics were not recommended prior to dental procedures to prevent prosthetic joint infection. Of course, each individual patient should be viewed in that context, that they are, in fact, individual patients. The clinical reasoning for this recommendation is that there is evidence that dental procedures are not associated with prosthetic joint implant infections. There is evidence that antibiotics prescribed before oral healthcare do not prevent prosthetic joint implant infections, and there are potential harms of using antibiotics. So the benefits of antibiotics may not exceed the harms for most patients. Once again, the individual patient's circumstances and preferences should be considered when deciding whether or not to prescribe an antibiotic prior to any dental procedure. So right now evidence fails to demonstrate an association between the dental procedure and the prosthetic joint implant. And evidence really fails to demonstrate any effectiveness for antibiotic prophylaxis. One must be mindful of the potential harm from antibiotic use, that is, using the antibiotics before the dental procedures. And additional case control studies are needed to increase the level of certainty in the evidence to a level higher than moderate. So when the dentist is faced with the question of eliminating dental infection prior to prosthetic joint placement, it is reasonable for the overall health of the patient to try and eliminate any ongoing infection. However, there needs to be further evidence looking at if this has any role in prosthetic joint failure or prosthetic joint infection.
