Antibiotic Prophylaxis: When and Why

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Introduction
Infective endocarditis (IE), also referred to as bacterial endocarditis (BE), is an infection caused by certain bacteria that enter the bloodstream and settle in the heart lining, a heart valve or a blood vessel. Infective endocarditis is uncommon, but people with some heart conditions have a higher risk of developing it (AHA, 2018).
Total joint replacement, or arthroplasty, represents a significant advance in the treatment of disabling joint pathologies. Surgical replacement can be performed on any joint of the body, including hips, knees, ankles, shoulders, elbows, wrists, and fingers. The vast majority of joint replacements involve the knee and the hip. Surgical replacement of total hip and knee joint arthroplasty is expected to increase due to an aging population, the most common reason for replacement being disabling effects of arthritis (both osteoarthritis and rheumatoid arthritis (Horder, 1909;Thayer, 1926). Although the worldwide prevalence of total joint replacements is unclear, what is clear is that hip and knee replacement is a standard procedure in the orthopedic practice of medicine. Prosthetic joint infections are the most common reason for prosthetic joint failure.
Prosthetic joint infections are not common, but serious complications do occur in a tiny percentage (0.3 to 1.0%) of patients after primary total hip replacement and (1.0 to 2.0%) of patients after primary total knee replacements. The most significant risk occurs during the first two postoperative years (6.5, 3.2, and 1.4 infections per 1000 patient-years during the first year, second year, and after the second year, respectively). 3 Staphylococci (S. aureus) are the most common bacterial cause of prosthetic joint infections. This microorganism is uncommon in the oral cavity. 3 Devastating personal and financial consequences can arise following such an infection. Treatment often requires removal of the infected prosthesis and prolonged intravenous antimicrobial therapy, along with an estimated cost that may exceed $50,000.00 for each episode. 4 This was the primary reason that orthopedists supported the use of antibiotic prophylaxis before the dental procedures, believing it might prevent the infection.

Antibiotic Prophylaxis: Prosthetic Joints and Orthopedic Implants
The American Dental Association has found it is no longer necessary for most dental patients with orthopedic implants to have antibiotic prophylaxis to prevent infection.

From the American Dental Association:
Antibiotic prophylaxis (or premedication) is merely the taking of antibiotics before some dental procedures such as teeth cleaning, tooth extractions, root canals, and deep cleaning between the tooth root and gums to prevent infection. We all have bacteria in our mouths, and a number of dental treatments-and even daily routines like chewing, brushing or flossing-can allow bacteria to enter the bloodstream (bacteremia). For most of us, this isn't a problem. A healthy immune system will prevent these bacteria from causing any harm. There is a concern, however, that bacteria in the bloodstream could cause infection elsewhere in the body.
Prior to 2012, premedication prior to dental procedures was common for joint replacement patients, even though there was little evidence to support the practice and experts recommended against its practice for most dental patients. In 2012, the American Dental Association and American Association of Orthopedic Surgeons published updated guidelines, stating that dentists "might consider discontinuing the practice of routinely prescribing prophylactic antibiotics." In January 2015, the American Dental Association's Council on Scientific Affairs issued another guideline, which continued to discourage prophylactic antibiotic use for most patients with prosthetic joint implants. Guidelines are re-evaluated every few years to make sure that they are based on the best scientific evidence.
Based on careful review of the scientific literature, the American Dental Association found that most dental treatments are not associated with prosthetic joint implant infections and that antibiotics given before dental procedures do not prevent such infections.
In fact, for most people, the known risks of taking antibiotics may outweigh the uncertain benefits. Known risks related to antibiotic use include nausea, gastric upset and the potential for allergic reactions, including anaphylactic shock. Other risks include developing antibiotic resistance to bacteria, which can complicate treatment of infections such as strep throat, pink eye, and meningitis; as well as increasing the risk of C. difficile infection, which causes diarrhea and intestinal problems. Patients over 70 years old are also at an increased risk of exhibiting symptoms of adverse reactions to some antibiotics.
Additionally, the American Academy of Orthopedic Surgeons is unable to recommend for or against the use of topical, oral antimicrobials in patients with prosthetic joint implants or other orthopedic implants undergoing dental procedures. Based on research the AAOS has made the following statements concerning recommendations when the research is inconclusive, consensus: Practitioners/ clinicians should feel little constraint in deciding whether to follow a recommendation labeled as inconclusive and should exercise judgment and be attuned to any future publications that clarify existing evidence for determining the balance of benefits versus potential harm. It has been determined that patient preference should have a substantial influencing role.
In the absence of reliable evidence linking poor oral health to prosthetic joint infection, it is the opinion of the AAOS work group that patients with prosthetic joint implants or other orthopedic implants maintain appropriate oral hygiene. The supporting evidence is lacking and requires the workgroup to make a recommendation based on an expert opinion by considering the known potential harm and benefits associated with the treatment. A Consensus recommendation means that expert opinion supports the guideline recommendation even though there is no available empirical evidence that meets the inclusion criteria.
Implications: Practitioners should be flexible in deciding whether to follow a recommendation classified as Consensus, although they may set boundaries on alternatives. Patient preference should have a substantial influencing role.
For example, one may read a recent study or paper on antibiotic prophylaxis. Here are some guidelines to consider when determining if a protocol should be changed.
Description: Evidence from two or more "Low" strength studies with consistent findings, or evidence from a single Moderate quality study recommending for or against the intervention or diagnostic. A Limited recommendation means the quality of the supporting evidence that exists is unconvincing, or that well-conducted studies show little clear advantage to one approach versus another. Implications: Practitioners should be cautious in deciding whether to follow a recommendation classified as Limited and should exercise judgment and be alert to emerging publications that report evidence. Patient preference should have a substantial influencing role.

Antibiotic Prophylaxis for Heart Patients
The American Dental Association in conjunction with the American Heart Association (AHA) released guidelines for the prevention of infective endocarditis in 2007 (Wilson et al.), which were approved by the CSA group (Codes and Standards) as they relate to dentistry in 2008 (Wilson et al.). In 2017, the AHA and American College of Cardiology (ACC) published a focused update to their 2014 guidelines on the management of valvular heart disease that reinforce the previous recommendations (Nishimura et al., 2017).
Current guidelines endorse infective endocarditis premedication for a small subset of patients. A review of scientific evidence, which showed that the risk or premedication outweighs the benefits of prophylaxis for many patients that would have been eligible for prophylaxis in earlier versions of the guidelines. The possible development of drug-resistant bacteria was a significant factor.
The available data has been varied as to whether antibiotics taken before a dental procedure will actually prevent infective endocarditis. The guidelines state that individuals at risk for infective endocarditis are habitually exposed to oral bacteria while attending to necessary daily activities such as brushing or flossing. The disease management guidelines recommend that persons at high risk of developing bacterial infective endocarditis should establish and maintain the best possible oral health to reduce potential sources of bacterial seeding (Nishimura et al., 2017).

Patient Selection
The current infective endocarditis/valvular heart disease guidelines state that the use of preventive antibiotics before specific dental procedures is reasonable for patients with: • prosthetic cardiac valves, including transcatheter-implanted prostheses and homograft • prosthetic material used for cardiac valve repairs, such as annuloplasty rings and chords • history of infective endocarditis; • a cardiac transplant a with valve regurgitation due to a structurally abnormal valve; • following congenital (present from birth) heart disease: b • unrepaired cyanotic congenital heart disease, including palliative shunts and conduits • any repaired congenital heart defect with residual shunts or valvular regurgitation at the site of or adjacent to the site of a prosthetic patch or a prosthetic device a According to limited data, infective endocarditis appears to be more common in heart transplant recipients than in the general population; the risk of infective endocarditis is highest in the first six months after transplant because of endothelial disruption, high-intensity immunosuppressive therapy, frequent central venous catheter access, and frequent endomyocardial biopsies. b Except for the conditions listed above, antibiotic prophylaxis is no longer recommended for any other form of congenital heart disease.

Pediatric Patients
Congenital heart disease can indicate that prescription prophylactic antibiotics may be appropriate for children. When antibiotic prophylaxis is called for due to congenital heart concerns, they should only be considered when the patient has: • Cyanotic congenital heart disease (congenital disabilities with oxygen levels lower than average) that has not been repaired (children with surgical shunts and conduits may be included in this group) • A congenital heart defect that's been completely repaired with prosthetic material (up to six months after the repair) • Repaired congenital heart disease with remaining defects, such as leakage near to a prosthetic patch or device.
Antibiotic prophylaxis is not recommended for any other form of congenital heart disease.
Beyond identifying the specific patient population for whom antibiotic prophylaxis is appropriate, special consideration should be given to the antibiotic dose prescribed to children, as it will vary according to the child's weight. Weight-based regimens for children are outlined in Table 2 of the 2007 American Heart Association guidelines. As with any medication, check with the primary caregiver to determine whether the child has an allergy to antibiotics or other antibiotic related concerns before prescribing.

Dental Procedures
Prophylaxis is recommended for the patients identified in the previous section for all dental procedures that involve manipulation of gingival tissue or the periapical region of the teeth, or perforation of the oral mucosa.

Additional Considerations About Infective Endocarditis Antibiotic Prophylaxis (When Indicated)
Sometimes, patients may forget to premedicate before their appointments. The recommendation is that for patients with an indication for antibiotic prophylaxis, the antibiotic is given before the procedure. This is important because it allows the antibiotic to reach adequate blood levels.
However, the guidelines to prevent infective endocarditis, state, "If the dosage of antibiotic is inadvertently not administered before the procedure, the dosage may be administered up to 2 hours after the procedure." If a patient with an indication for prophylaxis who appropriately received antibiotic premedication prior to a dental procedure one day and who is then scheduled the following day for a dental procedure also warranting premedication (e.g., dental prophylaxis), the antibiotic prophylaxis regimen should be repeated prior to the second appointment. Because of the nature of the pharmacokinetics of an antibiotic prophylaxis regimen, a single loading dose is given in order to cover the period of potential bacteremia produced by a single procedure .
Another concern that dentists have expressed involves patients who require prophylaxis but are already taking antibiotics for another condition. In these cases, the guidelines for infective endocarditis recommend that the dentist select an antibiotic from a different class than the one the patient is already taking (Mylonakis & Calderwood, 2001). For example, if the patient is taking amoxicillin, the dentist should select clindamycin, azithromycin or clarithromycin for prophylaxis.
In 2015, The Lancet published a study out of the United Kingdom that reported a correlation between the institution of more limited antibiotic prophylaxis guidelines by the National Institute for Health and Clinical Evidence (NICE) in 2008 and an increase in cases of infective endocarditis. 13 Because of the retrospective and observational nature of the study, the authors acknowledged that their "data do not establish a causal association." At this time, the ADA recommends that dentists continue to use the AHA/ACC guidelines discussed above. Dental professionals should periodically visit the ADA website for updates on this issue.

Whom Can Antibiotic Prophylaxis Help?
Depending on the patient's personal medical history, one may still be a candidate for premedication. For example, antibiotic prophylaxis might be useful for patients undergoing dental procedures that also have compromised immune systems (due to, for instance, diabetes, rheumatoid arthritis, cancer, chemotherapy, and chronic steroid use), which increases the risk of orthopedic implant infection. It may also benefit others with heart conditions. Patients should talk with their dentist and physician about whether antibiotic prophylaxis before dental treatment is necessary.
The possibility that bacteremia from the mouth could cause infective endocarditis was first suggested more than 100 years ago, and it was later reinforced by others who targeted the viridans group streptococci usually from poor oral hygiene and dental extractions. These observations, along with the advent of antibiotics, eventually led to the first guidelines from the American Heart Association regarding antibiotics as a preventive measure in dentistry in 1955.
Antibiotic prophylaxis (AP) became the primary focus for prevention of infective endocarditis and a standard of care for countries around the world. Controversy concerning efficacy and safety issues has existed for more than 30 years, and there has been a steady reduction in the patient populations and the procedures suggested for antibiotic prophylaxis since that time. Of concern, and despite decreasing emphasis on antibiotic prophylaxis for cardiac patients, upwards of 25 noncardiac patient populations are recommended for pretreatment antibiotics by some clinicians out of concern for systemic infections that might originate from dental procedures (e.g., prosthetic joints) .
Because there are significant differences in recommendations from experts in the United States, the United Kingdom, and other countries one can surmise a lack of convincing data to either enforce or dispute this practice. The National Institute for Health and Clinical Excellence (NICE) in the United Kingdom issued new recommendations in 2006, which took the bold step of eliminating antibiotic prophylaxis altogether (Lockhart &Brennan,2008). Current American HA guidelines narrow the focus to only a few cardiac groups at higher risk for a bad outcome from IE but who represent ≈10% of all people at risk for infective endocarditis. . The AHA-defined moderate-risk groups represent ≈90% of people at risk for infective endocarditis, all of whom were recommended for antibiotic prophylaxis before 2007. There are, therefore, no preventive guidelines for the millions of people in the United States at risk for contracting infective endocarditis but who are not felt to benefit from AP (Mylonakis & Calderwood, 2001).
Although there is an understandable concern on the part of some cardiologists and some patients about eliminating AP, a recent retrospective study by Thornhill et al. (2011) suggests that AP has no significant impact on the incidence of, or death from, IE. The authors point out that these findings may not apply to patients in the higher risk groups because ≈20% of physicians in the United Kingdom may continue to use antibiotic prophylaxis despite NICE guidelines that mandate a cessation for this practice unless the patient requests it. This group did find a modest increase in the incidence of IE over their 10-year period as a result of both streptococci and staphylococci. Support for the role of oral bacteria as a significant cause of infective endocarditis comes mostly from 2 sources. The best evidence for this association is the frequency with which specifically oral bacterial species are cultured from the blood of patients with community-associated infective endocarditis (CA-IE). The literature suggests that 20% to 65% of cases of infective endocarditis worldwide result from bacteria that can be found in or are exclusive to, the mouth Mylokanis, & Calderwood, 2001;Tleyeh, I.M et al.,2005). This wide range of cases of infective endocarditis attributed to oral bacteria stems, in part, from the use of standard biochemical rather than molecular methods of bacterial identification . For example, reports of viridans group streptococcus are not specific enough to implicate the mouth as the source. Other supporting documentation comes from >75 years of bacteremia studies of dental procedures and other manipulations of gingival tissues (Okell & Elliott, 1935). These studies suggest a wide range of incidence of bacteremia from species known to cause Infective Endocarditis, and one must conclude that oral bacteremia is likely to occur with the majority of dental office visits. These studies use surrogate measures of risk for IE (i.e., incidence, duration, nature, and magnitude of bacteremia), but they have driven the focus on antibiotic prophylaxis for dental procedures since the 1950s.
Retrospective case-control studies provide a closer look at this relationship. Strom et al. (1998) contacted patients who had been hospitalized (cases) for infective endocarditis at 1 of 54 hospitals in the Philadelphia area and compared them with matched community residents (controls). His group found that recent dental treatment was no more frequent in cases than in controls, and they concluded that dental treatment did not seem to be a risk factor for CA-IE. The study by DeSimone et al. (2012) in Circulation moves the clinician to a better understanding of the efficacy for AP by conducting the first population-based study in the United States to determine the impact of the 2007 American Heart Association guidelines. The group focused on cases of infective endocarditis from presumed oral streptococci over a 12-year period and found no increase in viridans group streptococcus infective endocarditis in the 2+ years since 2007. Of interest, 2 of the three patients who developed infective endocarditis from viridans group streptococcus after 2007 had not been to the dentist in the previous six months, and the third patient had antibiotic prophylaxis before a recent dental office procedure.
Case-control, population-based, and other epidemiological investigations often have methodological weaknesses that soften their impact: (1) small sample size and power; (2) subject recall bias; (3) demographics that may not be representative of the general population; (4) incubation time frames that are too long for infective endocarditis; (5) the imperfect nature of hospital and national databases on admission and discharge coding and nonspecific ICD-9 coding of bacterial species. Nevertheless, results from well-designed studies are essential because they provide additional evidence that the well-intentioned focus on antibiotic prophylaxis may be misdirected.
The AHA, Institute of Medicine, NICE, and other professional groups have called for studies that would resolve this longstanding question concerning the efficacy of antibiotic prophylaxis and clarify the role of poor oral hygiene and resulting periodontal disease in the pathogenesis of infective endocarditis (NICE, 2008;Wilson et al., 2007;Institute of Medicine, 2000). A prospective, randomized, double-blind study of antibiotic prophylaxis in people at risk for CA-IE, however, has significant obstacles: (1) there are ethical and legal concerns about randomizing people in the AHA higher risk group to a placebo (2) such a trial would only address the 10% of people currently recommended for antibiotic prophylaxis in the United States (3) given the rarity of infective endocarditis, it has been estimated that upwards of 30 000 people at risk would be needed to detect a clinically significant antibiotic prophylaxis treatment effect, and the cost of this trial would be prohibitive.
Transient bacteremia frequently occurs as a result of dental plaque accumulation, evolving to a dense mat of oral bacteria around the teeth which cross the inflamed periodontal pocket tissues to the circulation. Clearly, this must be the primary source and portal of entry for the oral bacterial species that cause upwards of 25% of cases of CA-IE. Current science strongly suggests that poor oral hygiene and periodontal disease are far more significant risk factors for the development of oral bacteria-related IE than invasive dental procedures. The most extensive study to date compared to tooth extraction, a highly invasive dental procedure, with tooth brushing as a standard, naturally-occurring source of bacteremia . This group found that the incidence of bacteremia from tooth brushing (32%) was high enough to strongly suggest that bacteremia from various activities of daily living (chewing food as well) may occur hundreds of times more often than bacteremia from dental office procedures.
It has been suggested that some individuals may generate bacteremia for 90 hours each month from such physiological causes, by comparison with dental office procedure-generated bacteremia of 1 to 2 times per year on average (Guntheroth, 1984). This study provides unique documentation of a strong association between 3 oral hygiene and gingival disease measures and the incidence of bacteremia with Infective Endocarditis-related species (Lockhart, 2009). These associations strengthened with higher levels of dental plaque and calculus and gingival disease.
DeSimone and colleagues have provided further data to reinforce the trend toward a significantly decreased number of cardiac patients recommended for AP, as well as support for a more definitive study to determine the extent to which oral hygiene, periodontal disease, and oral bacteria are associated with CA-Infective Endocarditis. These data would improve our understanding of risk factors and refocus efforts on prevention of Infective Endocarditis to improving oral hygiene and preventing periodontal disease. This information has the potential to reduce the overall incidence of CA-Infective Endocarditis, it would be immediately transferable to everyday clinical practice, and it would inform future AHA and other international guidelines on preventive strategies for Infective Endocarditis.

Adverse Effects of Antibiotic Prophylaxis
Prior to 1997, any patient with a history of total joint replacement (TJR) was advised to receive AP prior to oral procedures. During this time concern increased regarding the development of antibiotic resistance and the connection to the unnecessary use of antibiotics. Antibiotic prophylaxis was suggested as a practice promoting antibiotic resistance. This adverse effect led the professional associations' expert committees to identify appropriate uses for AP in the patient with TJR. The 2003 ADA/AAOS guidelines determined that only selected individuals with TJR would likely benefit from AP, and only when specified oral procedures involved significant bleeding. It was thought at that time that procedures resulting in bleeding were likely to result in bacteremia. Later research revealed bacteremia resulted in practices unrelated to bleeding, such as chewing or restorative dental treatment (AOS, 2009).
Other adverse factors associated with AP include nausea, the risk for antibiotic-associated colitis (C. difficile), candidiasis, drug interactions, and cost.

Efficacy for Antibiotic Prophylaxis to Prevent Prosthetic Joint Infection
Guidelines for the efficacy of antibiotic prophylaxis (AP) prior to oral procedures for individuals with a joint replacement have gone through several revisions. Guidelines have changed from using AP before dental procedures for all individuals with a prosthetic joint to using AP for only selected patients considered to be at high risk for joint infection, then to no recommendation for AP prior to dental procedures. In December 2012 the American Academy of Orthopedic Surgeons (AAOS) in collaboration with the American Dental Association (ADA) published three clinical practice guidelines based on a systematic review (SR) of best evidence related to factors that might cause joint infection and risk factors for prosthetic joint infection (PJI), followed by an explanation of the guidelines for practitioners in 2013. These included (1) The practitioner might consider discontinuing the practice of routinely prescribing prophylactic antibiotics for patients with hip and knee prosthetic joint implants undergoing dental procedures. (2) We are unable to recommend for or against the use of topical, oral antimicrobials in patients with prosthetic joint implants or other orthopedic implants undergoing dental procedures.
(3) In the absence of reliable evidence linking poor oral health to prosthetic joint infection, it is the opinion of the work group that patients with prosthetic joint implants or other orthopedic implants maintain appropriate oral hygiene.
A central goal of the review was to examine the evidence directed towards efficacy (do they work, and if so, how well?) of AP to prevent PJI. The 2012 AAOS/ADA guideline #1 called for practitioners to "consider discontinuing the use of AP before dental procedures when the client has a knee or hip prosthetic joint." The guideline statement was followed, however, by an explanation that the recommendation was based on only one prospective case-control study 5 , considered to be "limited evidence." The guideline authors wrote that practitioners should not feel compelled to follow a guideline based on "limited evidence." This negative statement was confusing to many. Multiple groups involved in the scientific investigation agreed there was an absence of level 1 evidence (randomized controlled trials) for or against the use of prophylactic antibiotics in patients with prosthetic joints undergoing invasive dental treatment. The 2012 ADA/AAOS guidelines were published, but they did little to guide practitioners regarding evidence-based professional decisions for dental management of the client with a joint replacement. Most authorities in dentistry agree professional judgment must depend on the client history of infection in the joint space following joint replacement, and the strength of the host immune response to resolve the infection (Jevsevar & Abt, 2013).
In January of 2015, the ADA Council of Scientific Affairs Expert Panel on Antibiotic Prophylaxis attempted to determine if AP was needed for individuals having a prosthetic joint, seeking dental treatment. In the Clinical Guidelines publication, the Expert Panel used four studies which were deemed to answer the focused question "Does antibiotic prophylaxis prevent prosthetic joint infection?" The Expert Panel determined "In general, for patients with prosthetic joint implants, prophylactic antibiotics are not recommended prior to dental procedures to prevent prosthetic joint infection" (Sollecito, Abt, et al. 2015). For patients who have had previous complications (such as previous joint infection, or are immunocompromised) and who will have gingival manipulation (scaling/periodontal debridement) or mucosal incision, consultation with the physician is advised before making final decisions regarding whether or not to use antibiotic prophylaxis.
In 2009, without collaboration with the ADA, a committee of the AAOS published a new statement calling for antibiotic prophylaxis prior to oral procedures in all individuals with a TJR. This caused worldwide confusion since an examination of worldwide professional guidelines for AP at that time revealed many professional organizations in the United Kingdom (UK), Japan and European countries did not recommend AP prior to dental procedures to prevent PJIs.
One factor associated with a lower risk of PJI was good oral hygiene or oral health. This study was considered in the 2012 ADA/AAOS third recommendation.

Role of Oral Health
Randomized studies have demonstrated that bacteremia after tooth brushing is associated with poor oral hygiene and gingival bleeding. The tooth brushing study reported an almost eightfold increase in the risk for bacteremia in the group with generalized bleeding. An analysis of data from this study reported the incidence of bacteremia in the group with high plaque and calculus scores was not significantly different from the group having a single tooth extraction. Results, such as this, support the recommendation for individuals with prosthetic joints to maintain oral cleanliness and healthy oral tissues. The recommendation for individuals to maintain healthy periodontal tissues and reduce apical or other oral infection comes from the logic that healthy tissues would lower the magnitude of bacteremia. Since having bacteria in the circulation is the perceived avenue for late prosthetic joint infection (occurring at least three months after prosthetic placement), this recommendation seems logical. It must be stated, however, that no research has demonstrated that healthy oral tissues prevent PJI. Good oral hygiene and prevention of dental disease could decrease the frequency of bacteremia from daily activities and may protect against PJI. One must remember, developing a recommendation to give AP before oral procedures to prevent associated bacteremia formation and PJI when research does not demonstrate the practice to be successful, is not an evidence-based clinical decision.

Conclusion
The 2015 development of clinical guidelines for dentistry (ADA alone) clarifies the confusion that resulted from the 2012 ADA/AAOS guidelines. "The 2014 Panel judged with moderate certainty that there is no association between dental procedures and the occurrence of PJIs." The Panel stated there is no recommendation for AP prior to oral procedures for individuals with a prosthetic joint. The Panel made the decision based on results of 3, out of 4 studies, reporting no association between PJI and dental procedures. Since the adverse effects of taking antibiotics injudiciously include the development of antibiotic resistance, as well as other potential infections (antibiotic-associated colitis, candidiasis) this clinical judgment must be based on evidence-based science. The benefits and risks of AP to the patient with a prosthetic joint who seeks oral procedures must be clearly defined. For individuals with a history of complications associated with joint replacement and who will have oral procedures involving manipulation of the gingivae or mucosal incision, medical consultation is recommended regarding the benefit of AP (Sollecito, Abt, et al., 2015).

Antibiotic Prophylaxis: When and Why CE Article Post-Test:
1. Infective endocarditis is also known as? a. Cardioarthroplasty b. Viral pericarditis c. Bacterial endocarditis d. Systemic endocarditis 2. Surgical replacement can be performed on any joint of the body, including hips, knees, ankles, shoulders, elbows, wrists, and fingers. The vast majority of joint replacements involve the knee and the ankle. a. The first sentence is True; the second is True b. The first sentence is True; the second is False c. The first sentence is False; the second is False d. The first sentence is False, the second is True 3. Beyond identifying the specific patient population for whom antibiotic prophylaxis is appropriate, special consideration should be given to the antibiotic dose prescribed to children, as it will vary according to the child's ______. a. age b. previous treatment history c. weight d. religious affiliation 4. The guidelines to prevent infective endocarditis, state, "If the dosage of antibiotic is inadvertently not administered before the procedure, the dosage may be administered up to 2 hours after the procedure." a. True b. False 5. Antibiotic prophylaxis might be useful for patients undergoing dental procedures that also have compromised immune systems (due to, for instance, ______________). a. arthritis b. diabetes c. cancer d. none of the above e. all of the above 6. The possibility that bacteremia from the mouth could cause infective endocarditis was first suggested more than ____ years ago. a. 10 b. 15 c. 50 d. 100 7. Adverse factors associated with antibiotic prophylaxis: a. dry mouth b. c. diff c. colitis d. lichen planus e. all of the above f. A, D g. B, C 8. A concern that dentists have expressed involves patients who require prophylaxis but are already taking antibiotics for another condition. In these cases, the guidelines for infective endocarditis recommend that the dentist select a. Penn-V-K 500 mg b. E-mycin c. nothing else d. an antibiotic from a different group 9. Current science strongly suggests that ____________ and __________ are far more significant risk factors for the development of oral bacteria-related IE than invasive dental procedures a. poor oral hygiene, periodontal disease b. improper brushing, failed dental appointments c. electric toothbrushes, stimudents 10. Congenital heart disease can indicate that prescription prophylactic antibiotics may be appropriate for children. When antibiotic prophylaxis is called for due to congenital heart concerns, they should only be considered when the patient has: a. Cyanotic congenital heart disease (congenital disabilities with oxygen levels lower than average) that has not been repaired (children with surgical shunts and conduits may be included in this group) b. A congenital heart defect that's been completely repaired with prosthetic material (up to six months after the repair) c. Repaired congenital heart disease with remaining defects, such as leakage near to a prosthetic patch or device. d. All of the above