Dental implant clinicians are confronted daily with the question, “Should antibiotic prophylaxis be provided for a given surgical case?” If antibiotic coverage is considered necessary, then when should it begin and how long should it continue? As prescribers, we do have a “global” obligation for responsible antibiotic use. The purpose of this Editorial is to provide guidance regarding these questions.
Antibiotic resistance is of considerable threat to the management of infectious diseases, because infectious disease treatment is dependent upon having effective antibiotics.1 It is well documented that there is a direct connection between antibiotic resistance and antibiotic consumption.2 Every time we prescribe antibiotic prophylaxis for a patient, we must ask: (1) What are the reasons for giving an antibiotic? (2) Why is an antibiotic necessary? (3) What is the correct timing of the antibiotic administration? (4) How long should the antibiotic be taken?
Two factors to evaluate when performing oral surgery include the following: (1) the invasive nature of the procedure to be performed, and (2) the patient's risk profile.3 These 2 factors will guide the clinician in determining how likely the patient is to acquire an infection of consequence. The infection related issues are as follows: (1) occurrence of a transient bacteremia and (2) surgical site infection (SSI).
Bacteremia may be an issue for some patients because incised gingival tissues produce a transient bacteremia typically lasting <15–30 min following tissue closure.4 This transient bacteremia may not be of consequence in a healthy patient.5 However, high-risk patients are of concern. Patients at risk include those who are immunosuppressed (due to immunosuppressive medications, transplants, current cancer chemo- or radiotherapy), and those with inflammatory diseases (eg, rheumatoid arthritis, systemic lupus erythematosus), diabetes mellitus type I, cardiac conditions susceptible to subacute bacterial endocarditis (SABE), malnutrition, hemophilia, previous prosthetic joint infections, or uncontrolled associated pathologies such as renal, hepatic impairment, and splenectomy patients. Antibiotic prophylaxis is necessary for these patients. Some clinicians believe that for these patients, a regimen of amoxicillin with clavulanic acid is the most appropriate prophylaxis.6 For SABE prophylaxis, clinicians should follow the American Heart Association recommendations.
Invasive procedures that rupture biological membranes are considered a higher risk of SSI or bacterial dissemination throughout the body.3 Depending on the degree of soft- and hard-tissue manipulation, dental implant placement surgeries may be included in this category. Unfortunately, published studies do not always differentiate between degrees of invasiveness regarding implant placement. Thus, a consensus on prophylactic antibiotic use in normal, healthy patients receiving implants cannot be clearly defined.
We know the following to be true: transient bacteremia does occur with tooth extraction, and therefore, is likely to occur with implant placement. Salgado-Peralvo et al7 found that the use of one presurgical prophylactic antibiotic dose reduced early implant failure rates for one-stage implants and also reduced the bacterial load of grafted bone particles in bone augmentation procedures with one- or two-stage implants. Esposito et al8 performed a multicenter placebo-controlled, randomized, clinical trial comparing single dose 1-hr preoperative amoxicillin 2 mg vs placebo. No significant statistical difference in implant success was observed between the two groups; however, trends clearly favored the antibiotic group.8 Braun et al9 performed a meta-analysis for various prophylaxis regimens. They found that implant success was statistically greatest for groups receiving a single preoperative antibiotic dose vs those receiving pre- and postoperative doses. Although definitive recommendations could not be elucidated, findings did suggest that antibiotic prophylaxis might reduce implant failure. However, they further concluded that indiscriminate use of antibiotics in healthy patients receiving dental implants may not be warranted.99 Classen et al10 found that a single antibiotic dose administered 2 hr prior to surgery produced the lowest rate of SSI infections. The peak antibiotic serum concentration should be maximal at the time of the incision and at least 3 or 4 times the minimum inhibitory concentration (MIC) necessary to inhibit the growth for 90% of the bacteria.10,11 Some protocols suggest that for orthognathic surgeries lasting more than 2 hr, a second antibiotic dose should be administered.12
It has been recognized that a one-time preoperative dose in heathy patients may be as effective as a 5-, 7-, or 10-d regimen.13 One preoperative dose is considered prophylaxis, where an extended postoperative regimen is not true prophylaxis, but rather crosses over to therapeutic administration. At the time of incision, the antibiotic serum concentration should be 3–4 times higher than the therapeutic concentration and cleared from the serum within 24 hr of tissue closure.
Intraoperative bacterial contamination can result in an SSI. Prevention of bacterial invasion can be reduced 97% with two consecutive chlorhexidine gluconate 0.12% rinses.14 Two successive povidone-iodine rinses for 30 s (separated by 2 min) has been shown to significantly reduce postoperative bacteremia.15 It has been hypothesized that either perioperative contamination or concomitant localized plaque, gingivitis, or periodontitis may interfere with osseointegration and lead to implant failure.16 Because the oral cavity is a contaminated area, some clinicians believe that infection control during implant surgery (a clean-contaminated surgery) is not possible. This belief does not take into consideration the differences between contaminations resulting from native surgical-site bacteria vs foreign or exogenous bacteria arising from sites other than the surgical-site.10 The goal is to avoid introducing foreign bacteria to the surgical site.
Therefore, clean-contaminated sterility techniques should be maintained throughout procedures to prevent surgical site contamination with exogenous or foreign bacteria. This protocol has been shown to reduce the risk and occurrence of postsurgical infections.10
Despite over 1000 PubMed publications related to the topic of surgical prophylaxis, the need for antibiotics with implant placement remains controversial. The 4th EAO Consensus Conference of 2015 concluded that in “straightforward” cases, antibiotic prophylaxis has not been shown to be beneficial. However, for “complex” cases, clinicians should consider antibiotic prophylaxis.17 Complex cases include patients requiring (1) extensive surgery, (2) prolonged procedures, (3) immediate placement in extraction sockets, and/or (4) patients who are medically compromised. If there is an indication for the use of antibiotics beyond a single preoperative dose, the clinician should provide proper documentation of infection or notation that the patient is immunocompromised.
Considerations for the clinician are as follows:
For simple implant cases in heathy patients, it is unlikely that antibiotic coverage is necessary, but if antibiotic coverage is provided, it should be a single preoperative dose 1–2 hr prior to surgery at a dose 4 times the normal therapeutic dose.
For more invasive implant cases, a single preoperative dose may be beneficial 1–2 hr prior to surgery at a dose 4 times the normal therapeutic dose. For surgeries lasting more than 2 hr, a second antibiotic dose should be administered. Postoperative antibiotics may not be necessary.
For medically compromised patients, preoperative antibiotics would be necessary with possible additional postoperative antibiotic coverage.
As clinicians, we are faced with daily challenges and are obligated to provide the best evidence-based care possible without putting patients at undo risk. Prophylactic antibiotic coverage beyond a single preoperative dose may be without benefit. Extended antibiotic coverage carries the risk of propagating antibiotic resistance, emergence of a nonsusceptible bacterial infection, inducing allergic reactions, or side effects that outweigh any undocumented perceived benefits. Prudent antibiotic prescribing is the responsibility of all implant surgeons.
