A question that comes up very frequently in my courses and in discussions with dentists is the topic of placing patients on antibiotics when they need a tooth extracted. Just like any thing we do in dentistry, there is not a single answer to this question. The best answer I can think of is… “it depends”!
The first question has to do with why the tooth is being removed. Is the tooth acutely or chronically infected? If we are dealing with a tooth that recently fractured and there is no evidence of infection, and if we are simply removing the tooth with no plan to replace it, then antibiotics serve no purpose. The same goes for routine removal of healthy teeth for orthodontic purposes or for the removal of non-pathologic third molars. In these cases, prophylactic antibiotics do not significantly reduce the risk of postoperative infection and increase the likelihood that, if a postoperative infection does develop, it may be resistant to the first-line antibiotics we normally use for treating dental infections. So, in this scenario, the risks outweigh the benefits.
Now, if the tooth is infected, we need to know whether the infection is confined to the periodontal ligament (PDL) space or whether the infection has spread in to the bone or soft tissues. If the infection is limited to the PDL space, then generally, removal of the offending tooth is all that is necessary. However, if the infection has spread to the bone, and especially in to the soft tissues, then the benefits of treating with antibiotics will outweigh the risks. Generally for infected primary teeth, with a moderate amount of root resorbtion, even with a small area of soft tissue swelling, removal of the tooth alone will suffice. This is because the infection is relatively superficial in the alveolus.
There is an old wives’ tale in dentistry that says that an acutely infected tooth cannot be removed without placing the patient on antibiotics first, in order to “cool down the infection” before extraction. This is a bunch of rubbish, as it is the necrotic tooth that is the source of the infection, and until it is removed, the infection will not resolve. It is like having an infected splinter in your finger. The treatment is not antibiotics, it is removal of the foreign body. The antibiotic is just an adjunct to help resolve the spread of the infection. So, if feasible, the tooth should be removed immediately, and post-operative antibiotics prescribed as recommended above. It is also not a bad idea to give a loading dose of the antibiotic prior to removing the tooth. But, notice I said “if feasible”, because sometimes theory and clinical practice clash. What I am referring to here is that in addition to wanting to get the patient back to health, we also want our patients to like us. We learn from experience that local anesthetics do not work well in infected environments. The lower pH in infected regions reduces the efficacy of the anesthetic drug. It may not be possible to remove the offending tooth without causing the patient great discomfort, which is something we all would like to avoid. We would like the patient to return for their next visit and to maybe refer a friend or two.
This is especially true when dealing with an endodontically treated lower molar, for example. So, in real life, as long as it does not place the patient at risk, rather than immediately extracting the tooth, I will sometimes place the patient on antibiotics and then schedule them to return for the extraction in a day or two, when I know that I will be able to get more profound local anesthesia (or in my practice, do the procedure under general anesthesia). If there is a fluctuant swelling, I may elect to do an incision and drainage procedure at that initial appointment in order to make the patient more comfortable and prevent further swelling, abscess formation, and spread of infection. It also reminds them that they need to return to you for definitive treatment. This goes a long way to be able to provide a positive experience for the patient, rather than one they would like to forget about. In the maxilla, it is generally easier to get adequate local anesthesia, especially when using articaine for infiltration. So, that may make immediate removal of the tooth a more likely scenario.
A specific dental infection that earns its own category is pericoronitis. With most odontogenic infections, it is the diseased tooth that is the source of the infection, so the primary goal of treatment is to remove that source, either by extraction or endodontic therapy. With pericoronitis, it is not the tooth itself, but rather the surrounding soft tissue operculum that is the problem. The tooth is generally vital and otherwise healthy. With this clinical entity, immediate removal of the tooth is the worst thing to do. It is imperative that the patient be placed first on antibiotics and the infection brought under control with the help of local measures, such as frequent saline rinses and irrigation under the operculum with an irrigating syringe. This is because manipulation of the tooth right away will most likely result in spread of the infection through the soft tissues and possibly to the lateral pharyngeal and retropharyngeal spaces. This can lead to a serious medical situation where hospitalization may be necessary and the airway might be compromised. Depending on the severity of the infection, I will have the patient on 1 – 3 days of antibiotic treatment before scheduling for removal of the offending tooth. It is also acceptable to use laser or electrocautery to remove or reduce the operculum initially, to make the patient more comfortable and make the area easier to irrigate. But, this is only a very temporary measure before the tooth is removed. In very severe cases, where the patient has notable trismus, difficulty swallowing, airway compromise, or appears toxic, hospital admission, intravenous antibiotics and immediate surgical management is in order. Luckily, this is a rare event.
Now, so far, I have been discussing how to manage these clinical situations in relatively healthy young patients. Throw in some medical complications and we have to modify our treatment plan. Generally, in older patients (the cut-off gets higher the longer I have been in practice) I tend to be more cautious. The capacity to fight an infection diminishes with age. So, whereas in a patient in their 20s or 30s with an acute dental abscess confined to the socket will do just fine after the tooth is removed, I have seen quite a number of patients in their 70s and 80s who returned with problematic infections after the same treatment. So, my bias now is to cover all older patients with antibiotics perioperatively, even with seemingly minor dental infections. The same holds true for patients with diabetes. In dental school and residency, we were told that non-insulin dependent diabetics could be managed just like any other healthy patient. My experience from clinical practice is that they are also at increased risk of problems, just like a poorly-controlled insulin-dependent patient, although to a lesser extent. Again, in my practice, this group also gets perioperative antibiotic coverage as a routine.
So you see, the answer to this simple question is not so simple. The bottom line is, management of a surgical problem requires the clinician to “think like a surgeon” in order to provide the best care for their patient. Not only does the clinical situation need to be analyzed, all the patient variables need to be considered in deciding management.