Antibiotic prophylaxis for dental procedures: an update

[Music] Welcome to the Australian Prescriber Podcast, an independent no-nonsense podcast for busy health professionals.

I'm Dhineli Perera, your host for this episode with Dr Smitha Sukumar about the 2025 Therapeutic Guidelines revised antibiotic prophylaxis for dental procedures. Smitha is a senior lecturer at Sydney Dental School at The University of Sydney. She's also the lead of the oral microbiome research stream at the Charles Perkins Centre, also within The University of Sydney. Smitha, together with her team, revisit the indications for antibiotic prophylaxis, delving just a little bit more into the details and to help us elucidate who really needs prophylaxis and for what. A warm welcome to you, Smitha.

Thank you so much for having me.

So Smitha, for those of us that aren't aware of the risks involved with everyday dental habits, could you please talk us through the incidence of transient bacteraemia with home dental practices versus other minor dental procedures in the clinic?

So one of the interesting things that we've learned over the last few decades, and we are really learning much more about this with the increased technology available to us through microbiology, is that transient bacteraemias are actually far, far more common than we've previously thought, and they are associated with everyday oral hygiene practices.

So essentially, every time we brush our teeth or floss, use interdental brushes or toothpicks, hopefully nobody's using them, bacteria can enter the bloodstream for a short period of time. So it happens every time we are cleaning our teeth. Dental procedures that manipulate the gums also do the same thing. All the bacteria, and there's a lot in our mouth, is flooding through the bloodstream, it moves around the body. But because we're not seeing the dentist every day, this is a relatively infrequent activity compared to what we're doing on a daily basis.

What we need to be worried about is what is somebody's day-to-day health looking like? So if you've got poor oral hygiene, your gums are swollen, you are going to have a greater experience of this bacteraemia every time you brush your teeth. So it's that cumulative exposure that matters. One of the best ways to reduce risk, particularly for patients who are at increased risk of infective endocarditis, is thinking about maintaining good oral health. So what they do every day really counts.

So if it's the everyday dental practices at home that even do this transiently, patients that have the risk for endocarditis are probably the ones to be more concerned about this. Is there something that they can do to prevent it from happening besides the basic sort of keeping your gums healthy?

Yeah. So if you have a patient where we know that they're at an increased risk of infective endocarditis, obviously, we know that if we're going to do a procedure that involves their gums, we have to give them antibiotics. But what we also have to be doing is talking to them about preventive home care. So this is not something that it's just looking after the gums and the teeth. This comes back to talking about everything. Are you well hydrated? What's your diet like? What people really need to be constantly reminded about is, what are we doing overall? Because it's not just about their dental health outcomes, it's about their whole health and oral health is part of that.

Absolutely. Thank you so much for that. Probably something that a lot of our listeners, myself included, I wasn't really aware that this was even a thing with your everyday home practices. Table 1 in your article lists dental procedures that do and do not require surgical antibiotic prophylaxis. Could you walk us through it? Because I feel like this is probably the most important part of your paper.

Yes. So I think the key message from the table is that most routine dental procedures do not require surgical antibiotic prophylaxis. Just going through procedures that dentists are doing on a daily basis like extractions, third molar surgery, implant placement, soft tissue biopsies, these do not require antibiotic prophylaxis. And that's really, really important. And the reason for that is if we're thinking about preventing infection, so we think about postoperative infection rates, this is typically very low, 1% to 2%. This is for things like third molar extractions.

And so what you then have to think about is, I'm trying to prevent an infection, which is a very low chance of happening. I'm going to give antibiotics where we know we're going to get resistance. So we have to think about this risk–benefit. And we've got plenty of evidence over many years to show us that. But saying that, prophylaxis is still recommended for specific major oral and maxillofacial procedures, but a lot of these procedures are being done in the hospital with specialists. So this is with max-fax [maxillofacial] surgeons. So for the general practitioner, this is not really a major concern.

Are there specific procedures from the list that you would like to highlight or any myths to bust? For example, are there procedures on that not required list that you know in practice patients have routinely been given prophylaxis for?

Absolutely. So I'd say the biggest myth is around wisdom teeth requiring antibiotics. You hear this from patients all the time. They'll say, 'Oh, yes, I had my tooth out and it was this terrible procedure and then I got antibiotics.' Almost like, 'Well, because it was so bad, I definitely needed to get the antibiotics.' It's often lost that what we give antibiotics for, it's for infection.

We have this mindset that yes, sure, there's the evidence and these are the guidelines, but on the ground when I'm doing things, it's just a lot easier. You don't have to worry about my patients. If I just give the antibiotics, I'm going to be okay. So this 'just in case' attitude, especially around things like wisdom teeth. The other area I'd say it's implant surgery where antibiotics are traditionally overused. So this is a foreign body. It's likely that this is not going to go well.

We know titanium is very well accepted in the body. It's very biologically compatible and infection rates again are generally very low. So routine prophylaxis, not recommended for the majority of patients in a community-based setting.

Wonderful. So just for my interest, do you know whether the dental schools have kept up with this newer information? So for example, the newer grads that are coming out, are they aware that this is the case?

Well, I would certainly hope so. So I teach about antibiotic use and antimicrobial stewardship guidelines every time they are updated. All the dental schools will be updating their teaching to align with what the guidelines say. So I would definitely say that they should be leaving knowing this knowledge.

Okay. So moving on to the factor that you've highlighted in terms of the immunosuppressive or immunocompromised patients, I wanted to clarify what was meant by patients who are not profoundly immunocompromised or have high-risk cardiac conditions. Is there somewhere clinicians can go to find out if their patient meets these criteria?

So I think if you're wondering whether somebody is profoundly immunocompromised, if that's even entered your head that this is a concern, that is a sign that you should pick up the phone and speak to the treating specialist. That is the easiest way and it is the best way to get information about that specific patient, which is what we want to know. The guidelines, so TG4 [Therapeutic Guidelines: Oral and Dental version 4] directs clinicians to specific resources such as the Australian Immunisation Handbook. But again, I think the best thing to do, and of course this is in the guidelines, is pick up the phone, have the conversation with the treating team or the medical specialist, and that's really the safest approach.

But what I would say is if you're thinking, 'I don't even know where to start.' So a profoundly immunocompromised patient, these are people receiving intensive chemotherapy. They're immunosuppressed because they've had a transplant, high-dose corticosteroids, or they're on some kind of potent immunosuppressive. We all have seen patients like this. It's just flagging that and then saying, okay, I'm going to pick up the phone and speak to the correct person.

And so this is probably that exception to what we said before where most of the time antibiotic prophylaxis is no longer indicated in the community practice. This would be the group where the exception lies, right?

Absolutely. But you'd only do that in consultation with the medical specialist. If you're going to do it, make sure you've liaised with the specialist team.

Wonderful. So in general then, Smitha, would you say that the evidence out there suggests that dentists over- or under-prescribe antibiotic prophylaxis? Or is it kind of mixed?

So we tend to over-prescribe, and there are lots of reasons for this. A lot of them have to do with human factors rather than looking at the guidelines or you have all the evidence in the world. But as human beings, many of our decisions are made on past experience, emotion. And that's this mentality. If the patient's always had prophylaxis because they've had the joint replacement and they'll come in and go, 'Oh, for the last 15 years I've had antibiotic prophylaxis after I had my knees done.' And you sort of sit there and why? But maybe nobody's had the time to sit down and talk to that patient and say, 'Why are we doing this? What's the reason why you need it in the first place?' And having that discussion.

The patient now thinks something bad is going to happen to their knee if you don't give this. And then God forbid something does go wrong. So then you think, 'Oh, what if there's this medicolegal implication?' And it sort of snowballs from there. And it's the same thing for us as clinicians. Well, I've always given antibiotic prophylaxis when I've placed an implant or I've done my wisdom teeth surgery. So we know, for instance, that 24% of general dentists reportedly, this is a survey done in Australia, and we've included this in the paper, use antibiotics for third molars, and 61% of maxillofacial surgeons do that.

You'd look to the specialist saying, 'Oh, well, they're doing it, so there must be a reason. So therefore we're going to do it too.' TG4 coming out, so the new clown book [Therapeutic Guidelines: Oral and Dental] coming out, that's a big event in dentistry now. People are really aware of this. They are wanting to find out, they're attending events, they're reading it actively. People are talking about it. So there's much more awareness about what we are doing and there's much more of an awareness that, look, we've got the guidelines and we're going to use them.

Yeah. And I think moving to online has probably been a real help with that versus the paper-based. When you're middle of the theatre or your clinic practice, running to the shelf, that is probably less likely to happen versus having it on the computer where you're ready to go. So hopefully most clinicians are having access to that in their practice. And so this is where my limitations of dentistry comes in. I wondered if you could talk us through the difference between subgingival and supragingival instrumentation. Has there been an update to prophylaxis recommendations for these types of procedures?

So the short answer to that is yes, there has been an update to the prophylaxis requirement for subgingival and supragingival instrumentation. And I'll come back to that. The difference between them, so supragingival basically is a very fancy word for above the gum line. So we've got full access, we can see what's going on, and you can take away the plaque, which is the soft stuff, and the calculus, which is the hard stuff.

Of course, we're human beings, so it's not like we can draw a perfect line and say it stops here exactly, it's not going to go under the gum line, because we don't work like that, unfortunately. But when it does fall underneath the gum line, so if that's the subgingival instrumentation, this is a transmucosal procedure. So this is an invasive procedure. Now, you are under the gums. The gums are red for a reason. There's a huge blood supply there, and that's when prophylaxis kicks in.

So to be really clear, the June 2026 update of the Therapeutic Guidelines, the 4th edition, so the latest edition has been updated since it's been released. It no longer includes supragingival instrumentation. So if you are doing purely above the gum line work for cleaning or prophylaxis, that is not an indication to give antibiotics if a patient is at risk of infective endocarditis.

But if it's subgingival, you are?

Yes, that is correct. If you're doing subgingival and the patient is at risk, so the 2 conditions, yes, you have to give prophylaxis.

Right. But subgingival with a low-risk individual doesn't need prophylaxis.

Absolutely not. That's correct.

Wonderful. Thank you for clarifying that. And so when it comes to infective endocarditis risk, which is unfortunately still not a straightforward answer for most people, what is the best way to understand if the patient in front of you is at this risk? What's your method of investigating? And I think this comes back to perhaps a similar process to your immunocompromised patients. Would that be right?

Yes. So again, here, it's very simple. So I'm a very simple person. I've got 2 boxes in my head and 2 of those boxes need to be ticked. So the first box is, does this patient have a high-risk cardiac condition? And then the second box is, am I going to undertake a high-risk dental procedure? So whether I tick or cross that first box, it's a systematic medical history basically. Most of us in practice, that's been filled out by a new patient when they first come in. You do need to go through this with the patient. I know we all do that, but just to re-emphasise, just because they filled the form, it's not going to via osmosis enter our brain. We've got to go through it with them. And sometimes patients forget or get confused about things, especially if they've got lots of medications or lots of things have been going on.

It sometimes means you're reading in between the lines, you're being curious, you're asking questions. But basically, going through that medical history process, you are systematically checking whether the patient fits into one of the guideline-defined high-risk categories. So do they have a prosthetic heart valve? Have they had endocarditis previously? Do they have a ventricular assist device? Have they ever had rheumatic heart disease? And unfortunately in Australia, that still remains a problem. These are the things that we'd find out in the medical history.

Once that's done, then the onus is on us as the clinician to say, 'Okay, is what I am planning to do going to involve gingival manipulation? Am I going to be very deep in the tissues? Am I going to perforate the cheek or the soft tissue?' And if we can say yes to both of those, then go ahead and prescribe whatever the recommended prophylaxis is for that patient.

Yeah. And so then is that the same sort of process you run through when it comes to prosthetic joints?

Yes. Same thing. With the prosthetic joint, you definitely ask questions around, when was the surgery done? I think that's really important. For prosthetic joints, it's 2 years. They have this period for postoperative complications, but if it's within 2 years, everything is fine. Are we really giving this person prophylaxis? Is that necessary? And certainly the guidelines indicate that it's not. The majority of patients don't need antibiotic prophylaxis.

Moving on to avulsed teeth. So I'm going to say that this is a parenting nightmare. Does the management of this require prophylaxis?

I totally agree with you. It is a nightmare for parents and, unfortunately, it's a very long-term nightmare where the shadow of dental trauma goes on and on and on. So this is one of the areas where the guidelines recommend giving antibiotics after the tooth has come out, and that is in line with the International Association of Dental Trauma. However, I would say this is a space to watch because the evidence is not strong at all in this area.

Right. So then moving to the actual antibiotics, I wondered if you could talk us through what antibiotics to prescribe and their relevant timing and comparing and contrasting that between your suburban dental clinic and the hospital. So I think the biggest point there being intravenous versus oral, right?

Correct. That's right. So again, I have some principles here that I tend to follow. I don't memorise any antibiotic prescription. And if I have memorised something that's purely by accident, I consult the guidelines every time. So anytime a patient comes in, I'm online, I'm pinging the book, whatever it is, I'm always looking it up because you might see something and you go, 'Oh, hang on. Is this what I'm meant to be doing? Or do I need to double check something?' Or I've forgotten something. Some people have a great memory, can remember all these numbers and time intervals, but consult the guidelines. There is nothing wrong and we shouldn't be prescribing them so often, so we should be consulting the guidelines. So that's actually a good sign.

The second thing comes to the type of antibiotic you're prescribing and the relevant timing. That's really about the antibiotic which is going to be most effective in reducing the bacteraemia is really what we're looking for. And also, it has to reach the effective plasma concentrations for that to happen. So that's really the biological processes behind what we're doing and that's what we're thinking about. But generally, it's amoxicillin that we use in general dental practice 1 hour before the procedure because this antibiotic and this prescription basically fulfils those 2 needs. It's the correct antibiotic in terms of bacterial coverage and within an hour it's going to hit the right plasma concentration level.

Of course, if you have penicillin hypersensitivity, there are other options and that depends on the type, non-severe or severe. But one of the biggest changes in that area is that we're no longer recommending clindamycin to use as an alternative to penicillin [in patients who require infective endocarditis prophylaxis]. As you said, in terms of the hospital settings, this is again not something that is going to be done by most of us. This is going to be IV (intravenous).

And of course, if they can't take penicillin, there's other recommendations. And that's generally administered 1 to 2 hours before the surgery. But again, this is a very, very different setting. And of course there is much more oversight in these settings than there would be in a general dental practice.

Wonderful. Well, I think the take home from that is to really check the guidelines. Like you've said, I think I do that in my own practice as well, especially when it comes to things that I'm not doing frequently, so paediatrics for example, I check dosing for that all the time. Whereas colleagues I know that can memorise mg/kg dose for everybody. I'm like, 'No, thank you. I'm just going to check that.' I think it's a really good practice. Well, thank you so much, Smitha. That's unfortunately all the time we have today. I really appreciate you joining us.

No problem. Thank you for having me.

Dr Smitha's article, Antibiotic prophylaxis for dental procedures: an update is available on the Australian Prescriber website. The views of the hosts and guests on the podcast are their own and may not represent Australian Prescriber or Therapeutic Guidelines. Dr Smitha has received research funding from eviDent and the RACDS [Royal Australasian College of Dental Surgeons]. She is also a member of the Australian Dental Association DTC [Dental Therapeutics Committee]. I'm Dhineli Perera, and thanks for joining us on the Australian Prescriber Podcast.

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