The New Medical Rulebook: Treating High-Risk Patients Safely

Dr. Melissa Seibert: Welcome to Dental Digest. This is a podcast with a mission of enabling you to stay on the cutting edge of evidence-based dentistry. I'm your host, Dr. Melissa Seibert. Dr. Natalie Trehan is back for Part 2. Dr. Trehan is an assistant professor at the Medical University of South Carolina and an oral medicine specialist with a focus on systemic disease, chronic pain, and the oral-systemic connection. She completed her residency at the University of Pennsylvania and is actively involved in both academic research and patient advocacy.

In the second half of our conversation, we shift into highly practical clinical decision-making. We discuss how to manage medically complex patients through diabetes, hypertension, and chronic pain conditions, and how to think through treatment thresholds, risk assessment, and when to coordinate care with physicians. We also dive into antibiotics, evolving clinical guidelines, and how rapidly changing recommendations can impact everyday practice. Finally, we zoom out and talk about the bigger picture — why dentistry needs to be more integrated into medicine, and how dentists can take a more active role in managing patients' overall health.

Dr. Seibert: Okay, let me ask you this — getting a little more left-brain. We talked about diabetes. What role do dentists practically play in the management and support of diabetes? I really appreciate your career trajectory because it's making abundantly clear that oral health is systemic health. I'm not sure at what point in history we decided that it wasn't. The oral cavity is the beginning of the GI tract — it's just as much a part of the body as anything else. I'm not sure why we have woefully separated the two. And the last time I checked, there's substantial data showing that oral health has a two-way relationship with the management of diabetes. If we help to get someone's periodontal condition under better control, this can improve their A1C. Vice versa — if oral inflammation goes unchecked, their A1C can increase. Can you speak to what the current evidence shows?

Dr. Trehan: That was a great segue, because the diabetes guidelines — the endocrinology associations — actually just came out with new guidelines for diabetes this year. In the last two months I would say, they updated their diabetes guidelines. This year has been a year of guidelines. A lot of new guidelines have been updated — I think there were like seven this year. I've just been sending them to our associate clinical dean. For diabetes specifically, one of the guideline changes is that they actually now recommend, in writing in their guidelines, that diabetic patients should be seeing their dentist. This is something we all know, we all say, but now it's actually in writing. So that was one of the big shifts, which is really appreciated — that endocrinologists are advocating for us. And as you're saying, oral health is systemic health. I absolutely believe that.

With that being said, on A1C and everything — I don't know how specifically in private practice it works, but at institutions we tend to use the limits in the guidelines for diabetes. So if I have a patient who has an A1C over 9, we're going to just do emergent treatment on them. We're not going to really do anything elective at this time. By emergent, I mean: is anything going to compromise their health? Do they have a decayed molar? Do they have decay or a cavity that is going to lead to some kind of systemic inflammation or affect their heart and go into their bloodstream? We want to deal with that. Or is it something like they want veneers, or maybe they need tooth whitening — we're going to wait on that until your A1C is a little bit more calmed down.

And talking about boards too — that one answer they always look for is, "how does diabetes affect the oral cavity?" Like, what does it slow? And it's infection and wound healing. So with these patients, with that out-of-control A1C — and by out of control, I mean: an A1C can be greater than 9 but be steady. That's your range where you're saying maybe I might not always want to treat that patient with elective care, but I could give them emergent care if they're staying at that 9 for a while and it's consistent. But if they're 9 one day, 10.5 the next month, 14 the next, then 9 again, then 6, then 13 — that is an uncontrolled A1C. I would rather treat someone at a baseline 11 for two years than someone who's flip-flopping up and down. That means it's not under control.

A1C is a reliable indicator because it's giving us an average over three months. But at the moment you're going to do something, you are looking at that POC glucose — point-of-care glucose. That's something we have the luxury of being able to take at a dental school and in the hospital. And it's something I highly recommend any dental practice get. If you don't have one, get it. It's so easy to just take it and be sure what their glucose is before you're starting a procedure. Because if a patient tells you "okay, my POC glucose was 200 or 129" — okay, when did you eat? Were you more stressed today versus previous days when that's been the range? Whereas if I know I'm going to do an extraction or an SRP and I take that POC glucose when they're in my chair, I know exactly what their level is. Point-of-contact glucose — when you prick their finger at that moment and it tells you what the glucose level is at that time.

They're not that expensive. I could be wrong, but I think they're like $30 and you can get them in any drugstore. You get the little cards and you can tell at that second — you just take their blood from their finger and you can tell at that moment what their glucose is. The other thing we also carry — they usually say carry juice, but juice expires. So I really like the artificial glucose packets. They last like three years. They don't taste great — they taste like strawberry. I'm a firm advocate of trying whatever I'm prescribing myself, so I know what we're doing. It does not taste great, but it works like a charm when they're in the chair and they're going to pass out. We give them that if I know they haven't eaten anything.

In terms of someone who has a very high A1C but needs dental work — I would loop in the endocrinologist. Okay, they have an A1C of 13, maybe, and you really need to do this extraction because it is absolutely going to get worse and it's severely compromising their health. Maybe we're going to put them on antibiotics, and that's a conversation that the dentist and the endocrinologist should be having — maybe we're putting this patient on antibiotics and making sure that the glucose control is back to normal for them as well. I'm a very firm believer that we should be talking to other physicians, no matter what the condition is — whether it's sickle cell or diabetes or hypertension. We should always be advocating and talking to their other physicians, because we're part of the team too.

Dr. Seibert: We talked about generally the cutoff for A1C being 9 and above for elective care. But what about scaling and root planing? That can really potentially improve their A1C.

Dr. Trehan: That can. Most school guidelines tend to follow that 9 as the range. If you're doing it when it's above 9, you want to consider a couple of things. Any invasive treatment — meaning any manipulation of the gingiva and tissue, not including just an injection or orthodontics — for any invasive procedures, I would focus more on antibiotic coverage. Again, this is a discussion to have with the endocrinologist, because how many appointments are you going to keep putting them on antibiotics for? That's a slippery slope. But they're not going to be healing well if their A1C is 14.

I've seen sometimes labs that just said "14 plus" — they didn't show the actual number because it was that high. I was like, oh, that's the first time I've ever seen 14-plus. At that point I said, okay, we need to get your A1C under control. As much as clearing out the dental infection and doing an SRP is going to help you, we need to get the A1C to at least a 12 or an 11, and then we can start doing some work. That's where the balancing act lies — yes, we're a physician in our own right, and at the end of the day the responsibility is on us if they end up with an infection. But it's also part of their overall systemic health. So that conversation with the endocrinologist of, okay, do you think it's reasonable in the next two to three months we can get it from a 14 to a 12? Then maybe at that 12 is where I'll do more work, or maybe I'm going to be breaking up the appointments. We're not doing everything, so that they can heal better — because at that stage they're not going to be healing well at all. They are going to be prone to more infections too. So again, the conversation about antibiotics to protect them during that time. And lifestyle modifications as well.

For patients with diabetes, things I also consider: shorter appointments, and then it depends on what medication they're on. If they're on insulin — is it long-acting or short-acting? If it's long-acting insulin and they took it at night, that's going to kick in in the morning. Is the best time to do an early morning appointment when their blood sugar's going to tank? Or should we do it more in the afternoon when their blood sugar is coming back up and they might not pass out in my chair? If it's short-acting insulin — am I going to do the appointment at the same time their short-acting kicks in, when their blood sugar is going to tank in my chair, and I'm manipulating the gingiva, giving them epinephrine and other things? Or do we manage it and move them to a later afternoon appointment? Those are things I consider with these patients.

Dr. Seibert: Fair. Okay — you brought up the topic of antibiotics. Can we briefly talk about when antibiotics are appropriate to prescribe and when they are not? When I was a dental student at the University of Louisville — shout out to the Cards — narcotics were a big issue. I had a lot of lectures about drug-seeking behavior. Honestly, in my career, I think I've had maybe one or two people I potentially suspected of drug-seeking behavior. I just don't see it as much. But antibiotic-seeking behavior — oh my gosh. Patients want that stuff, and they will view you as practicing substandard care if you do not write them an antibiotic.

Dr. Trehan: I agree with you. I've only had a few patients who want opioids. I don't prescribe them primarily because it's a lot of work to prescribe them and monitor everything, so I send them to pain management. I have a lot of chronic pain patients in general for facial pain. My colleague is a facial pain person, so I send them over to him. I'm very lucky for that. But yes, antibiotics — everyone wants them now. They take them for everything, whether it's viral, not even bacterial. And with telehealth, you can get them more accessible than ever. I can't tell you how many patients I've had who said "oh, they did a $45 telehealth appointment, they told them they had a UTI, they got the antibiotics." It's more accessible.

I've done it myself where I was coming home from a flight and I'm like — this is viral. But I had also just come back from a trip to India, a great retreat. I had a viral infection and I knew this is viral, this is not bacterial. But my mom said, no, you're flying again to MUSC, you need to just do it through the telehealth. I didn't even say five words and I got a course of antibiotics. I was like, this is not bacterial, this is a viral infection. Why am I getting antibiotics? It's so easy to get it.

There are a lot of conditions we do still give antibiotics for, some we shouldn't be, and some we should be. Then there's the prophylaxis — where we want to give the day of procedure. And then antibiotic cover, where if they have an infection and just can't get into see endodontics or their provider for a few days. Starting with prophylaxis and when we absolutely want to give antibiotics: the Orthopedic Association actually just changed the guidelines again this year, in October. They have now agreed with us as dentists, which is what we were saying all along. I have never in my career been the one to prescribe antibiotics for a patient with a joint replacement. There are a couple of patients whose orthopedic surgeon gives it to them, fine — but I have never done that.

I give it in the first six months post-procedure. And within the first two years, if they had an infected joint — knee replacement where the prosthetic joint was infected, or they had to have a redo because of infection — those are the cases I will definitely give it. That has continued — that's what the guidelines say. The guidelines also confirm what we had been saying: that their activities of daily living, like brushing every day, kick up more bacteria than us doing a procedure in a clean, sterile environment. If a physician — the orthopedic surgeon — wants to give the patient antibiotics, I'll tell the patient, "You can do that. We don't really recommend it 10 years out or 20 years out after a completely normal knee replacement. But if your physician wants you to take it, you can. Just so you know, that isn't the policy of the school or for us — our guidelines also don't believe in it, but if they want to do it, they can."

Dr. Seibert: Where can people find these guidelines?

Dr. Trehan: This is the American Academy of Orthopaedic Surgeons. It actually literally just happened. There's a project that one of my colleagues is having students read it — he's like, hey, so Dr. Trehan shared this, now this is your project, tell us what these guidelines mean. I think it's great because we had a conference a few months ago and a dentist came and was like, "so when did we stop giving clindamycin?" And we were like, "in 2007 — it's been a minute." And he was like, "oh, I didn't know." And, "when did we stop for mitral valve prolapse?" And we were like, "same time." And he was like, "no, I didn't know." I was like, well, you've gotta keep up with the guidelines, sir.

Dr. Seibert: So tell us this though — let's get really practical here. There are a lot of hardworking dentists in private practice. How do they know that guidelines have been updated?

Dr. Trehan: That's the thing. At my school, I'm the person who keeps up with the guidelines. You need someone who is on top of guidelines to be sending out: "these are the guidelines that are changing." Otherwise no one knows the guidelines change. They don't announce it unless you're at those conferences. I think the best way to do it — I told my students — is to get a group of your peers and your alumni and be like, hey, listen, we need to keep on top of the guidelines. Someone needs to, and take turns. Maybe one person's going to focus on knees, another on endocrine, another on rheumatology, derm — whatever diseases you want. They kind of look out for that, because unfortunately there's no central database for us. I don't even think the ADA has updated it. I'm just checking the ADA website. The last one is by one of my mentors, in 2015. This is something the ADA could really be doing to serve the dentists that pay memberships.

Dr. Seibert: Well, first of all, when guidelines change, you'll have to notify me, and then I'll notify the dental community.

Dr. Trehan: I will. Oh my God, I'll send you all the seven I've sent out to my school. I usually make a one-pager.

Dr. Seibert: Put me on that distro list.

Dr. Trehan: I'll make a listserv. Maybe I should actually do that. This year they've been: diabetes, hypertension, CPR, orthopedics, the knee replacement, lupus. I think five or six guidelines in the span of September to December. I freaked out.

Dr. Seibert: How have the CPR guidelines changed?

Dr. Trehan: Basically they now follow the European guidelines — if you had a baby, they do thumb CPR rather than fingers. That was one of the main changes. Further emphasis on having naloxone — everyone should have naloxone in their offices. And then the other one was the positioning, even the positioning for chest thrusts and back blows changed for babies and infants. Those were the three: naloxone, the positioning, and the thumb technique for infants.

Dr. Seibert: Let's talk about clindamycin.

Dr. Trehan: Yes. So for clindamycin — and any of your listeners who are taking their boards: do not click clindamycin. It is not the right answer on your theoretical. I tell my students the same. Theoretically, there are going to be answers that are different theoretically versus in clinic, what the real-life decisions are.

Clinically, clindamycin is the last option I give patients. It's when they're allergic or cannot tolerate any of the other options and they have tolerated it in the past. There's a lot of controversy about the use of doxycycline, which is the one that replaced clindamycin, because doxycycline is not super broad-spectrum and doesn't really target the oral bacterial infections we have. And the dosage is 100 milligrams — that's not really going to resolve anything. So I personally, and a lot of my colleagues, will put clindamycin above doxycycline on our list of things to give. But I would still rather give something like azithromycin or cephalexin instead.

Dr. Seibert: Because if I'm not mistaken, there's very low cross-reactivity with azithromycin, right?

Dr. Trehan: Yeah. So if they're allergic to amoxicillin or to penicillins and we can't give them amoxicillin, my go-to is azithro and then cephalexin. Cephalexin can have a little bit of cross-reactivity. If they've had a history of angioedema, you tend to not want to give cephalexin.

Dr. Seibert: So to recap — is it azithromycin or cephalexin that's preferred if they're allergic to penicillin?

Dr. Trehan: Azithro. It can be both — they're technically both on the list. I think it's provider preference too. I just like azithro, to be honest. So I tend to say azithro first and then cephalexin, because cephalexin also can have cross-reactivity and azithro tends to have less of it.

Dr. Seibert: Fair. As a final topic, hypertension. Lots of misconceptions. Patients come in, they have elevated blood pressure — it feels like everybody has elevated blood pressure. When should you delay elective treatment? When should you delay even emergent treatment?

Dr. Trehan: What I want to tell you is the new updated hypertension guidelines that came out. 2025 AHA, ACC — the American Heart Association and American College of Cardiology — had new hypertension guidelines. They're not a lot of changes, but to sum them up: changes to screening of blood pressure, the classification, the management thresholds, and pregnancy-specific considerations.

They changed the treatment goal overall for patients — now under 130 over 80. Previously it was 120 over 80; now less than 130 over 80. They also changed some terminologies. We used to call it "hypertensive urgency" or "hypertensive crisis" — we just call it "severe hypertension" now, and that's greater than 180 over 120 with no acute target organ damage. So no kidney involvement, no heart involvement, no vessels, no brain involvement.

For us in dental school — and most people tend to practice it — screening at every visit. We measure blood pressure at every dental appointment. Use validated devices and proper techniques, making sure the cuff fits, because that can give false positives. Repeat if elevated, but wait 15 minutes before repeating. Then in terms of actions by category: if it's less than 160 over 100, we proceed with dental care. If it's 160–179 over 100–109, we proceed with caution, but minimize stress and consider notifying the physician or telling the patient to notify their physician. When it's greater than 180 over 110, which is severe hypertension, we defer elective treatment and refer for medical evaluation. That just means establishing care with the physician — not that they need to go to urgent care or the ER right now. If it's greater than 180 over 120, we want an immediate referral. If there's no acute target organ damage, we'll do an urgent referral but still outpatient management.

We get a lot of patients who recently — there was one Tuesday we had 19 patients from 1 to 2:30 PM. It was a crazy day, and we had eight of them coming straight from the ER, and another eight we were sending straight back to the ER because their blood pressures were 220 over 180 or 203 over 140. We were like, "Sir, even though the guideline says we have to send you to a regular place, we're sending you back to the ER because these are not okay conditions." The patients are the ones who are chill about it — it's all of us freaking out. We've had patients almost pass out in the chair too because it's been so high. We'd ask clinical signs — okay, do you have a headache? Chest pain? Shortness of breath? Loss of consciousness? Those are things you look for. If they have greater than 180 over 120 with those symptoms, I wouldn't just go for an outpatient referral for family med or internal med. I'd send them to the ER and stop everything.

Dr. Seibert: Okay. So 180 over 120 if they're symptomatic — send them to the ER. If they come in with a bona fide emergency, are at 180 over 120, asymptomatic — safe to treat the emergency?

Dr. Trehan: I think that's a judgment call. Do you feel comfortable? Our cowboys in oral surgery sometimes definitely do. Our oral surgeon colleagues will be like, "yeah, we're limiting the amount of epinephrine, their blood pressure is elevated because of the pain." And I have experienced that. It's not okay if they're like 200, but if they're 180 over 110 or around that range and there's a pain component, let's eliminate the pain and then send them for an evaluation. By non-symptomatic I mean no chest pain, no shortness of breath, no symptoms from their hypertension — we're not thinking they're going to have a stroke or heart attack in our chair. But I would get them out of pain, because pain increases blood pressure.

Dr. Seibert: Do you ever think it's conceivable that dentists feel uncomfortable understanding hypertension and elevated blood pressure, so they defer and delay more treatment than necessary? There was a guest who came on the podcast probably five years ago — when this really started. He wrote an article featured in the Journal of the American Dental Association. He was a cardiologist. He talked about this phenomenon, just how sick he was of getting referrals from dentists where the dentist wasn't recognizing false positives. Just like you said — they weren't using a validated device, they were improperly measuring blood pressure. Patient hassles into the appointment, had a ton of caffeine, legs crossed, talking a lot. Then they get elevated blood pressures. He was talking about it very professionally, but basically: dentists are inadvertently not making good use of our physician colleagues' time, because we're not recognizing false positives.

Dr. Trehan: I think that's reasonable. I also think, on the other hand, most people discover they have bleeding disorders and hypertension in the dental chair. If we then become overly cautious, are we going to stop helping people get their diagnosis? That would be my devil's advocate moment. I do think we should validate things more — check it twice, then maybe send it to our colleagues. Recognize that yes, pain might play a role. But if we start becoming overly cautious and people say "oh, stay in your lane, you should not be sending these over" — then we're again not treating as part of systemic health.

Dr. Seibert: Oh my gosh, one of my pet peeves. I'm not even going to tell specific stories — but one of my pet peeves is when physicians will say the "stay in your lane" card. We have an obligation to educate ourselves. Don't waste anybody's time. Send validated things over. Stop sending patients with tonsilloliths on a panoramic radiograph. Stop sending them over for calcified carotid arteries. Know what you're sending. Educate yourself. But once you really educate yourself, you're not wasting anybody's time. There should be collegial dialogue there.

Dr. Trehan: I absolutely agree. Some of my colleagues are brilliant — they're facial pain doctors. One of them, like a year ago, was the one to diagnose a patient with trigeminal neuralgia. We've diagnosed that too in different cases. She sent them back to the neurologist because they wanted to be in contact. The neurologist was basically like "yeah, so stay in your lane" — and she diagnosed it. What are you talking about? You missed it. This was diagnosed through her, because she ordered the MRI. You didn't. That's how it was caught. I've seen that so many times. We need to just all work together and help each other advocate for our patients.

Dr. Seibert: Yeah. I wonder what it would take to enable more crosstalk between physicians and dentists. I have no idea. That is a lifetime of an effort, but I would love to see it happen more.

Dr. Trehan: I think that's been happening — at least within my specialty, which I really appreciate, because oral medicine is the interconnection with medicine and dentistry, especially hospital-based medicine. I do a lot of work with my colleagues and they've been nothing but nice. I lecture to them and teach them about oral manifestations of so many different diseases. I go to their conferences, to the residents, to their faculty meetings. I get invited to speak on all these different topics because they say "we get one slide in med school, and this is the mouth, and that's it." One of my friends is in med school right now, and one of the questions on her exam was "what was the 2019 Surgeon General's recommendations for dental health?" She was like, "why was that a question?" I was like, I couldn't answer that question. It should have been about oral health and systemic health.

With my specialty in general, which has been there for ages — I've been greatly mentored by some of the greats who've written textbooks and lectured at all the CEs — being recognized as a specialty in 2020 has changed things. We need a dentist or oral med person or facial pain or one of these specialties in every dental school and every hospital, because that's what opens up the conversation. And GPR programs — if we can't have specialists, having a GPR program at hospitals, having a dentist, is so necessary. With the VA and with the hospital, that opens up the conversation.

Dr. Seibert: One hundred percent. Forgive me, I just looked at the time and realized we're out of time. You are amazing. You're such a light in the profession. I'm so glad you came on. What are your closing remarks?

Dr. Trehan: I really appreciated this conversation. Thank you so much for having me on. I hope this opens the door for more conversations like this — continuing to advocate for our field in both of our different ways, and that oral health is systemic health. This definitely has to be a two-way conversation. I'd encourage dentists to bring up dental implications of systemic health to their patients, because their patients are not always sure what's going on. Let them know about the link between oral and systemic health, and then open up the conversation with your patient's physicians too. We need to make it a two-way street and show that we are part of that conversation — not just "oh, you're tooth mechanics." No, we're part of overall health, and we need to own that as well.