How Not to Kill Your Patients: Bridging the Gap Between Dentistry and Medicine

Dr. Leslie Fang on why his latest book, The Medical Guide for Dentists Treating Complex Patients, is so critical to the dental community.

Both medicine and dentistry are advancing at break-neck speeds, making it difficult for clinicians to stay current. Medical conditions and their management are increasingly complex, and if dentists don’t understand these nuances—or how they affect dental treatment, which is also growing more complex—they risk compromising patient safety.

Dentists need an expertly written, up-to-date resource that puts essential information at their fingertips. Unfortunately, that can be difficult to find, as many textbooks claiming to bridge the gap between dentistry and medicine are outdated. “Many of these books are at least five years behind, some even more,” said Dr. Leslie Fang, a dental educator and author who is board-certified in both Nephrology and Internal Medicine.

Dr. Fang’s latest book, The Medical Guide for Dentists Treating Complex Patients, written in partnership with Tracey Menhall, fills that gap by providing a comprehensive and current reference. The textbook includes 45 chapters detailing “virtually every medical condition a dental professional may encounter,” Dr. Fang explained, and guides clinicians on what therapeutic modifications may be required when treatment planning.

“The overarching theme of the book is how not to kill your patients,” Dr. Fang said. That has been the focus since the pair, along with Dr. Robert Fazio, wrote the first iteration of the popular, Ultimate Cheat Sheets: The Practical Guide for Dentists. Constantly updated, the resource serves as a chairside tool that keeps dentists up to date on FDA mandates, life-saving algorithms and new drugs entering the market.

“We’re providing the bridge between medicine and dentistry, and that bridge is very difficult to construct by a dental professional writing in medicine or a medical professional writing in dentistry,” Dr. Fang said. “We occupy a unique space, where a few people can do what we do and keep up with developments in both fields.”

What Makes the Book Unique

One question Dr. Fang is often asked is why a nephrologist is writing about dentistry. His interest in the field began years ago when he first met Dr. Fazio at Harvard Medical School. They became fast friends and decided they wanted to do something special after they graduated—something that would bridge Dr. Fang’s medical expertise with the knowledge dental professionals need to keep from harming their patients. That collaboration led to a textbook, which eventually evolved into the Ultimate Cheat Sheets, and now, Dr. Fang’s newest book.

Most authors in this space, Dr. Fang said, simply don’t have a deep enough understanding of medicine to be credible. He does.  

“Seventeen of the 45 chapters contain information no other dental textbook offers, because they can’t keep up,” Dr. Fang said. “They don’t know what changes happened in 2024 and 2025 in terms of managing diabetic patients. They have no clue what the four pillars of managing congestive heart failure are. What we’re writing reflects what medical clinicians are doing in 2025, not 2020 or 1988.”

What to Expect

Every chapter of The Medical Guide for Dentists Treating Complex Patients has the same format: a brief topic introduction followed by a thorough medical evaluation of the disease condition and how medical professionals treat it, Dr. Fang said. The chapters then detail what dentists should focus on in their evaluation, and how, based on the information gathered, to develop treatment plans that ensure they’re taking optimal care of their patients.  

The book also keys in on pharmacology, Dr. Fang said, which is very different than most dental textbooks.

“I’ve spent many years teaching dentists, and they’re very uncomfortable with pharmacology,” Dr. Fang said. “They write scripts daily, but they get used to writing the same ones all the time and don’t know what the rest of the world is doing, or that the ADA put out new guidelines that make what they’ve been doing obsolete. That information is just very difficult to keep current.”

Dr. Fang’s latest book also includes a section on antibiotics and how to handle pre-meds for an array of conditions ranging from cardiac lesions to hardware in the body to infection in the oral cavity. The book ventures into topics “nobody has answers to, but everybody would like to have answered” explained Dr. Fang

For example, dentists placing implants often have questions about antibiotics, including whether they should give patients antibiotics before and after the procedure. There’s currently no answer to this, so Dr. Fang looked at what others are doing around the world. He convened a group of clinicians and came up with a “reasonable consensus opinion” that’s included in the book.

“Nobody else would put that in print, even though it’s a logical solution to a problem that currently has no data,” Dr. Fang said, “that’s definitely different than a conventional textbook.”

The book also covers typical topics like what to ask in a medical history and how to manage patients with common conditions like coronary artery disease and congestive heart failure. It also includes how to treat patients taking newer drugs, such as Ozempic^® and Trulicity^®, as they do have an impact on dental treatment. Dr. Fang has even started lecturing to the dental community about such meds and their implications. Clinicians must find out if patients are taking these drugs before treatment, as they likely won’t think to mention it.

Understanding the Disease States

In The Medical Guide for Dentists Treating Complex Patients, Dr. Fang reviews the importance of taking a thorough medical history.  “You can learn a great deal about the complexity of the medical situation, the severity of the disease, just by looking at the patients’ list of medications,” he said. “If you see meds you don’t understand, you must find out why they’re taking it and what it is.”

It does become predictive, he said. A lot of patients with congestive heart failure, for example, take Jardiance. The first time you see it, you might have no idea what it is, what it does, or its dental implications. But when the next patient comes in with the same medication, you’ll have a much better understanding of how it might impact treatment.

Bottom line: Dentists must understand their patients’ disease states, which are becoming more complex, Dr. Fang said, and how they impact the dental treatment plan.

Staying Current on the Guidelines

In the last four years, the ADA has changed virtually every antibiotic pre-med regimen, Dr. Fang said. Those changes have become the new guidelines. The problem is, if you’re not up to date on the guidelines, you could get into trouble.

“If you do something outside the ADA guidelines, it is critical you actually indicate in the medical record why you deviated from the guidelines,” he said. “You’re allowed to do that, but you must document the thinking process. If you wind up with anaphylaxis and say you didn’t know the guidelines, that looks ugly.”

One of the changes, Dr. Fang said, is clindamycin. It’s been the No. 1 antibiotic for dentists to prescribe to patients with a penicillin allergy for a long time, but, because of its serious side effects, it fell out of favor with the medical community years ago. Dentistry has caught up, with new ADA guidelines now recommending other options. Dentists who don’t know about the guideline changes may still use it regularly, something the medical community wouldn’t even consider.

“That shows a disconnect,” Dr. Fang said. “In medicine, we wouldn’t touch that drug with a 10-foot pole, but in dentistry, they’re using it like they own stock in it. It’s become a pariah on the medical side because it exposes patients to risk. But it takes a while for that information to filter down.”

With other textbooks, information on such guidelines often becomes obsolete before they’re even published, Dr. Fang said. The Medical Guide for Dentists Treating Complex Patients, which was finished in December, is still current and “as up to date as any information is ever likely to be.”

One Size Does Not Fit All

There’s a subsection of dentists who gravitate toward more complicated patients, Dr. Fang said, like oral surgeons and clinicians who are hospital-based. They’re very interested in the latest book, but the truth is, 90% of the information in the book pertains to “practitioners on the front lines” who want answers to questions like: Should I premedicate a patient who needs a sinus lift for a complicated implant, and if yes, what do I do after the procedure? Do I follow up with an antibiotic, and if so, which one and for how long?

“That’s the kind of information they want daily,” Dr. Fang said, “and there is no clear source they can get that information from. There is no dental textbook talking about that, but it has dental implications.”

The Medical Guide for Dentists Treating Complex Patients is going to have a “significant impact on management of all patients,” Dr. Fang said. Patients are living longer and maintaining their dentition longer. Older patients want healthy, beautiful smiles, but if you’re going to reconstruct smiles for patients who are 75 or older, they’re going to come with their share of medical issues and likely a long list of medications.

Managing some of these patients is very complicated, Dr. Fang said, but think of it like peeling back an onion. If you carefully peel one layer after another, everything makes sense. You can deal with the simplest diabetic patient who’s only taking one drug, and a diabetic of a similar age who’s taking five. You just need to understand the difference between those two patients and how their medications impact dental treatment.

As dental technologies advance, you’re completing more complicated, longer procedures, making it even more crucial to understand patient’ medical conditions and their dental implications. With The Medical Guide for Dentists Treating Complex Patients, you have an updated resource that outlines everything you need to know to stay within the guidelines and, most importantly, keep your patients safe.

“One size does not fit all anymore,” Dr. Fang said. “You must be aware of medical issues when patients are spending hours in the chair. My new book represents the cleanest, most up-to-date and precise information and recommendations that are out there.”

Ready to add “The Medical Guide for Dentists Treating Complex Patients” to your bookshelf? Click here to order.