Do I really need antibiotics before EVERY dentist visit now that I have a knee replacement? My dentist and my surgeon are saying different things

I had my left knee done last September and it has gone well, so this is not a complaint, more a confusion.

I have my regular cleaning coming up and when I called to confirm the office asked if I was taking an antibiotic beforehand because of my joint replacement. I said nobody told me to. The hygienist sounded surprised and said a lot of their replacement patients take one pill an hour before they come in. So of course now I am worried.

Here is the part that is making me crazy. I asked my knee surgeon's office and the nurse said they do not routinely have people premedicate for dental cleanings anymore and that it was mostly an older practice. So my DENTIST wants me to and my SURGEON does not. Who do I listen to? I do not want to be the one person who skips a pill and ends up with an infection in a brand new knee, that is my nightmare. But I also do not love taking antibiotics for no reason.

Has anyone else been caught in the middle like this?

You are not the only one, I went round and round on this exact thing.

When I had mine done the surgeon told me to premedicate before dental work for two years and then stop. So that is what I did, two years to the month, then quit. But my sister in law had hers done by a different surgeon a few years later and was told she never needed it at all. Same operation, same city, totally opposite instructions. It really does seem to depend on who did your knee and how long ago you trained, if that makes sense.

Is the two year thing still a rule or is that outdated now? That is what I could never get a straight answer on.

I was always told once you have a replacement you premedicate before ANY dental work for the rest of your life, no expiration. That is what the card in my wallet says and I have never questioned it.

I will admit I am a little nervous reading this thread because I also have type 2 diabetes and I have always assumed that put me in the take no chances group. Now I am wondering if I have been taking a pill for years that I did not need, or if I am actually one of the people who genuinely should. I hope Dr. Ellsworth weighs in because I clearly do not understand the rules as well as I thought I did.

Quick one to add to the pile: does it matter WHAT the dentist is doing? A regular cleaning feels different to me than a pulled tooth or a deep cleaning under the gum. My checkup is just a polish and I cannot see how that reaches my knee.

Let me give you the short version first, then the reasons, because this is one of the most common questions I get and the honest answer has genuinely changed over the years.

For most people with a knee replacement, routine antibiotics before every dental visit are no longer recommended. The current framework, from the 2015 American Dental Association clinical practice guideline and the appropriate use criteria the orthopaedic and dental groups worked out together, does not support giving a preventive antibiotic to the average, otherwise healthy joint replacement patient before routine dental care. It moved away from a blanket rule and toward a case by case decision. So the surgeon's nurse who told Joan they do not routinely premedicate is reflecting where the guidance actually sits now, and the "for life, no exceptions" card many of you are carrying reflects where it sat a decade or two ago. Neither office is being careless; they are standing in different years of the same conversation.

Now the reasons, because "it depends" is only useful if you know what it depends on.

The worry behind all of this is a prosthetic joint infection, an infection that settles on the implant itself. Over the whole life of a knee replacement that runs somewhere in the range of 1 to 2 percent, and it is a serious event when it happens, which is why the instinct to prevent it is a good one. The specific fear with dentistry is hematogenous seeding, the idea that bacteria stirred up in the mouth travel through the bloodstream and land on the joint. That can happen in theory. What changed the guidance is that when researchers actually went looking, the case control studies did not find that dental procedures were meaningfully linked to joint infections, and everyday things like chewing and brushing put bacteria into the bloodstream far more often than a twice yearly cleaning does. Against a very small possible benefit you have to weigh real downsides: allergic reactions, antibiotic resistance, and gut effects like C. difficile.

To Carol's question, the "two years and then stop" instruction was a widely used rule of thumb, not a hard biological cutoff. The first months after surgery are when clinicians are most cautious, but the two year number was always more convention than proven line in the sand, and it is one of the things the newer guidance stepped back from.

To Bev's point, the type of procedure genuinely does matter. A polish and checkup are very low on the bleeding scale. Procedures that involve real manipulation of the gums or the tissue around the tooth, or an extraction, are the ones that come up in any discussion of premedication at all. A routine cleaning is not usually in that conversation.

And Sue, your instinct about being in a different group is the right instinct, it is just that diabetes alone is not automatically the deciding factor. The people for whom clinicians are more likely to still consider an antibiotic are those with reasons their body handles infection poorly: an immune system suppressed by disease or medication, poorly controlled diabetes rather than well controlled, a history of a previous infection in the joint, or certain inflammatory conditions. If you sit in one of those groups the math tips, and that is exactly the situation the guideline leaves open to judgment rather than settling for everyone.

So here is the one thing I will not do, which is tell any of you individually to take a pill or skip it. That decision belongs to a conversation between your own dentist and your own surgeon, ideally the two of them agreeing, with your specific health in front of them. If they disagree, ask each of them to tell you their reason, not just their instruction, and you will usually find the disagreement dissolves once you know whether it is about your risk profile or just about which year they learned the rule. For the wider picture of what a replaced knee is and is not vulnerable to, our piece on caring for your new knee for the long term covers infection signs worth knowing, and the honest numbers on complications are laid out in knee replacement risks for women.

Coming back to close the loop in case it helps someone.

I did exactly what Dr. Ellsworth said and asked both offices for their reason, not just their answer. My surgeon's office confirmed they do not have me premedicate for a routine cleaning given my history, no diabetes, no immune issues, joint doing fine. The dental office said they simply default to asking because so many patients were told to years ago, and they were completely fine following my surgeon's guidance once I brought it back to them. So it was never really a fight between them, it was two habits from two different eras, exactly like this thread said.

Went in last week, had the cleaning, no pill, no drama. Thank you all, I feel like I understand my own knee a little better now instead of just being scared of it.