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Antibiotics After Root Canals

Antibiotics After Root Canals

Do I really need the antibiotics my dentist is giving me?

Phoebe Lapine

Thu, 27 Aug, 09:01

Hi Dr. Miller!

I had a root canal yesterday and my Dr. was insistent on putting me on a short course of antibiotics because of some inflammation/irritation in the area.

I was curious if there was a general litmus test for when antibiotics are necessary and worth the risk to overall gut health, and when it’s ok to skip.

Are there any more localized workarounds to prevent infection if it’s a hard to reach place like the root?

Thanks so much in advance!



Dear Phoebe,

Once again you have opened a can of worms!  Great question!

Why this question really matters

The overuse of antibiotics in healthcare has contributed to two growing problems – antibiotic resistance and the disruption of the human microbiome.  According to Langdon, et al., antibiotic-resistant “superbugs” killed an estimated 50,000 people in Europe and the U.S. in 2015 and are projected to cause 10 million deaths worldwide by 2050.1 When I graduated from medical school (2002) there was very little in our education about the importance of the bacteria, viruses, and yeast in our gut. We now know that disruption (by stress, poor diet, antibiotics, etc…) of the gut microbiota contributes to numerous diseases, including inflammatory bowel disease, asthma, rheumatoid arthritis, diabetes, obesity, and depression.2

How Dentists Contribute to the Problem

The World Health Organization declared earlier this year that  “the world urgently needs to change the way it prescribes and uses antibiotics.”3 And I believe that the fastest way to make this critical shift is by doing what you did Phoebe – get educated and question whether an antibiotic is truly needed when it is handed to you.  It turns out that there are millions of patients in your situation.  Dentists, according to the CDC, write roughly the same number of antibiotic prescriptions each year as pediatricians and nearly twice as many as emergency medicine physicians.4

 I am one of the dentists who use antibiotics in my practice.  Most often it is for the treatment of cellulitis and when removing an infected tooth that has a well-established abscess (down in the bone).  Antibiotics have an important role in certain cases.  When I was doing more root canals, six years ago or so, I would prescribe antibiotics after the initial phase of root canal treatment (removal of the infected pulp).  If I were doing root canals today I would not prescribe antibiotics routinely.  There is a growing body of evidence demonstrating that antibiotic use in dentistry often does more harm than good.  A 2016 article on the AAE (American Association of Endodontists) website had this to say on the subject:

“Antibiotics have limited benefits in dentistry, and their overuse and misuse pose significant risks to our patients.” 5

If that is what the endodontists think of antibiotics (and they are the root canal experts) why are antibiotic prescriptions still standard practice?

  Figure 1

How Patients and Lawyers Contribute to the Problem

Most dentists, endodontists, and oral surgeons I know get tremendous satisfaction out of helping patients.  We are trained to get patients out of pain and help them prevent future disease.  Dentists are overprescribing antibiotics partly out of habit—it is indeed (sigh) hard to make a change.  But many antibiotic prescriptions are being written because patients expect the script and raise an eyebrow when it isn’t offered. 

Another driving force is that dentists don’t want to get sued.  A poor outcome after a root canal often involves a lot of pain.  And when patients hurt they are more likely to collect on a lawsuit.  It’s sad but true.  The case is still being made in courts that antibiotics after a root canal are standard of care – despite the literature I’ve mentioned already.  My hope is that articles like this will help accelerate the implementation of an evidenced-based, new standard of care.  We will know a new standard has arrived when dental schools stop teaching students to write a script every time they do a root canal.  I’m hopeful.

Why Root Canals are Tricky

There are two key objectives when treating infections, and they are both especially difficult to achieve when doing root canals. The first objective is to get rid of the source of infection, be it an abscessed cyst in the skin of your back or an infected tooth in your lower jaw.  The second objective is to thoroughly drain any associated pus – the necrotic pool of slime that harbors aggressive anaerobic bacteria.  The problem with infected teeth is that no one wants to get rid of the source.  The loss of teeth is expensive, unaesthetic, and causes other teeth to shift into a dysfunctional pattern.  Additionally, it is very difficult to drain pus if it is sitting at the bottom of the tooth root, and encased in bone – as most root-canaled teeth first present (see Figure 1).

A root canal is our best attempt, as dentists, to help patients keep their teeth.  But the trade-off can be a low-level lingering infection due to our inability to thoroughly drain the pus.  Endodontists and dentists are therefore justified in wanting to use antibiotics to clean up any residual infection.  It’s akin to a cancer surgeon who tells his patient, “we got all of the tumor out.  The margins are clear. But, we are going to do a round of radiation therapy just to be safe.”

Newer Treatment Options

A growing number of dentists are embracing new root canal techniques and botanical antimicrobials.   If I needed a root canal tomorrow I would go to an experienced endodontist who uses ozone. According to Ajeti, et. al, ozone has brought about a revolution in endodontic practice, because of its superior ability to kill off residual infection left behind in irregularities of root-canaled teeth.6 Using ozone at the end of a root canal treatment kills more bacteria, which means you are much less likely to need a post-treatment antibiotic.   

If I were a root canal patient I would also use an immune-modulating botanical-based antimicrobial instead of a prescription antibiotic (assuming I didn’t have cellulitis or a facial space abscess). There are several out there, but the one I have the most confidence in is Biocidin (BioBotanical Research, Santa Cruz, CA).  I like the Biocidin LSF formulation when I need more aggressive antimicrobial action.  I like the Dentalcidin oral rinse when I’m concerned about keeping the oral microbiome in balance and want to clear up any remaining infection in the gingiva (look below for notes on the use of Biocidin LSF and Dentalcidin). 

Can I Skip the Post-Root Canal Antibiotic?

In your case Phoebe, I would need to see x-rays and do a clinical exam to assess the severity of the infection before giving you my definitive recommendation.  The duration of your symptoms and extent of infection also guide me on whether to prescribe post-op antibiotics or not.  Since I don’t have the luxury of seeing you as a patient I’ve put together a checklist to help guide you and your tribe.

You Should Consider an Alternative to Prescription Antibiotics If….

  • There is minimal bone loss and the abscess around the tooth is small
  • Your root canal was done by an experienced clinician (endodontist)
  • Your root canal treatment included ozone therapy
  • Your dental specialist considered the root canal a success
  • You are as healthy as Phoebe LaPine (and not a diabetic and don’t use steroids)
  • You did not have symptoms of jaw pain; pain with chewing; hot and cold sensitivity; swelling or a bad taste (from pus drainage) in your mouth for more than 3 weeks prior to the root canal
  • You don’t have swollen lymph nodes in your neck
  • You can open your mouth at least 40mm (3 finger widths)
  • The gum tissue around the root-canaled tooth is not swollen
  • The teeth around the root-canaled tooth are healthy
  • You have no facial swelling, cellulitis, or drainage
  • You don’t have a fever

If you can check all of the above boxes then you should talk with your endodontist, dentist, or dental hygienist about skipping the oral antibiotic and trying the Biocidin LSF or Dentalcidin Liquid.   For many people, this discussion is just too complicated.  Which is why more people are bypassing root canals all together and choosing to definitively remove the source of infection by extracting the tooth.  I believe root canals still have a vital role in dentistry.  Just remember, it is your body and you have options.

How I Use Biocidin LSF and Dentalcidin

I put 1-2 pumps in my mouth and swish it around for approximately 15 seconds.  I then hold the product under my tongue for 30 seconds to allow it to absorb through the floor of the mouth.  It’s generally a good idea to spit out either product rather than swallow it.  In cases of a significantly abscessed root-canaled tooth, I prefer the Biocidin LSF.  Remember, we need the antimicrobial to get into the bloodstream to be effective at the apex of the tooth root. Biocidin LSF is better in my opinion at getting into the bloodstream.  For all other dental applications, I choose Dentalcidin.  And I typically will use the products for 5-10 days after a surgical procedure.  Although the herbs used in Biocidin LSF and Dentalcidin are, individually, all thought to be safe for the pregnant patient, there are no human studies on the Biocidin formulation in pregnant women.  The general rule, therefore, is to avoid Biocidin and Dentalcidin if you are expecting.

Add a Probiotic

Whether you decide to follow the standard of care and take one of the commonly prescribed antibiotics after your root canal or you give the Biocidin LSF a try, I recommend that you take a good probiotic—with at least 30 Billion CFU’s—daily during your treatment.  Sacharomyces Boulardii appears to be immune boosting and is probably a good addition to your probiotic during the treatment of your infection.  And remember, any time you choose not to follow the standard of care you are obligated to review your plan with your treating dentist.

Speak Up

Much of the antibiotic prescribing habits of dentists are sadly driven by patient expectations.  You, Phoebe, are not among the millions of Americans who still believe that antibiotics are a panacea.   Let your dentist know that.  You might be pleasantly surprised by his or her response.

All this chatter about misadventures in dentistry has me itching to go brush, floss and waterpik – STAT. 

Until next time, keep smiling.

Dr. M






Adam Miller, DDS, MD
is a dentist, surgeon,
integrative medicine expert,
and husband
who has trekked the globe
looking for the heart of the matter.



1. Langdon A, Crook N, Dantas G. The effects of antibiotics on the microbiome throughout development and alternative approaches for therapeutic modulation. Genome Med. 2016;8(1):39. Published 2016 Apr 13. doi:10.1186/ s13073-016-0294-z

2. Zhang S, Chen DC. Facing a new challenge: the adverse effects of antibiotics on gut microbiota and host immunity. Chin Med J (Engl). 2019;132(10):1135-1138. doi:10.1097/CM9.0000000000000245


4. Antibiotic Use in Outpatient Settings, 2017 /
What Do We Know About Antibiotic Use in Outpatient Settings?

5. Walton, Richard M. “Antibiotics: A Risky Proposition,” ; Posted in Pharmacology, 2016

6. Ajeti NN, Pustina-Krasniqi T, Apostolska S. The Effect of Gaseous Ozone in Infected Root Canal. Open Access Maced J Med Sci. 2018;6(2):389-396. Published 2018 Feb 14. doi:10.3889/oamjms.2018.102

7. Lindeboom JAH, Frenken JWH, Valkenburg P, Van Den Akker HP. The role of preoperative prophylactic antibiotic administration in periapical surgery: a randomized, prospective double- blind placebo-controlled study. Int Endod J 2005;38:877-81.

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