09/26/2026
Root canals, inflammation, and overall health: what does the evidence actually say?
You may have heard claims that every root canal treated tooth remains infected, releases harmful toxins, or causes cancer or heart disease. Current evidence does not establish these sweeping claims.
Root canal treatment aims to remove infected or inflamed tissue, disinfect the canal system, and preserve the tooth. Studies show that many treated teeth heal successfully. However, treatment cannot guarantee complete microscopic sterility or lifelong success. Persistent or recurrent infection can occur and deserves evaluation and appropriate care. [1–5]
The connection between oral health and overall health is real and worth studying. Periodontal disease and apical periodontitis (inflammation around a tooth’s root tip) have been associated with cardiovascular disease. Researchers are investigating inflammation, bacterial dissemination, and shared risk factors as possible explanations. These findings do not establish that root canal treatment itself causes heart disease. [7–9]
Similarly, finding oral bacterial DNA in a coronary blood clot does not, by itself, identify a particular tooth as the source or prove that a dental condition caused the heart attack. [8]
Claims that root canal treatment causes cancer are not established by current evidence. One frequently cited study found fewer previous endodontic treatments among patients with head and neck cancer than among controls. That does not prove that root canals prevent cancer, either. [6]
Treating oral disease matters for preserving teeth, comfort, and function. Whether periodontal treatment also prevents heart attacks or strokes remains uncertain; improvements in inflammatory markers are not the same as demonstrated reductions in those events. [10]
My takeaway as a dentist: take dental infections seriously, assess treated teeth individually, and distinguish promising research from proven conclusions. We can recognize the importance of oral health without overstating what the science shows.
References:
1. Burns LE, et al. Outcomes of primary root canal therapy: An updated systematic review of longitudinal clinical studies published between 2003 and 2020. International Endodontic Journal. 2022.
https://pubmed.ncbi.nlm.nih.gov/35334111/
2. Ng Y-L, et al. Outcome of primary root canal treatment: systematic review of the literature—Part 2. Influence of clinical factors. International Endodontic Journal. 2008.
https://pubmed.ncbi.nlm.nih.gov/17931388/
3. Nair PNR. On the causes of persistent apical periodontitis: a review. International Endodontic Journal. 2006.
https://pubmed.ncbi.nlm.nih.gov/16584489/
4. Siqueira JF Jr, et al. Causes and management of post-treatment apical periodontitis. British Dental Journal. 2014.
https://pubmed.ncbi.nlm.nih.gov/24651336/
5. Duncan HF, et al. Treatment of pulpal and apical disease: The European Society of Endodontology (ESE) S3-level clinical practice guideline. International Endodontic Journal. 2023.
https://pubmed.ncbi.nlm.nih.gov/37772327/
6. Tezal M, et al. Dental caries and head and neck cancers. JAMA Otolaryngology–Head & Neck Surgery. 2013.
https://pubmed.ncbi.nlm.nih.gov/24030728/
7. Berlin-Broner Y, Febbraio M, Levin L. Association between apical periodontitis and cardiovascular diseases: a systematic review of the literature. International Endodontic Journal. 2017.
https://pubmed.ncbi.nlm.nih.gov/27770442/
8. Pessi T, et al. Bacterial signatures in thrombus aspirates of patients with myocardial infarction. Circulation. 2013.
https://pubmed.ncbi.nlm.nih.gov/23418311/
9. Tran AH, et al. Periodontal Disease and Atherosclerotic Cardiovascular Disease: A Scientific Statement From the American Heart Association. Circulation. 2026; published online 2025.
https://pubmed.ncbi.nlm.nih.gov/41399933/
10. Ye Z, et al. Periodontal therapy for primary or secondary prevention of cardiovascular disease in people with periodontitis. Cochrane Database of Systematic Reviews. 2022.
https://pubmed.ncbi.nlm.nih.gov/36194420/
