If you need a root canal, the first question most patients ask is: “Can you do it all in one visit?” The answer depends on the tooth, the infection, and the dentist’s judgment. A 2025 systematic review in BMC Oral Health examined the evidence behind a related question — does the number of visits change how much pain you feel afterward?
The short answer: probably not much.
What the researchers set out to answer
Dr. Gunjan Kumar and colleagues searched PubMed, Scopus, Cochrane, DOAJ, and Web of Science for studies measuring postoperative pain after single-visit versus multiple-visit root canal therapy, including randomized trials and prospective studies that used tools like the 1-to-10 pain rating scale.
Their question was practical: after the numbness wears off, does a one-appointment root canal hurt more, less, or the same as one done over two or more appointments?
The main finding: most studies found no difference
Eight of the included studies found no meaningful difference in postoperative pain between single-visit and multiple-visit treatment. Six studies found that pain after the canals were filled was actually less with single-visit treatment.
So if there is any pain advantage, it leans slightly toward the single visit — but the most common result was simply “no difference.” The number of visits does not appear to drive how much pain patients feel afterward. The review noted that studies varied in how they measured pain and in their methods and patient selection, which explains some of the inconsistency.
Why does this debate exist at all?
For decades, the traditional approach split root canals into multiple visits, placing antibacterial medication inside the tooth between appointments — more time with disinfectant meant fewer remaining bacteria.
Single-visit treatment became practical as instruments, irrigating solutions, and rotary tools improved, letting dentists clean and shape canals thoroughly in one session. Patients prefer it: one appointment, one round of anesthesia, less time off work.
The evidence has caught up with the practice. This 2025 review fits the broader trend: when canals are cleaned and sealed well, whether that happens in one visit or two does not change the pain experience much, and healing outcomes are comparable.
When a dentist still recommends multiple visits
Even with reassuring pain research, there are real clinical reasons to split treatment:
- A heavily infected or draining tooth may need a medicated dressing between visits to bring bacteria down before sealing.
- Complex anatomy — curved, narrow, or extra canals — can take longer to clean properly, and splitting a long procedure is kinder to patient and dentist alike.
- Patient comfort. Not everyone can sit comfortably through a longer appointment; two shorter visits may be the better experience.
The number of visits is a clinical decision, not a convenience prize. A dentist recommending two visits for an infected molar is managing risk, not padding the schedule.
When a root canal is not enough
Sometimes a tooth cannot be saved, or a previously treated tooth keeps failing. That is where a prosthodontist’s perspective matters. Dr. Leila Nikpour at Expert Dental Group evaluates the whole picture — the bite, neighboring teeth, and what a replacement would look like if the tooth has to go.
If a tooth can be saved, she will tell you. If an implant would serve you better long term, she will tell you that too — and with in-house 3D CBCT imaging, 2,500+ implants placed, and more than 15 years of dentistry experience, either path starts from a complete 3D picture. One more thing patients forget: a root-canaled tooth needs a proper crown afterward, since it is vulnerable to fracture — which is how many such teeth end up extracted later.
The bottom line
The 2025 Kumar review found that single-visit and multiple-visit root canals produce essentially the same postoperative pain, with a slight edge to single visits in some studies. The one-versus-two decision should rest on your tooth’s condition — infection, anatomy, complexity — not on fear of extra pain.
References
- Kumar G, Jena S, Manila N, Fareed M, Karobari MI. Incidence of postoperative pain after single-visit and multiple-visit root canal therapy: a systematic review. BMC Oral Health. 2025;25(1):47. DOI: https://doi.org/10.1186/s12903-024-05412-1. PubMed: https://pubmed.ncbi.nlm.nih.gov/39780175/
Frequently Asked Questions
Does a one-visit root canal hurt more than a two-visit one?
No. A 2025 systematic review found most studies showed no difference in postoperative pain. Some studies even found slightly less pain after single-visit treatment.
Why would a dentist do a root canal over two visits?
Usually for heavy infection needing a medicated dressing between visits, complex canal anatomy, or patient comfort during long appointments. It’s a clinical decision, not a sign of a problem.
Is single-visit root canal treatment as effective?
The research indicates yes — when canals are cleaned and sealed properly, healing outcomes are comparable whether done in one visit or two.
How much pain should I expect after a root canal?
Most patients have mild to moderate soreness for a few days, manageable with over-the-counter pain relievers. Severe or worsening pain warrants a call to your dentist.
What happens if my root canal tooth keeps hurting or failing?
Repeated failure may mean the tooth can’t be reliably saved. A prosthodontist can evaluate whether retreatment makes sense or an implant would give the better long-term outcome.
Tooth pain or a failing root canal? Call Dr. Leila Nikpour at Expert Dental Group, (916) 888-1646 — 5070 Foothills Blvd, Suite 2, Roseville, CA 95747. Open Mon–Fri 9–6, Sat 9–1.