In short: A single-sitting root canal completes the whole treatment in one appointment, while a multiple-sitting one is done over two or more visits with a medicated dressing placed inside the tooth in between. Single-sitting is quicker and convenient, but it depends on the case — it suits teeth without heavy infection and with straightforward canals, and it isn’t always possible.
Both approaches do the same core job — removing the infected or damaged nerve, cleaning and shaping the canals, and sealing the tooth — but they differ in how the treatment is spread out.
Single-sitting root canal. The entire treatment is completed in one appointment, from cleaning to sealing the canals. Its advantages are convenience (fewer visits), no long period with a temporary filling, and getting it all over with in one go.
Multiple-sitting root canal. The treatment is carried out over two or more visits. Between appointments, the dentist places an antibacterial medicated dressing (such as calcium hydroxide) inside the tooth and seals it temporarily, giving the infection time to settle before the tooth is finally filled.
When done on the right tooth, both have similarly high success rates — so it’s not that one is simply “better.” What matters is choosing the right approach for your tooth.
Why single-sitting isn’t always possible. It’s best suited to teeth with limited or no active infection, straightforward canal anatomy, and no ongoing discharge. A dentist may recommend multiple sittings when there is:
- Significant infection or an abscess with pus or discharge that won’t dry up in one visit.
- Difficult, curved or calcified canals, or retreatment of a previously failed root canal.
- A flare-up of pain or swelling, or a tooth that needs settling before sealing.
- Practical factors like the time available or how long you can comfortably keep your mouth open.
Trying to force a heavily infected tooth into a single visit can lower success and risk a painful flare-up — which is exactly why case selection matters.
Your dentist will assess the tooth and advise which approach is safest. Book a root canal treatment and we’ll recommend the right plan for you.