Why does MTA (Mineral Trioxide Aggregate) require moisture to set, won't this be more dangerous as it gives bacteria sealed in the tooth to flourish?

Doctor's Answers 1

MTA (Mineral Trioxide Aggregate) requires moisture to set because that is part of the chemistry of its setting reaction. MTA is derived originally from Portland cement.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5573456/

However, this does not mean that the root canal should be soaking wet
before MTA is placed.

MTA is used in situations where there is inevitably moisture (blood or tissue fluid) within a part of the tooth or root canal.
For example:
1. Sealing perforations
2. Sealing open root apices
3. Apexification of immature primary teeth
4. Dressing pulp stump wounds after a pulpotomy

In these situations, moisture contamination means that conventional root canal sealers will eventually wash out. MTA is able to set in the presence of moisture and is very biocompatible. This means that cementum and bone can grow onto the exposed MTA surface. This is especially important for healing of teeth with perforations or open root apices.

Since the root canal system itself still has to be thoroughly dried before MTA is placed, there is not enough moisture left behind for bacteria to proliferate. As the MTA sets, it crystallizes and water is needed for this process to occur.

In any case, root canal treatment does not completely sterilize (completely *remove* ALL viable microbes) the root canal system because bacteria are found within the dentinal walls and within complex anatomy (isthmuses and anastomoses) that cannot be directly instrumented. The aim of root canal treatment is to disinfect (*reduce* the amount of viable microbes) within the root canal system to a level where there are no symptoms and healing can occur.

Similar Questions

Why do dentists give differing views on whether I need to extract my wisdom teeth, and does it mean that one of them is wrong?

Singapore does not have national guidelines that dentists must follow when making a decision to remove wisdom teeth. Dentists make clinical recommendations based on their judgment, which is affected by: Experience Recent (the last 6-10) cases that they have encountered Previous adverse outcomes: they may have seen a patient with a severe infection or decay caused by a wisdom tooth that should have been removed earlier to prevent these issues. Training: different dental schools have different philosophies when it comes to indications for removing wisdom teeth.

Photo of Dr Jaclyn Toh

Answered By

Dr Jaclyn Toh

Dentist

Can I still wear retainers or undergo braces treatment soon after a gingivectomy/crown lengthening surgery?

Hi, Yes you can most certainly wear retainers after a crown lengthening surgery, as long as the retainer does not impinge on the affected gums and area. Your orthodontist will be able to adjust your retainers easily for you. On the other hand, it would be advisable to wait for at least 6-8 weeks after any gum surgery, before moving the teeth with braces. In general, we prefer to move the teeth first before performing gingivectomy or other such procedures, especially for the front teeth.

Photo of Dr Geraldine Lee

Answered By

Dr Geraldine Lee

Orthodontist

Ask any health question for free

I’m not so sure about a procedure...

Ask Icon Ask a Question

Join Human

Sign up now for a free Human account to get answers from specialists in Singapore.

Sign Up

Get The Pill

Be healthier with our Bite-sized health news straight in your inbox