I frequently get asked about 'puffs' (defined as a small amount of sealer that has extruded through the apex in to the periapex).
There appears to be no consensus.
Some people believe in them.
So in an effort to clarify the subject, I present the following.
Choose your Paradigm
It's a matter of advantages and disadvantages. i.e. choosing your paradigm.
Advantages of puffing:
It's the only way in a clinical situation to know, reasonable well, that the apex is sealed. We don't have the advantage of doing a frozen section of the apex to look at it.
Disadvantages of puffing:
Occasionally, if the cement is mixed thin, the excess eugenol or whatever, might cause more post op pain than if you didn't puff.
Advantages of Non-puffing:
It's certainly easier.
Usually the last one millimeter of a canal is the most difficult to negotiate.
It often does off at a 90 degree angle from the rest of the canal. (There are a few tricks for probing it but that would be off the subject here.)
And if you intentionally stay away from the apex, it is unlikely that you will push a file past the apex and damage bone.
Correspondingly it is impossible to overfill if you leave the apex plugged. (Unless of course you put so much pressure on it that you blow the plug out the apex.)
Disadvantages of Non-puffing:
If you don't go to the apex, whatever was in there to begin with is there after you fill.
Unless you kill the little buggers with bleach, that debris consists of necrotic debris, microbes and dentin mud.
If the cement APPEARS to be 1mm short it MIGHT be 3-4mm short depending on the angle of the film.
You cannot tell how much debris there is from a post op radiograph.
This debris itself can be irritating postoperatively.
I categorize overfills into four groups:
Group I may or may not cause inflammation, pressure, or pain depending on the degree to which it irritates the PDL.
Correspondingly, if it does not cause inflammation, it may never absorb either.
Group II will almost never cause post op pain because there is plenty of room for any expansion or pressure.
Furthermore the apex is already in a chronic inflammatory state and doesn't need to create an inflammatory response because the end point of the inflammatory response is macrophages which are already there.
The body being an efficient system sees no reason to create any more inflammation and the macrophages simply have a change of diet...from microbes to cement.
Group III is much the same and will usually absorb uneventfully unless the overfill is so great that it reaches the boundary of the cavity in the bone.
And then it will absorb...but eventfully.
Group IV is the problem. The question is: How can you have a large overfill in a vital apex?
Answer. You either crush bone with your filling or you drill a hole to make room for it by your filing efforts.
Either of these two scenarios are going to cause a lot of inflammation, and pressure on already traumatized tissues.