Proper Preparation for Cement Fills

Proper Preparation a Must

No matter what method you use to fill a canal, it is extremely important that you understand the requirements for preparation FOR THAT METHOD.

For example, if you intend to fill with warm gutta percha it is critical that you have an evenly tapered, round canal that you can get your condensers into.

Because if a round condenser is used in an ovoid or ribbon shaped canal all you succeed in doing is punching holes in the gp.

The condenser must fit closely

enough that the molten gutta percha cannot escape around the condenser.

Otherwise, the pressure needed to move the softened gp apically cannot be attained.

It is also extremely important that whatever size condenser is used, the prep must be able to accommodate this loosely to within one or two mm from the most apical area you intend to condense into.

Thus if you want to condense gp at the apex, your prep must be large enough to accommodate the condenser within 2mm of the apex.

With lateral condensation

the requirements are similar but not as rigorous since very little apical pressure is needed.

A master gp cone is inserted and then lateral pressure is applied to successive points as the canal is back filled.

The only major requirement is that there be no point in the canal where the diameter of the canal is smaller than the diameter of the condenser, as this could very well split a root.

With injectable molten gp the prep must be large enough to accept the needle to within 2mm of the apex because after the gp is injected it still must be condensed vertically as in warm gp method.

There is a further requirement that the

canal must be at least size 50

at the depth you intend to reach with the needle, because the smallest needle through which molten gp will flow is 25 gauge, which has an O.D. of about 0.49mm.

With cement syringe filling...

the smallest needle, indeed the standard needle, is 30ga which has an O.D. of 0.29mm.

Thus the prep at the injection point must be at least 0.30mm to avoid pressure filling.

Other than this, the requirements are the same as gp.