Q: Is EndoREZ canal sealer re-treatable?
A: EndoREZ canal sealer is re-treatable. It sets harder than ZOE—more like a hard ZOE (e.g., ZOE B&T)—but not as
hard as other resin fillers or restoratives. Begin by making a channel with gates-glidden drills following the gutta
percha. Remove the remaining EndoREZ canal sealer with files. There is no chemical solvent for EndoREZ canal sealer.
Q: Can EndoREZ canal sealer be used by itself? With other obturating techniques?
A: EndoREZ canal sealer is FDA accepted as a filler as well as a sealer. So, while it can be used alone, we recommend
using at least a single cone. This gives an apical plug as well as a guide for post preparation. It may also be used
with other filling techniques as a sealer in place of whatever sealer you are currently using. Its hydrophilic
nature, biocompatibility, radiopacity, and superior flow characteristics will only enhance the seal of any system it
is used with.
Q: What if EndoREZ canal sealer is expressed out a portal of exit (“puff” out of apex or accessory
canal)?
A: EndoREZ canal sealer is biocompatible, so it will not cause the irritation associated with nonbiocompatible
materials. As with most sealers, it will eventually resorb. Its radiopacity makes it easier to “track” until it
resorbs.
Q: Can a tetrachloroethylene softening solution solution such as Endosolv be used to remove residual EndoREZ
canal sealer?
A: No, softening solutions will not dissolve EndoREZ canal sealer.
Q: How do I perform a post prep on the same visit when the canal is obturated with EndoREZ canal
sealer?
A: EndoREZ canal sealer takes 30–45 minutes to set up in the mouth and up to an hour to set hard. It does, however,
have high oxygen inhibition. This means that it will set more slowly when exposed to air.
In order to do a post prep the same visit, apply Ultradent’s DeOx™ oxygen barrier solution to the exposed EndoREZ canal sealer, remove the
rubber dam, and have the patient bite on a cotton roll. Check the fill every 15 minutes with an explorer. When the
material tests hard, the post prep may proceed.
Begin the post channel with gates-glidden drills, using the single gutta percha as a guide. Use post drills to
enlarge the post prep as usual.
Q: The instructions describe the use of EndoREZ canal sealer in cases with normal apical anatomy. Can EndoREZ
canal sealer be used in teeth with funnel shaped or open apices? If it is possible, what are the necessary
modifications to the technique?
A: Should you encounter a large open apex, EndoREZ canal sealer can be used for obturation in the following manner:
Fit a cone of gutta percha into the canal for tug back, then apply a small amount of EndoREZ canal sealer to the
apical portion of the canal. Insert the gutta percha. Now mix the EndoREZ canal sealer and deliver it into the canal
through a NaviTip tip that is slipped alongside
the gutta percha in the canal. Fill the canal as usual from the bottom up to avoid entrapment of air.
Q: EndoREZ canal sealer sets moderately hard inside the canal. Is there any solvent that can soften the set
resin in the canal?
A: EndoREZ canal sealer is easily removed using a gates-glidden drill or ProTaper endo removal files to gain access,
followed by regular files. There are no solvents to dissolve it should a re-treatment be necessary.
Q: How do the sealing ability and shrinkage rate of EndoREZ canal sealer compare to those of gutta
percha?
A: EndoREZ can sealer performs favorably. If using hot gutta percha, it is important to remember that gutta percha
shrinks about 6–7% as it cools. Even with cold gutta percha and “lateral condensation,” there are numerous gaps,
since it has historically been used with hydrophobic sealing materials.
To reduce or prevent gaps in the middle third with wide canal spaces, we recommend inserting additional gutta percha
but not to condense laterally.
Q: If resins shrink upon polymerization, how can a resin-based obturation material seal effectively?
A: Remember that all resin materials should not be lumped together into one category. Why? All resin-based sealers
prior to EndoREZ canal sealer were/are hydrophobic. The hydrophilic property of EndoREZ canal sealer contributes a
very important difference. A number of studies now show good sealing with EndoREZ canal sealer, and even 1200µm into
dentinal tubules.
When using EndoREZ canal sealer, researchers have seen unsurpassed adaptation and seal in the apical region and no
shrinkage was observed there. Why? With gutta percha fit with tug-back, the dimensions of resin in the apical
portion are minimal. Using the NaviTip tip to deliver EndoREZ canal sealer to the apex adds significantly to the
predictability of this apical seal.
Even up in the broader sections of the canal in the middle third, shrinkage gaps are minimal and less than what would
be seen with lateral condensation with gutta percha. Since the tubules are filled to 1200µm, even adjacent to such a
gap, bacteria in the tubules are entombed in the set resin and the apical portion is sealed.
Having hydrophilic properties is a step forward for sealing potential for a few reasons:
- The capability to infiltrate and seal dentin tubules that have been treated with EDTA (of File Eze or any other)
and sodium hypochlorite.
- The low contact angle at which a hydrophilic material approaches even moist dentin. This improves the capability
to adapt into tiny irregularities and even into accessory canals.
Q: After cleaning and disinfecting, the root canal still contains a smear layer. How is it possible that the
EndoREZ canal sealer penetrates the tubules?
A: Cleaning with EDTA (File-Eze™ EDTA lubricant) followed by disinfecting with sodium hypochlorite, (ChlorCid™ sodium
hypochlorite solution) not only removes all the smear, but also much or all of the decalcified collagen. EDTA can be
used as a conditioning agent for dentin bonding. It doesn't function in the acid sense, but chelated as a base.
Sodium hypochlorite removes the decalcified collagen making an even better surface for hydrophilic resin adhesion
and sealing. Such is not used for restorative dentistry because it takes many minutes to be effective and it could
be damaging to surrounding soft tissues.
