Dentaltown November 2019 - 85

Dentists who are using nonbioceramic
sealers and performing single-cone obturation
are asking the sealer to not only hermetically
seal the apex and all portals of exit but also
act as a filler where the gutta-percha cone
does not reach. Many of these single-cone
obturation cases are successful by virtue of
cleaning and shaping-removing the diseased
pulp tissue and microbes and sealing the
cleaned system.
The problem with this approach is that
it's a gamble: It may seal, it may not. Take,
for instance, a case where the gutta-percha
cone slips down the canal and stops 2mm
short of working length. The last 2mm of
the canal is devoid of any filler except the
nonbioceramic sealer. The sealer is now
"asked" to not just seal the apical foramen
from the periapical tissues but also act as a
2mm space filler. Nonbioceramic sealer is
not meant for this type of obturation; it was
designed only to form a thin layer between
the gutta-percha cone and the canal foramen,
not as a 2mm space filler.

Solubility and sealants
That being said regarding nonbioceramic
sealers, some bioceramic sealers may have
an internal problem: solubility. Solubility
refers to the loss of material mass when a
sealer is immersed in water over a certain
amount of time, usually evaluated at 1 day,
1 week, 2 weeks and 3-4 weeks.3 Endodontic
specifications state that root canal sealers
should present solubility of less than 3%.4,5
Studies show that some bioceramic sealers
can have a solubility index of upward of
10%, while traditional resin sealers such
as AH-Plus from Dentsply DeTrey have
a solubility index of only 0.03%.6,7 What
does this mean? Some bioceramic sealers
are more soluble and possibly could degrade
in the presence of tissue or periradicular
fluid or wetness.
Interestingly, it is recommended to
maintain some moisture in the canals to

provide a vehicle for bioceramic sealers to
set. The question I often hear is, "How much
moisture?" An article by Nagas et al. shows
that iRootSP, which is comparable to BC
Sealer, showed the highest bond strength
when compared with AH-Plus, MTA
Fillapex and Epiphany in canals dry with
paper points and ethanol, paper-point dry,
moist and completely wet. Also, iRoot SP
showed similar push-out bond strengths in
very dry, paper-point dry and moist canals.8
The author stated, "The experimental levels
of moisture from dry to wet had differential
effects on the tested sealers, suggesting that
it may be advantageous to leave the canals
slightly moist before fi lling procedures."8
Another study states that bioceramic sealer
sets when it comes into contact with moisture
inside the root canal system.9

Part II:
Mastering
warm vertical
obturation
In the second installment
of his series, Dr. Reid Pullen
will share the tips, tricks and
technique that lead to what
he believes is the best seal,
set and success for root canal
treatment. His article will
appear in the December 2019
issue of Dentaltown.

Testing out a new technique
As an endodontist in private practice
for the past 13 years, I've treated well over
10,000 cases. Initially, I used Kerr's Pulp
Canal Sealer EWT (extended working time)
because that's what we decided in residency
to use after reviewing the past and current
literature on sealers. (To be fair, BC Sealer
and BioRoot were not yet in the mainstream.)
From 2004 to 2012, I used only that product
and the warm vertical obturation technique.
During that period, I was becoming a better
endodontist, learning from my mistakes
and my successes.
In 2012, I started experimenting with
single-cone obturation, mainly because if
you could achieve predictable success with
this technique, it would save hours and hours
of obturation time. After incorporating
laser disinfection in my office using the
photon-induced photo acoustic streaming
technique, or PIPS, using a Fotona laser,
I tried the single-cone technique using a
hydrophilic resin sealer. I saw a pattern of
increased postoperative "checks"-continued
discomfort three months and longer after
dentaltown.com \\ NOVEMBER 2019

85
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Dentaltown November 2019

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