CEREC doctors.com - Q1 2017 - page 8

6 | CERECDOCTORS.COM | QUARTER 1 | 2017
| | | V O L L M A N N
time. The firing program for Celtra is different and very specific
to the material itself, and actually takes less time. To help ensure
usage of the correct firing schedule for Celtra, a Dentsply Sirona
CEREC Consumables representative will come to the dentist’s
office and program the oven for the dentist, as well as review the
firing process and answer any questions they may have.
WHEN A DENTIST FINDS A MATERIAL THEY LOVE AND BECOME FAMILIAR
WITH, THEY TEND TO BE EXTREMELY LOYAL TO THAT MATERIAL AND
IT’S DIFFICULT TO CONVINCE THEM TO SWITCH. WHAT WOULD YOU SAY
TO A DENTIST WHO IS LOYAL TO ANOTHER BLOCK TO HELP PERSUADE
THEM TO TRY CELTRA DUO (ZLS)?
Two words: Try it. Sounds simplistic, I know, however there’s no
better way to realize the potential of Celtra Duo until it’s actually
tried on a real case.
ARE THERE ANY FUTURE ITERATIONS OR IMPROVEMENTS OF CELTRA
THAT YOU ARE AT LIBERTY TO DISCUSS? SUCH AS LARGER BLOCK SIZES
FOR BRIDGES, ADDITIONAL SHADES, OR EVEN DIFFERENT FORMULATIONS
OF THE MATERIAL THAT WILL HAVE POSITIVE IMPACT ON THE OUTCOME
OF THE FINAL RESTORATION?
Yes, there are larger size blocks in the works, and we already
have a comprehensive array of shades. As far as different material
compositions, Dentsply Sirona is known for innovation in technol-
ogies and material science, so expect more great things as a matter
of course from us in the future.
LET’S SAY YOU’VE JUST HANDED A CEREC DOCTOR A BOX OF CELTRA DUO
(ZLS) BLOCKS TO START USING RIGHT AWAY. WHAT WORDS OF ADVICE YOU
WOULD TELL THAT DOCTOR TO HELP ENSURE A SUCCESSFUL EXPERIENCE
AND RESTORATIVE OUTCOME WITH THE MATERIAL?
I’d tell them to simply follow the Celtra Duo (ZLS) processing
guidelines. They’ll find that using Celtra is quite easy and offers a
simplified, streamlined workflow from start to finish; follow the
guidelines, makes sure to use the Celtra firing schedule, and they’ll
have a successful outcome. Another beneficial thing to note is that
Celtra restorations do not require structural support during firing,
so there’s no need to use firing pins or putty. Simply place the resto-
rations on a firing pad on top of the honeycomb and begin firing.
MATERIAL STRENGTH IS ALWAYS A PRIMARY FOCUS OF ANY NEW MATERIAL,
AND IT’S ALSO AN AREA THAT’S ALWAYS UP FOR DEBATE AND ALWAYS
UNDER THE MOST SCRUTINY; THERE ARE FRACTURE TOUGHNESS,
FRACTURE RESISTANCE, MODULUS OF ELASTICITY, VICKERS HARDNESS,
ETC. WHICH OF THESE MEASUREMENTS SHOULD MATTER MOST TO
DENTISTS, AND WHY? IS THERE A VALUE FOR EACH THAT, ONCE REACHED,
IT REALLY DOESN’T MATTER TO GO HIGHER?
It seems in dentistry that fracture resistance, fracture toughness,
flexural strength, and modulus of elasticity are used interchange-
ably. All of them in essence refer to the amount of force, or load,
thematerial is subject to before cracking. Once a fracture toughness
value near to or duplicating that of natural dentin is reached for any
material, it is of sufficient strength towithstand forces in the in-vivo
oral environment. As mentioned earlier, Celtra Duo has an average
KIC value of 2.65, which is closest to that of natural dentin (3.0 KIC )
among all materials tested. One test we put Celtra Duo through
that’s worthwhile to note is the anterior crown fracture test. This is
a rigorous test designed to determine load an anterior crown can be
subjected to before fracturing occurs. All crowns were tested before
artificial aging, and again after artificial aging, which consisted of
6,000 thermal cycles (41°F/131°F) and 1.2 million chewing cycles.
An unexpected, yet welcome result of this test was the fact that after
artificial aging, Celtra Duo retained its high strength, whereas the
other materials tested lost considerable strength after aging.
It’s important to note that there are different testing methods
and each will result in different values. For example, a material
tested using a biaxial testing protocol will result in higher strength
values than if the samematerial was tested using themore rigorous
and demanding 3-point bending test. For materials such as
ceramic, the biaxial strength will be significantly higher than the
value derived by 3-point bending tests. Case in point: the 370 MPa
flexural strength of Celtra Duo (ZLS) was obtained using the more
demanding 3-point bending test, yet when we measure Celtra Duo
(ZLS) using the biaxial test, we obtained values significantly above
500MPa. So it’s important to take the testing method into account
when comparing strength values of different materials.
What’s also important to consider when choosing a material
is edge stability. Edge stability is the resistance to chipping at
the margins. Celtra Duo crowns milled with knife-edge margins
demonstrate excellent edge stability and no chipping compared
to other zirconia-based and non-zirconia-based materials tested.
WHAT SPECIFIC AREAS OF MATERIAL TECHNOLOGY, RESEARCH, AND
DEVELOPMENT DO YOU SEE MATERIAL MANUFACTURERS FOCUSING ON
MOVING FORWARD IN THE MONTHS AND YEARS AHEAD, AND WHAT ARE THE
DRIVING FORCES BEHIND THIS FUTURE DEVELOPMENT?
As with any successful technology, innovation is inevitable and
welcome, as it leads to the creation of materials with enhanced
working properties, expanded indications, and improved results.
For Dentsply Sirona, the dental professionals who use our prod-
ucts are the primary driving force for improvements. We listen to
what dentists want, and our goal is to deliver what they are asking
for. Material science and technology is continuously improving,
and therefore so will the materials being developed. As the dental
solutions company, Dentsply Sirona aims to provide compre-
hensive systems and solutions designed to optimize and simplify
workflow. So there’s this synergistic, complementary relationship
that all of our products are designed to work together as a unified
solution. We take this total solution-oriented approach into
account while developing anything new, whether they are CAD/
CAM hardware, software, materials and other consumables.