Once you have seen the future, it is difficult to go back. For so many clinicians
who have placed metal-free crowns and bridges, it is unbearable to go back
to PFM bridges even in demanding situations. While multiple-pontic spans
still require a metal framework, long bridges with 1 or 2 pontics between
abutments show considerable promise when they are fabricated using the innovative
technique known as the LVI Bridge.
Fiber reinforced technology is being used in various industries (e.g. aeronautical
and shipbuilding industries). The material is used in situations where permanent
loads and cycled loads are applied and light weight is required.
The LVI bridge was conceived at The Las Vegas Institute for Advanced Dental
Studies. It is an Empress bridge that is packed with Vectris for strength.
There are many other metal free restorative options available today, Belleglass,
Cristobal, Sinfony, Cercon, LAVA, but none of these compare aesthetically
with an LVI bridge.
Admittedly there is no way to scientifically prove the strength of the LVI
bridge for a few reasons. Ivoclar does not advocate Empress 1 being used
in this manner either with Vectris or without, and each bridge is different.
We do know Vectris is extremely strong, 1300MPa so when done correctly these
bridges are likely to be effective as a definitive restoration.
The fabrication technique must be followed in exact detail or failure is
assured. It consists of conventional wax-up for Empress to be pressed in
it's normal fashion except it is pressed in multiple units: ie: a 3 unit
bridge 6-8 would be pressed as 2 separate units. #6 would be pressed by itself
and 7 and 8 would be pressed as a separate unit. The linguals and interproximal
connector area is cut out to allow for maximum packing of Vectris fibers.
(The ideal preparation for an LVI bridge would have a 2mm or more lingual
and interproximal shoulder). The more fibers correctly packed into the connectors
and lingual the stronger the bridge. It is noted the co-authors experience
with 598 bridges has shown 5 failures 4 of which were unstable occlusion
patients. We cannot overemphasize how important it is to have a stable neuromuscular
occlusion on these cases.
The Vectris is processed and bonded to the finished Empress in the Vectris
VS1 under vacuum, and light cured. This is ideal for exceptional bonds to
the etched and silinated Empress material at the connectors. This part of
fabrication, of course, is done on a solid model for accuracy and verification
purposes rendering the restoration passive and as adjustment free as possible.
The following examples demonstrate that the LVI bridge is a viable prosthetic
alternative to consider even in extensive restorative cases. It should be
noted that the success of this type of restoration-or any type of restoration-is
highly dependent on ideal neuromuscular and micro occlusion.
Case #1 is a 78 year-old female who had extensive crown and bridge work
completed many years ago. Her chief complaint was that the porcelain facing
on #9 had come off. After careful examination, it was determined that many
of the restorations were failing. One of the prostheses was a bridge from
#6-#14 with pier abutments at #9 and #11. It was also determined from the
patient's impressive bony exostoses that she had a parafunctional habit of
long duration. Full mouth reconstruction was accomplished to ideal neuromuscular
occlusion. Restorations were fabricated from Empress, including LVI bridges
made from Empress reinforced with Vectris. Most notable was the 9 unit LVI
bridge from #6-#14. At 16 months post-op, the case is successful.
Case #2 is another 78 year-old female. Her chief complaint was a failing
#5-#8 bridge. The patient did not want implants nor did she want a removable
partial denture. The abutment at #8 had fractured at the gingiva creating
leverage that damaged the bony support of #5. #5 was extracted and #8 had
root canal therapy. While it was explained to the patient that a bridge of
this span replacing her cuspid was a compromise, the patient elected to proceed.
The 3 pontic span was double abutted at both ends with #3 and #4 supporting
the distal and #8 and #9 supporting the mesial. The prosthesis placed was
an LVI bridge made from Empress reinforced with Vectris. This case was recently
placed and is being monitored closely for success, concerns being the long
pontic span at the cuspid and the lack of establishment of neuromuscular
occlusion.
PFM bridges are no longer the only alternative for extensive crown and bridge
prosthetics. All porcelain materials such as the LVI bridge are showing real
promise in eliminating metal from the practice of dentistry so that dentists
can provide outstanding esthetics in all cases.
Josh Bernstein, DDS is a Clinical Instructor at LVI. He maintains a private
practice in Piedmont, California focusing on restorative cosmetic dentistry,
smile design and outstanding guest services. Bob Clark, CDT, is an LVI affiliated
lab technician who owns Williams Dental Lab in Gilroy, California. His lab
provides extraordinary service to dentists who practice comprehensive neuromuscular
dentistry.
