and welcome to this clinical video today I have an exciting case to share with you a great example of
what I do when a large PSM bridge factors I'll replace it with an obsidian PSM it is a lithium
silicate material known to achieve two times more chip resistance than your traditional PSMs we can
see he has severe crowding of the lower incisors and a unilateral cross bite a closer look reveals
chipped and cracked porcelain inflamed gingiva in a failed +5 composite on the upper right this old
PSM spanned from 7 to 11 with pancakes replacing left central and lateral incisors because number
seven was splinted to the rest of the bridge we can note the interdental gingivitis created by the
bacteria due to the inability of the patient to floss in between the restorations to rehabilitate
this mile I treatment plan for obsidian veneer on number six and obsidian pressed to metal single
crown on seven and an obsidian pressed ml of four unit bridge from eight to eleven as I was cutting
through this restoration with the zoo cut bar I felt that the metal was very thick and had
to switch to a reservoir to be able to get to the material after using a double-ended crown remover
I finally got the bridge off in few pieces you can appreciate the amount of metal thickness there
was on the lingual after the bridge was removed I struggled a great deal to get this off and in the
process I nicked the underlining prep so here I am using acid etch and bonding to prepare the surface
prior to expressing ty core dual cure flowable composite material the damage is corrected and
prep is reshaped to provide more retention and resistance for the future restoration for the
veneer I started the preparation with the use of a calibrated bird that will provide precise
cuts of 0.3 do Diwali point-five middle and point seven millimeter inside early then I
am blending in the cuts using a fine diamond with a 1.5 calibrated bird I am doing here an
incisor reduction this calibrated birds keep the reduction into animal and offer correct thickness
to fabricate a well-designed obsidian veneer I found that with pre calibrated Birds I can
stay into enamel which is essential for effective addition of an obsidian or any of ceramic veneers
due to gingival inflammation still present I opted to temporize and finalize the preps at the next
appointment here taking up the Provisionals one week later the excess cement was removed with
Cavett Ron and Pete were cleaned with pumice tissue was still irritated possibly because in
my provisional I left some over counter margins or I did not provide sufficient interproximal
separation to prevent popular impingement in the end for a predictable impression I
still achieve adequate tissue management with a double core technique first I use double zero
with epi the number two chord as my second code to gain lateral retraction because double chord
displaced the tissue 0.5 millimeter gingival II I was able to drop the margin and with a
fine diamond on a slow-speed with no water I trace around and refine the margins avoiding
contact with the tissue I tried to avoid further traumatizing the soft tissue during finish line
preparation or second chord application Here I am placing a mixture of number 1 and 3 anatomical
camper caps and have the patient's bike down for about 7 minutes while my assistant is finishing
up removing the second chord I start injecting refresher material when doing this many units
I always use a constant rate this will ensure rigidity and uniform display of the impression
material I think this is a good way to capture an accurate impression easy to read that will help
CAD CAM technician to create a well-fitting margin and a better imagine for file I found transferring
the color of the underlining tooth structure with the photo of selected shake in place is a
great way of communicating the shade to the lab technician here is at the delivery appointment
we can appreciate the health of the soft tissue after the temporaries were removed preparation
was freed of cement and cleaned using prophy cup and pumice after trying each restoration
individually to evaluate marginal fit I will try them collectively to evaluate the proximal fit
the facial surface of the veneer prep can also be clean from provisional resin leftovers by using
air abrasion for isolation I use my large strip and cotton rolls and as a looting material for
the veneer I used varial ink 37-percent acid etch was applied to enamel and dentine and allowed to
react for 15 to 20 seconds one step that should not be omitted is a to 1-minute application of
glutaraldehyde agent such as g5 knowing for its antibacterial and desensitization properties
then the entire surface was coated with universal adhesive and scrubbed in for 20 seconds then with
oil moisture free air was used to displace the coat into a thin film after the inner
surface of the veneer was cleaned and salinated varial including composite was applied onto the
intaglio surface and veneer was seated with light pressure using wooden sticks while light pressure
was maintained excess cement was removed with a micro brush and briefly light cured so excess
could be easily removed with hand instruments liquid stripped was applied to create a good
marginal transition without an oxygen inhibiting layer final polymerization was completed and then
liquid stripped was real stuff with water the proximal surfaces should be carefully examined
and if any cement residue is found should be removed to ensure perfect seat for the other
restorations the rest of the preparations are again cleaned with pumice paste and treat it with
g5 before the cementation of the Obsidian press to metal restorations when there is an area where
the gingival tissue is covering the finish line I use the double zero cord to keep the tissue away
from being trapped under the cemented margin or I use it to protect the sulcus from resin
cement infiltration my choice of cement for any metal restoration is rely X looting plus it is a
resin-modified glass ionomer self curing cement that has attack and wave light curing option
making it easy to clean up the excess because I use two different types of looting agents for
this case I opt to cement each restoration individually taking particular care during
cleanup phase to ensure proper sitting after all the leftover cement was removed occlusion
was stressful produces and lateral exclusion necessary adjustments were performed to establish
k9 guidance on the upper right side which had number six in Christ bite prior to treatment
these PSN's made of obsidian lithium silicate ceramic pressed metal have great strength and
are particularly suitable where traditional pfm failed this obsidian combo restorations
enable good aesthetic results to be achieved and the patient was very happy with his new smile
you