Planning a Big Case

[Brett Hansen CDT]

We have a big case coming in to our lab. Full maxillary arch restoration and a bridge from 20-29 on the mandibular arch. The patient has implant crowns on 18,19 and 30, 31. The doctor had another lab fabricate temporary bridges on the models that are in the following pictures:


The doctor wants the final prosthesis to be screw-retained zirconia. My plan is to have the doctor take impressions of the the maxillary and mandibular arches with the temporaries in place. I will get multi-abutments so that I can design the prosthesis with the access holes on the linguals where needed. I am going to design the mandibular bridge first by morphing the scan of the temporaries onto the scan of the working model. Then I will have the doctor try in the mandibular bridge and take a bite so I can fabricate the maxillary prosthesis. Then profit!!

My questions for the panel are:

Is there a better way to get an accurate bite registration? This has been the biggest hurdle on these
types of cases for us in the past.

We want to do this in monolithic zirconia(the patient has a very hard bite). I have a 4 axis Zeontec Mini Mill. I don't think I can mill an accurate, screw retained prosthesis for this case on my mill. Is that correct?

If I can't do it on my mill, is it possible to outsource the milling and have the bridge returned to me in the presintered state so we can stain it before it is sintered? We use Zenostar T0 for all our zirconia bridges.

I would love to get some opinions on my plan for this case and any advice you may have. Thanks in advance!

 

[Brett Hansen CDT]

Update!!!

I have been thinking about how we are going to mount the maxillary edentulous arch to the mandible after we complete the mandibular restoration. Our plan is to have the doctor place the mandibular bridge first. I will use Triad and a couple of abutments to create a bar between the implants in 6 and 11. The doctor will then cut the temporary and remove 6-11 and put the Triad bar in its' place. Next he will take a bite with the maxillary molars of the temporaries in place. This should give us what we need to mount the endentulous maxillary arch.

I will post pics of this case as it progresses. The doctor wants to complete it by October so we have plenty of time. Feel free to critique my plan or offer suggestions.

 

[Brett Hansen CDT]

Update #2

I just found out I can have WPT mill the bridges for me and ship them back in the green state. So that issue is solved.

 

[Brett Hansen CDT]

I met with the doctor today. Here is a picture of the Restoration Plan I proposed to him along with an estimate of the final lab bill. I will continue to document this case as it proceeds. Hopefully the last post on this thread will be about how smooth the case went and how happy the doctor and patient were with the results.

 

[JMN]

Does the doc supply the impression copings you need for the max impression vs the completed mand or are they assumed into your price structure?

Why not design them at the same time? It is easier to fiddle something if you need to when you can spread the fiddliness between both arches.

 

[dmonwaxa]

@ JMN

It's a bit unclear with what you're asking ....but i do agree with designing both arches and fiddle with both at the same time and further fiddle (tweak) it, in the final arch.

 

[JMN]

@ JMN

It's a bit unclear with what you're asking ....but i do agree with designing both arches and fiddle with both at the same time and further fiddle (tweak) it, in the final arch.

He's line itemed just everything, including abutments, but the impression posts were not on the proposed bill. That many of them will not be cheap and it's easy to lose a piece of the puzzle when trying to think ahead on a complex case.

'impression posts vs completed mand' was an unneded attempt to refer to his step proposal, and ultimately more confusing than helpful.
Should've just said impression posts.

 

[dmonwaxa]

I think the impression posts are the doctors responsibility. Or are you refering to the implant analogs or replicas for the models?

 

[JMN]

Around here it varies on responsiblity or rather expectation.

 

[dmonwaxa]

Thought as much!

 

[grantoz]

I think you are under charging.aprox $3500 per arch is way to low on a case like this add an extra 3-5 thousand and you're about right .the only reason you should charge this low is to get practice on large cases.if something goes wrong your screwed ,everything takes twice as long to do polishing ,each firing ,cementing your cylinders, pink porcelain and so on .

 

[Brett Hansen CDT]

I think the impression posts are the doctors responsibility. Or are you refering to the implant analogs or replicas for the models?

The abutments have already been purchased and are in place in the patient's mouth. The doctor will be meeting with a sales rep from Straumann to purchase the correct abutment analogs to take the impressions.

Why not design them at the same time? It is easier to fiddle something if you need to when you can spread the fiddliness between both arches.

We are doing each arch separately because I feel like this gives us the best method of getting an accurate bite. The patient has four teeth on the mandible that won't be extracted. Once the mandibular bridge is in place, the doctor can remove the max temporaries from 6-11 and then take a bite with the posterior temporaries still in place so the patient has a firm stop. I also want to do the entire case monolithically. The doctor wants to see how the monolithic mandibular bridge looks first before agreeing to doing the maxillary bridge in the same fashion.

I think you are under charging.aprox $3500 per arch is way to low on a case like this add an extra 3-5 thousand and you're about right .the only reason you should charge this low is to get practice on large cases.if something goes wrong your screwed ,everything takes twice as long to do polishing ,each firing ,cementing your cylinders, pink porcelain and so on .

We haven't done many of these cases. I know I may be undercharging a bit on this one.

Thanks for the questions and responses.

 

[Al.]

Thats ALOT of work and risk for a small return. More than a "bit" underchaging.
I would not touch it for that price, not because I think im special but I could probably make more money with no stress mowing lawns.

If one cracks in lab and need to be remade ?

Should make it at least $300 + a unit not $200 and add charges for tissue porc and the screw retained labor at least $100 each not $33

if he complains its too high walk away.

 

[Brett Hansen CDT]

We are beginning to restore this case. We are going to fabricate the mandibular bridge first. It will be monolithic Zenostar and screw-retained. I ordered 2 non-engaging Straumann Titanium Temp abutments and 2 Nobel Biocare gold sleeves to fabricate a model verification jig. I am going to use the gold sleeves in the final prosthesis. Can I use the Struamann temp abutments in the final prosthesis also?

The mandibular bridge will be pretty easy. I have a pre-op model to guide my final design. The bridge will be monolithic Zenostar. The doctor was advised by a Straumann rep not to use Zirconia on the maxillary bridge because of the "clicking" noise the bridges will make when they come together. He advised that we fabricate the maxillary bridge out of Cr-Co and layer it. I really want to stay away from layered bridges. Will a layered bridge have any effect on the "clicking" noise? Does anyone know how the process works in getting a milled Cr-Co bridge from Straumann? All the Cr-Co bridges I have done in the past have been from Atlantis.

If we do end up layering the maxillary bridge, the estimate I gave the doctor on the price is going to increase substantially.

 

[corona]

the lower full zirconia will probably chip the porcelain off the upper if you go that way . no warranty expressed when that puppy comes back because porcelian chipped off . Make sure you get that across to the doc and the patient . better to do zir to zir for long term satifaction. When it comes to the jigs .... wouldnt it be better to pre cut the jigs and send segmented so you will be sure that you are getting a passive fit ? just cut them thinly and sharply and tell the doc to lute CAREFULLY (they tend to over do it and make a mess ) then after they are luted in the mouth ... ask him to perform a sheffield test . This is critical because all the work done after words doesnt matter if the case doesnt fit in the mouth passively . and regarding the clicking ....i think its silly .... people dont go around clicking their teeth .... natural or not . Not sure if the straumann rep is crossing a line there and dictating treatment planning .... who will be liable if it goes wrong ... the straumann rep ? i think not .

 

[Brett Hansen CDT]

When it comes to the jigs .... wouldnt it be better to pre cut the jigs and send segmented so you will be sure that you are getting a passive fit ? just cut them thinly and sharply and tell the doc to lute CAREFULLY (they tend to over do it and make a mess ) then after they are luted in the mouth

Interesting, I was thinking this very thing last night after I left work. Thanks for the advice!

I agree with you on the material choice. I hadn't thought about the zirconia mandibular making it more likely to chip the layered maxillary. The doctor was pretty insistant on going with a Cr-Co layered maxillary bridge. I feel like if I talk him into zirconia and the "clicking" is a thing, then it will fall back on me. I am going to present this information to him and see what he has to say. I still don't see how zirconia on zirconia would sound any different than zirconia on layered porcelain unless the layered porcelain was chipping resulting in a softer "clicking" sound.

 

[corona]

Interesting, I was thinking this very thing last night after I left work. Thanks for the advice!

I agree with you on the material choice. I hadn't thought about the zirconia mandibular making it more likely to chip the layered maxillary. The doctor was pretty insistant on going with a Cr-Co layered maxillary bridge. I feel like if I talk him into zirconia and the "clicking" is a thing, then it will fall back on me. I am going to present this information to him and see what he has to say. I still don't see how zirconia on zirconia would sound any different than zirconia on layered porcelain unless the layered porcelain was chipping resulting in a softer "clicking" sound.

yeah Brett , in the end we will give the clinician what they ask for .... that is not the issue . Informed consent is what the doc and the patient will need . Will the ceramic chip in the future ... who knows ....may not ... but studies show that if the patient is a "hard biter" or bruxism or not a class 1 patient , then chances increase significantly and YOU will be left holding that expensive bag to repair. I would tell him I would be glad to do it , BUT given how patient presents , it is not within the scope of the materials long term stability . IF the material chips , then a charged WILL be assessed , as you will have to most likely strip the entire bridge and essentially start over again . Remember , There is no more periodontical ligament to take the minute stresses of chewing and function , therefore a stronger material should be indicated . I wonder if the clicking is his insurance policy out of a bad situation and a way to get you to remake the case for free ? In any case ... We should probably know more about what kind of occlusion classifaction patient is presenting with before we go any further . Are we looking at pretty good CO ? What kind of cusp height are you dealing with ? Whats the AP spread allowing you to go back ? What kind of occlusion are you going to design ? Cuspid rise ? group function ? . Is the patient going to wear a NG for protection ? What are the patients chewing habits ? How old is the patient ? All these things matter and things i would like to know because material choices = all these things .... and we havent even talked about esthetics and your backdoor key /plan . something i always like to have ready for these kind of cases.

 

[corona]

Oh and by the way Brett , patient already is presenting with existing posterior crowns over implants as you have stated and shown in the pics . What are those made of ? The occlusal flat designs on those crowns do not indicate your normal occlusal wear patterns and are indicative of what your upper occlusion design is going to be , therefore a stronger material is already a better option .

 

[lcmlabforum]

I do not see an occlusal guard in the treatment plan . . .

 

[Brett Hansen CDT]

Update!

I have the lower model ready to go. I made a verification jig that the doctor used to confirm the accuracy of our master model. I have the sleeves for the two nobel multi abutments and I ordered two non-engaging vario-base abutments from Straumann. Once I get those I will scan and design the case on my 3 shape. We are pretty much just making the lower bridge with a flat plane of occlusion.

I am still trying to figure out what material to use for the bridge. We use Zenostar at our lab, but it isn't esthetic enough to use monolithically. lly, both arches would be monolithic, but the esthetic demands of the doctor means I will be at least layering the maxillary bridge once we get the mandibular bridge done. What material would you suggest I use for the mandibular bridge? If I use Zenostar, I will be layering it. I have no experience with how layered zirconia would hold up on cases like this. I would have done zirconia on the maxillary bridge and designed it monolithically on the lingual, but the doctor is insisting on layered Cr-Co because he was told that Zirconia on Zirconia sounds bad.(?) Is there a monolithic zirconia material that would be strong enough for the mandibular bridge and still provide adequate esthetics? The distance between the two anterior implants is about 21 mm.

Thanks for all the feedback I have received thus far. You guys and gals are amazing!!