Bonding veneers onto cementum?
I have a patient that wants to do upper 8 and lower 6. My questions is how would you prep/bond the canines but more importantly the first premolars? The gingival margin will be on root surface. Those teeth are completely virgin.
1) Normal veneer prep and bond
2) full prep and cement with rmgi (lots of extra tooth removed)
Would love to see differing view points and the reason for each?
Is tissue grafting out of the question?
This picture doesn’t tell the whole story? Smiling, repose, full face?
Lower anteriors are Supra erupted. Is there a reason?
I would consider bonding first on the laterals and canines and redoing the crowns on 8 and 9. After a wax up of course.
I notice 10 and 11 are a little more apocal than 6 and 7 too.
Just some thoughts...
Hi Jonathan-
There are several issues to consider here when doing a case like this...
The original questions as posed: Can I bond veneers on to Cementum? Well you can of course and I understand why you would consider this because in the end it saves tooth structure. However, will it work long term?
If you look into the literature on bonding to dentin and cementum, there are several issues:
- The support of the ceramic is different than if you bond to enamel.. the biomechanics of the restoration and tooth change and ceramics become more brittle. This often can result in cohesive failures (where part of the veneer fractures and part stays on
- The prep becomes more significant than you think because the more apical you extend it, the more tooth structure you need to remove in the body to help with "draw" and will in the end sacrifice enamel more incisally.
- The long term bond to dentin deteriorates over time. The bond to cementum deteriorates even faster. This can lead to adhesive failures and a higher chance of staining and decay
- Some research shows that having the margin out of the enamel results in failure rates at 10 years over 10x more than if it were in enamel.
So... will it work long term with veneers. IMO likely not.
So, now we are really left with 2 options: crowns or interdiciplinary dentistry.
What I would likely look to do is try and figure out why the abfraction and erosion areas are there in the first place... Can you fix them with grafting alone? If you fix them with grafting, will they come back in the future? Does the patient need orthodontics.
IMO, there is likely an occlusion issue that is causing these defects here (not enough info yet). My question would be if I could fix the occlusion issue with restorations alone. If so, I would likely do grafting and then veneers/partial coverage restorations. If I cannot fix the occlusion with conservative restorations, I may look at Orthodontics first. At this point I don't know... but I think those are the things that you should look at for the best chance of long term success.
Thanks for the opinions...great to get feedback and other view points.
While I think we as dentist, myself included, would do the interdisciplinary care of ortho, gum grafts etc, I often have difficulty getting acceptance for it. Trust me...I tried on this case. The first treatment plan was very conservative: bleaching and just doing 8 and 9. The patient never even bleached even though he got the trays made. We have discussed the options above and patient still wants a new smile without ortho and Ctgs. So, do I take on the case? I'm leaning towards doing it, bonding emax where there is enamel, cementing with rmgi where there isn't (so full coverage crowns on 5,6,11,12)
Interdisciplinary Case:
Pro: will last longer
Con: more time and more money
Crowns:
Pro: Time and money
Con: redos down the line
A lot of times time and money win out....time is more of a factor in this case.
As always Mike's comments are spot on. I definitely think there are some occlusal factors that have caused the abfractions and just looking at one picture, there may be a constricted envelope of function. So as Mike alluded to, more questions than answers right now but I definitely would be hesitant to simply do veneers right now.
Does he have a high smile line???
If not.. for the sake of simplicity have you considered bonding composite to the cervical areas and veneering coronally to that? I would present that as an option when talking about the other modalities.
good case.
I have cases like yours and it always drives me crazy how to approache them. I asked a lot dentists how to approach theses cases like you.
What I am looking for in these type of cases:
1. Are those abfractions active? means : Did their got bigger with time?, if yes it might be occlusal problem or perio and we might adress them first
2 Are those dark roots actually root caries?, if yes, we have to work on biomechanical ( enviromental) problem
All of the above have different approaches.
If patient has high lip line and wants more cosmetic approach I would consifer as mentioned above to bond Laminates on enamel and do soft tissue grafting. If surgery out of question and Ortho I would extend my margin onto dentin.
These type of cases discussed in detail in Galip Gurel book, I also asked Kois about it. Kois prefers as I mentioned to stay in enamel but will go onto dentin if necessary. Gregory
Gurel book is great. He is one who suggests that laminates are 10x more likely to fail if not in enamel after 10 years. You have to do what you have to do though.... I would extend into Dentin before I would prep crowns probably.
Not to hijack this thread, but I have wondered what the thoughts are when we are discussing full coverage of a posterior and we are finishing in cementum on the margin. Let's say we are doing an emax crown on #3, traditional prep, no enamel in moderate areas of the margin. Clearance gives us 1.3 mm, so we should be bonding this tooth in even though we have a retentive prep as our emax is not sufficient thickness for RMGI. Does that prep design overcome the fact that we are bonding to cementum? Is it better to go with another material and use RMGI? Or is either way clinically acceptable? Let's pretend they are all sold out of zirconia speed fire ovens and that's not an option right now ;)
Fwiw, I've been a fan of multilink for years. I keep all my preps in enamel and conservative when I can, which is the vast majority of the time, but as more studies are performed and research comes back, I do wonder what the current thoughts are out there.
With a traditional retentive prep you will generally be in dentin or cementum most everywhere except potentially some narrow bands of enamel at the margin. The difference from a veneer in terms of breakage is likely due to the fact that the ceramic on the axial walls of the crown are often 2-3 times as thick as on veneers and the biting forces are compressive vs. shear and generally confined to the thick ceramic on the occlusal surface.
On 1/24/2018 at 1:54 pm, Gary Templeman said... With a traditional retentive prep you will generally be in dentin or cementum most everywhere except potentially some narrow bands of enamel at the margin. The difference from a veneer in terms of breakage is likely due to the fact that the ceramic on the axial walls of the crown are often 2-3 times as thick as on veneers and the biting forces are compressive vs. shear and generally confined to the thick ceramic on the occlusal surface.
Thanks for the reply, Gary. That's pretty much what I have always figured, but I always like to check in to see if anything has changed as new studies come out. Appreciate the reply.
