Best restoration option for me (post-root canal retreatment). Pics included.

[John_D]

Hello dentists! I just underwent root canal retreatment for my molar 46. I want your professional opinion on what's the best restoration option for my case (resin, amalgam, inlay, onlay, crown, or any other).

By best, I mean the most conservative and durable one. From what I've read (I'm no dentist), I'm considering an amalgam, taking into account its durability, conservativeness and the big hole (sorry for the non-technical term) in my tooth. I understand the amalgam is better vs. the resin in cases such as this, but I'm not so clear on why not choosing the other options, so far I'm preferring the amalgam for the sake of conservativeness, but I'm here to reach out to you guys, to see if you can change my mind. I also understand (not completely) the state of the cusps has something to do with it.

Thanks in advance.

John.


Edit: I just found out gold fillings exist, now I think that'd be my best choice. What do you think?

 

[John_D]

One last pic:

 

[MattKW]

At a minimum you would shorten the cusps and fill the entire pulp chamber and over the cusps with amalgam. Composite is a useless material for these things - you've gone to a lot of effort to redo this RCT, and I would go for strength and durability over appearances any day.
Usually, I'd put in a wrought stainless post or two as well, but your canals have been heavily flared so this would be risky.

• However, if you can afford it, I'd do a cast gold post-and-core so that the gold snugly fits in the farthest back canal (distal canal), then a porcelain-fused to gold crown with 2-3mm gold margins for best fit and cleansibility. No-one will see the small gold margins back there.

As an aside, you have a large amalgam in the upper right tooth. That would benefit from a crown or fractures are possible.

 

[John_D]

At a minimum you would shorten the cusps and fill the entire pulp chamber and over the cusps with amalgam. Composite is a useless material for these things - you've gone to a lot of effort to redo this RCT, and I would go for strength and durability over appearances any day.
Usually, I'd put in a wrought stainless post or two as well, but your canals have been heavily flared so this would be risky.

• However, if you can afford it, I'd do a cast gold post-and-core so that the gold snugly fits in the farthest back canal (distal canal), then a porcelain-fused to gold crown with 2-3mm gold margins for best fit and cleansibility. No-one will see the small gold margins back there.

As an aside, you have a large amalgam in the upper right tooth. That would benefit from a crown or fractures are possible.

Thanks for your advice Matt. I think I'll go for gold.

However, given the amount of lost tooth, can I still opt for a filling or inlay? or an onlay/overlay?

How many cusps remain in the tooth? 3? 2? none?

 

[MattKW]

An onlay would be OK. You basically have only 2 cusps left, and if they fracture, the fractures usually go deep under the gum and the tooth has to be extracted. Don't risk it - those cusps have to be covered (onlay or cusp-capping) or enclosed (crown).

 

[John_D]

An onlay would be OK. You basically have only 2 cusps left, and if they fracture, the fractures usually go deep under the gum and the tooth has to be extracted. Don't risk it - those cusps have to be covered (onlay or cusp-capping) or enclosed (crown).

Thanks again Matt. I'm pretty set for a gold onlay now. According to "Effect of different onlay systems on fracture resistance and failure pattern of endodontically treated mandibular molars restored with and without glass fiber posts." By Zalameh et. al. (2010):

"Statistical analysis showed that restoration of endodontically treated teeth with gold onlays improved fracture resistance when compared to glass ceramic or resin composite onlays. The presence of a fiber post significantly improved (P<0.045) fracture resistance of gold onlays from 2271 to 2874N while it did not influence the performance of the other two groups. Fractographic analyses revealed that the presence of fiber post resulted in more restorable fractures due to better stress distribution of the applied load."

Can I still get this fiber post taking into account the heavy flaring you mentioned a few posts ago? Is this fiber a better material than any other post (gold, composite, etc.)? Does the cost of the onlay vary significantly with/without the post? (I have the quotation without already).

 

[MattKW]

A fibre post won't work with your canal flaring; that's why I suggest a cast post which is tailor-made to fit the canal perfectly and without the need to drill away any root. Premade posts like fibre of stainless steel require that the canal be drilled to fit the shape of the post. With cast gold, you simply remove the root filling to the depth required, then take an impression, and the lab makes it up. Also, the core is part of the same casting, so you don't have a separate post and core; it's all one piece. Admittedly, not many young dentists are familiar with this technique. There is great difficulty comparing the systems in vivo because there are so many variables. The study you quote is in vitro and does not compare cast gold posts with fibre posts; it primarily compares different types of onlays with or without a post (in this case only fibre).

 

[John_D]

A fibre post won't work with your canal flaring; that's why I suggest a cast post which is tailor-made to fit the canal perfectly and without the need to drill away any root. Premade posts like fibre of stainless steel require that the canal be drilled to fit the shape of the post. With cast gold, you simply remove the root filling to the depth required, then take an impression, and the lab makes it up. Also, the core is part of the same casting, so you don't have a separate post and core; it's all one piece. Admittedly, not many young dentists are familiar with this technique. There is great difficulty comparing the systems in vivo because there are so many variables. The study you quote is in vitro and does not compare cast gold posts with fibre posts; it primarily compares different types of onlays with or without a post (in this case only fibre).

Thanks Matt. When you talk about post and core, are you talking exclusively about a crown (not an onlay)?

If I go to any prosthodontist and ask him for a gold onlay, am I all set? I mean: are all onlays made the same? Or must I ask specifically for an onlay consisting of a single piece gold casting (post and core)?

I think I'm confusing onlay and crown terms... my bad.

 

[MattKW]

The post is like the reinforcing bars that go into the concrete base (core) of a house. The post can be separate from the core (Usually), but can be a single casting.
An onlay is like keeping the original brick walls (your natural tooth) but placing a new roof over the walls. A crown is like replacing the walls and roof together (usually the case).

 

[John_D]

The post is like the reinforcing bars that go into the concrete base (core) of a house. The post can be separate from the core (Usually), but can be a single casting.
An onlay is like keeping the original brick walls (your natural tooth) but placing a new roof over the walls. A crown is like replacing the walls and roof together (usually the case).

View attachment 2523

Keeping up with my conservativeness rationale, I'm currently (not definitely) inclined for the gold onlay because it is less invasive than a crown: In case it fails, I can replace it with a full crown (is this true?).

Given that I currently have a periapical lesion, I'm confused on whether I should prioritize avoiding microleaking or a potential fracture.

I'm mentioning this because I had the tooth exposed with just the amalgam for 12 years, and for 2 years after that with only a temporary cement and I didn't suffer a fracture. I'm relatively young (turning 30 in a month) also.

From what I've read, an amalgam is better vs. a gold onlay to avoid microleaking. If I want the lesion to heal faster is it possible to get an amalgam first until the lesion heals and THEN get the definitive restoration? or this just doesn't make any sense at all?

As a definitive restoration, is a gold overlay any better than an onlay? Is it necessary in my case?

Is an onlay the same as an "endocrown"?

 

[MattKW]

1. Leakage or fracture? Equally important. Leakage will lead to re-infection of the canal; fracture will lead to loss of tooth completely.
2. Sure, things went well for 12 years fracture-wise, but it only takes 1 day for it to fracture. Actually had a patient this morning - I did the RCT 10 yrs ago, and she came in with hopeless fracture today. She never did the crown I'd advised. Now it'll be an implant.
   
3. The most likely penetration of microleakage is through the core, which is partly why I don't do composite cores. A gold post/core, or amalgam core will equally stop microleakage.
4. Sure, get the amalg first if you want, but don't leave the cusps unprotected. Either reduce them and cover with amalgam, or at least place a long-term temp crown (a bit of a waste of time IMHO).
5. I have misguided you in the terminology - sorry. I mean to do either an overlay or a crown (forget onlay). If you are going to do full gold, then an overlay would be OK; if you do a crown, then either full gold or porcelain fused to metal.
6. Don't even worry about endocrowns. I had to look that one up, and it just introduces all sorts of technical problems and I can't see any benefits.

 

[John_D]

1. Leakage or fracture? Equally important. Leakage will lead to re-infection of the canal; fracture will lead to loss of tooth completely.
2. Sure, things went well for 12 years fracture-wise, but it only takes 1 day for it to fracture. Actually had a patient this morning - I did the RCT 10 yrs ago, and she came in with hopeless fracture today. She never did the crown I'd advised. Now it'll be an implant.
   
3. The most likely penetration of microleakage is through the core, which is partly why I don't do composite cores. A gold post/core, or amalgam core will equally stop microleakage.
4. Sure, get the amalg first if you want, but don't leave the cusps unprotected. Either reduce them and cover with amalgam, or at least place a long-term temp crown (a bit of a waste of time IMHO).
5. I have misguided you in the terminology - sorry. I mean to do either an overlay or a crown (forget onlay). If you are going to do full gold, then an overlay would be OK; if you do a crown, then either full gold or porcelain fused to metal.
6. Don't even worry about endocrowns. I had to look that one up, and it just introduces all sorts of technical problems and I can't see any benefits.

Right now I don't have the $$$ to afford the gold overlay. I can ask the Dr. who retreated me for a new temporal cementation. Considering a tentative end of July date for the definitive restoration, is it better to get an uncovered cusps amalgam ASAP? or is this "re-cementing" enough?

Did the retreatment introduce a fracture? I noted right in the center of the after image (first post, second image) something like an X figure (a crack?) between the 3 root fillings. I'm actually feeling a little achey (before retreatment, it was a 1/10 ache on any random day, now it's the same but it increased to a 1.5/10)

 

[MattKW]

Amalgam will be fine as long as you reduce and cover the cusps; then go to crown later. There is no crack.

 

[John_D]

Amalgam will be fine as long as you reduce and cover the cusps; then go to crown later. There is no crack.

Thanks for your help Matt! When the gold overlay is set, will it beep whenever I pass thorugh those metal-detecting gates? what about when security scans me with those detecting flat sticks?

 

[John_D]

Amalgam will be fine as long as you reduce and cover the cusps; then go to crown later. There is no crack.

I'm getting the amalgam tomorrow. I've been reading about the overlay and I got some interesting quotations regarding the restoration of a RCTed teeth. I have yet to understand the gold overlay process, if it implies a simple casting piece including the post, if the post can be avoided, what's the best cementation, etc. also what's the way to perform the procedure:

" A ferrule of 1-2 mm of tooth tissue coronal to the finish line of the crown significantly improves the fracture resistance of the tooth and is more important than the type of the material the core and post are made of"

- Hmmm... interesting...

followed by this:

"The most important factor influencing whether a post will be necessary is the amount of supporting tooth structure remaining after crown preparation and the development of a ferrule. If three supporting walls of dentin remain, a post is not necessary. All metal posts, regardless of design or type of cement used, transmit forces developed during mastication to the root of the tooth, and thus, can promote fracture over time if the root is structurally compromised."

- Does my tooth have three supporting walls of dentin? or were all removed for the treatment? Does the affirmation about metal posts include the one you mentioned earlier in the gold casting?

"By tradition, some dentists continue to use metal posts to retain bonded composite restorations while they accordingly should be replaced by fiber-reinforced resin-based posts which are more protective of remaining structure; or possibly by no posts at all. This is supported by the fact that a ferrule should be obtained on all endodontically treated teeth. If a 2 mm ferrule can be obtained for any protective restoration, a post is not needed to obtain a bonded buildup. A ferrule is generally considered to be extremely important to prevent dislodging forces that will lead to coronal leakage. Cusps should be covered if structural loss has damaged marginal ridges or undermined coronal walls."

- OK, I get it. I must cover 'em cusps! Now regarding the ferrule, Can a 2mm one be obtained from my tooth?

And the final one:

"...This research suggested the following: access opening (5% reduction in stiffness), occlussal preparation (20%), loss of one marginal ridge (46%), loss of two marginal ridges (63%); thus, the conclusion to preserve marginal ridges whenever possible."

- Is my tooth then at 63% (or more) of stiffness lost? What's the probability of a fracture following the retreatment? In a year? 5? 10? 20? ...50?

 

[John_D]

Oh... I forgot: Is it possible to get the amalgam (and later the overlay) without reducing the cusps? If not, does it make any difference to reduce them for the amalgam, before getting the overlay? I remember reading something about how the amalgam requires more tooth to be removed.

 

[John_D]

I just got the amalgam. The bad news is the Dr. (not the endodontist who treated me initially) noticed a fracture line inside my tooth. He handed me the mirror to show me the line but I couldn't see anything, really. He was using small magnifying binoculars and asked me if the endodontist used any magnification. I said no and he patted me in the back... I may (may?) have cracked tooth syndrome. I can actually tell the 1.5/10 pain is "different" from the pre-treatment pain, it feels a little more on the upper side, and as the symptoms of the syndrome say, the pain comes and goes.

He then reduced the cusps to flatten out the tooth, and when I told him I was considering a restoration with a post, he literally said "No ****ing way!!!" as he proceeded to explain me how the post would increase the fracture, doing an analogy with construction stuff, and further mentioning something about the gold overlay where the forces would not balance out in a hard surface, considering the new found fracture. The thing we don't know is if the fracture actually goes deeper than the cementing (not the amalgam) I have right now. Can I find this out with X-rays? dyes?

He also told me to use glass ionomer for the cementing of the restoration (a crown), as it is the best material to avoid a major fracture.