Enamel defect

RE: Enamel defect

Evelyn Barbour-Hill — Tue, 09 Apr 2019 23:21:10 GMT

[quote user="Alexander Geddes"]However I think applying literature from human dentition and logic from what we know about canine dental composition; I think the enamel probably plays a significant role in strength composition.[/quote]

But, to put it crudely, human teeth have thick enamel while canine teeth have thin enamel.

[quote user="Alexander Geddes"]Its really interesting you bring up rods and tubes - but I was hoping you could clarify your thought process. I presume you are thinking tubes are stronger than rods hence dentin is stronger than enamel[/quote]

No, I wasn't thinking that at all. A solid steel rod is not much stronger than a steel tube of the same diameter. Stresses are concentrated on the outside. A one-year old tooth with wide pulp is not much weaker than a four-year-old tooth with narrow pulp.

[quote user="Alexander Geddes"]the OP's tooth appears to have deposited tertiary dentine (based upon visual inspection and radiographic evidence of coronal pulp obliteration). Logically the organisation of this dentine would provide a weaker construct - and hence how much is this tooth weakened by the presence of this substance I wonder?[/quote]

Now that you will have to explain.

[quote user="Alexander Geddes"]I'm not convinced the OPs tooth is evidence that we don't get ongoing damage to the surface of these teeth - this photo illustrates only one time point.[/quote]

But the deep staining indicates that wear is not proceeding, or not proceeding fast anyway.And the edges of enamel are visibly rounded – they're not cracking away.

[quote user="Alexander Geddes"]What are we achieving with composite restoration though? Maybe creating that uniform tooth surface will help minimise further damage to enamel ridges. But we know composite is poor in shear and so these restorations deteriorate over time.[/quote]

Well, that rather depends upon how competently the restoration is done. I certainly think that your comment about "watch the composite chip off" was unjustified.

[quote user="Alexander Geddes"] We suspect we have a weaker tooth which we can improve with crown placement. Not in this case but if there is marginal defects it may help local perio. The protection provided by crown placement removes the concern for further damage to this tooth which may cause discomfort, pulpitis, reduce tooth integrity and provide the need for repeated composite restorations.[/quote]

Bearing in mind of course that crown preparation weakens the tooth.

RE: Enamel defect

Alexander Geddes — Tue, 09 Apr 2019 16:54:48 GMT

Haha Evelyn some of these Emoji's I really have to try and figure out what they are doing!

I mean without derailing the current thread I suggest what I have described is the current norm; customised to each of our patients accordingly.

I was admittedly bold in saying the tooth must be more prone to fracture; we don't have that information. However I think applying literature from human dentition and logic from what we know about canine dental composition; I think the enamel probably plays a significant role in strength composition.

Its really interesting you bring up rods and tubes - but I was hoping you could clarify your thought process. I presume you are thinking tubes are stronger than rods hence dentin is stronger than enamel? If so does that not suggest that a mature tooth with significantly more dentin will be significantly stronger by that logic?

I think that point also brings up an interesting thought - Whilst we again cannot say certainly without histo - the OP's tooth appears to have deposited tertiary dentine (based upon visual inspection and radiographic evidence of coronal pulp obliteration). Logically the organisation of this dentine would provide a weaker construct - and hence how much is this tooth weakened by the presence of this substance I wonder?

I do agree crown preparation on a young tooth would not be recommended - I should have clarified my thought process there.

I'm not convinced the OPs tooth is evidence that we don't get ongoing damage to the surface of these teeth - this photo illustrates only one time point. Logically I would think exposed enamel ridges are inherently more vulnerable than a healthy contiguous surface. Equally, discrepancies in tooth surface should propagate forces differently.

What are we achieving with composite restoration though? Maybe creating that uniform tooth surface will help minimise further damage to enamel ridges. But we know composite is poor in shear and so these restorations deteriorate over time.

For many pets not chewing/working etc I agree that minimal work or maybe composite that will stand the test of time from a lack of forces is a good direction.

But for dogs playing/chewing heavily and working I think my above thoughts can justify my original comment for crown placement (after some maturation of the tooth): We suspect we have a weaker tooth which we can improve with crown placement. Not in this case but if there is marginal defects it may help local perio. The protection provided by crown placement removes the concern for further damage to this tooth which may cause discomfort, pulpitis, reduce tooth integrity and provide the need for repeated composite restorations.

RE: Enamel defect

Colin Baxter — Sat, 30 Mar 2019 20:13:40 GMT

Interesting discussion but over the years I've followed these teeth and find that they do become more eroded. Presumably because the dentine is porous and more likely to be worn away. I prep the areas involved and do restorations with resin composites. It seems that not only do they look better but the teeth last longer..

RE: Enamel defect

Evelyn Barbour-Hill — Fri, 29 Mar 2019 13:41:12 GMT

[quote user="Alexander Geddes"]My short hand for assessment/rads/cleaning[/quote]

Assessment in a consultation, sure, at least annually if not more. But annual GA for radiographs and cleaning???

[quote user="Alexander Geddes"]Thats a good point, we don't know compositions relation to strength though? What about in a young dog with very little dentine?[/quote]

A young dog's enamel is no thicker than an older dog's. Yes, relative to dentine, the ratio is greater of course; still doesn't mean the enamel makes any significant contribution to strength. And, you know, in a young dog where the dentine is relatively thin I don't believe the tooth is so weak that it's hanging on a knife edge saved from fracture only by the enamel. In fact if one ponders the relative strength of tubes and rods I suggest that the young tooth is not so much weaker than the old tooth.

And, one might also consider that in the young dog with relatively thin dentine the significance of removing tooth substance in order to place a crown is relatively greater.

[quote user="Alexander Geddes"]If you've got ridges of enamel from the defect, what if those are getting damaged and exposing new dentine at the dog chews and grabs things?[/quote]

But that just doesn't happen – as the OP photograph illustrates. (Different, of course in those fairly rare cases of overall defective enamel formation, where any remaining enamel is just waiting to fall off.)

And – if one does feel a need to treat the defects, a good resin composite restoration will be very satisfactory.

RE: Enamel defect

Alexander Geddes — Fri, 29 Mar 2019 00:18:05 GMT

My short hand for assessment/rads/cleaning

Thats a good point, we don't know compositions relation to strength though? What about in a young dog with very little dentine?

Yes in this case agree irrelevant. If you've got ridges of enamel from the defect, what if those are getting damaged and exposing new dentine at the dog chews and grabs things?

RE: Enamel defect

Evelyn Barbour-Hill — Thu, 28 Mar 2019 23:41:16 GMT

[quote user="Alexander Geddes"]Annual cleans?[/quote]

Annual cleans?

[quote user="Alexander Geddes"]this tooth must be more prone to fracture. [/quote]

I cannot agree. Why would it be? The contribution of the thin layer of enamel to the strength of a dog's tooth must be minimal.

[quote user="Alexander Geddes"] And if the defects are at the gingival margin, those both seem like good reasons to consider a crown...minimise fracture risk and reduce plaque retention.[/quote]

But in the OP case the defects are not at the gingival margin, so plaque retention is irrelevant.

And one might mention that crown placement requires removal of further healthy tooth substance (but, I admit, very little if you employ the modern minimal-preparation cobalt chrome type of crown.)

RE: Enamel defect

Alexander Geddes — Thu, 28 Mar 2019 01:56:28 GMT

Annual cleans?

I agree anecdotally we seem to see a lot with a variety of defect severities that have apparent tertiary dentine and continue to mature. But I'm not sure what literature we have to support that? And what about sensitivity of these teeth? Something thats very difficult to quantify! I guess for me it depends on what the dog is doing, if its going to be working or being an idiot, heaving chewing etc this tooth must be more prone to fracture. And if the defects are at the gingival margin, those both seem like good reasons to consider a crown...minimise fracture risk and reduce plaque retention.

RE: Enamel defect

Evelyn Barbour-Hill — Fri, 08 Mar 2019 19:09:02 GMT

[quote user="Alexander Geddes"]annually at the cleans![/quote]

Er.... annual cleans?

[quote user="Alexander Geddes"]Not being able to quantify the risk of endo at a young age would lead me to debride enamel, make sure the crown is as smooth as possible and bond it. For me this is a good one for a crown if the owner is keen![/quote]

Having been taught by Peter Emily about 30 years ago that there was only small risk of any adverse effects beyond the cosmetic in this condition, I've been happy to advise ever since that a certain amount of monitoring was all that was necessary... and my observations have justified my opinion. Teeth like this may look 'orrible but they rarely come to any harm.

RE: Enamel defect

Alexander Geddes — Fri, 08 Mar 2019 18:30:39 GMT

I agree with you, at this age I would monitor going forward. Acid etching is not a benign action and do you risk initiating a problem by interfering here? - I don't think theres a right answer!

I think its at higher risk of endo from a structural integrity point of view, fracture etc. but I think if its doing well at this stage its unlikely to be at higher risk of endo from the hypoplasia point of view - as Evelyn said tertiary dentin has done its thing here (pending serial rads). I would still radiograph it annually at the cleans!

Interesting case because hind sight is a wonderful thing! I would admit that my perspective would be quite different if this was a young dog! Not being able to quantify the risk of endo at a young age would lead me to debride enamel, make sure the crown is as smooth as possible and bond it. For me this is a good one for a crown if the owner is keen! Or watch the composite slowly chip off!

RE: Enamel defect

Evelyn Barbour-Hill — Fri, 01 Mar 2019 19:11:07 GMT

[quote user="Rob Davis"]and seal the dentine tubules with a bonding agent[/quote]

I'm not so sure they need sealing here. I think the dentine has already supplied all the defence it needs.

[quote user="Rob Davis"]as it is at significantly increased risk of developing endodontic disease.[/quote] But is it, though? I'm not sure that it is.

RE: Enamel defect

Rob Davis — Fri, 01 Mar 2019 15:30:59 GMT

What Evelyn said. Is there any history of trauma during enamel formation (I think around 2-12 weeks old from memory), bitten by mum etc?

I would probably clean up the tooth, remove any loose enamel and seal the dentine tubules with a bonding agent, though how much difference this will make is debatable. I do think it would be important to radiograph this tooth every 6-12 months or so as it is at significantly increased risk of developing endodontic disease.

[quote user="Evelyn Barbour-Hill"]By the way, and merely coincidentally, I wonder what the little density stuck on the201 is?[/quote]

I'm going for a bit of muck on the sensor - there are a few other smaller spots elsewhere.

RE: Enamel defect

Evelyn Barbour-Hill — Fri, 01 Mar 2019 14:50:18 GMT

Well, there's certainly no reason whatever to extract it.

Interesting, the whole tooth looks just a little irregular in shape, especially at the "cervical bulge'.

If you pick at the edges of the defect, does the remaining enamel seem solid, or is there any tendency to flake off? From the appearance in the photo, I'm guessing the former, which means some sort of insult affecting enamel formation while the tooth was still developing, not defective enamel all over (which anyway would usually affect other teeth too).

The staining of the exposed dentine and the narrowing of the pulp within the crown (compare it with the normal tooth) suggest to me that tooth has adapted well and it is highly unlikely that there is any sensitivity in the exposed area.

So monitor.

Although it would be fun to do some cosmetic restoration.

As ever, quite prepared to be corrected.

By the way, and merely coincidentally, I wonder what the little density stuck on the 301 is?

RE: Enamel defect

Miriam Lodewyks — Fri, 01 Mar 2019 14:04:05 GMT

Here's the xray