Your Teeth are Cracked
I hear this a lot from patients. Â "My dentist told me that my teeth are cracked and I need crowns." Â
 I go into the mouth expecting to see a severely bombed out tooth with an extensive amalgam.  What I typically see is what is below.  Some old amalgams? Yes.  Some visible cracks?  Yes.  But is this something that requires a crown?  In my opinion, no.   In the case below, treatment can vary significantly depending on the severity of the size and wear of the amalgam but in my opinion, as a professional, we are doing too many crowns.  You can be more conservative and can leave more tooth structure behind which benefits the health of the patient.  Simply removing the amalgams and removing the cracks will reveal a tremendous amount of healthy tooth structure behind.  As you can see from the initial clean out of the amalgams, the teeth do not need crowns but well functioning inlays and onlays.  A few tips if you prepare your teeth this way- no undercuts whatsoever in the preps- especially with the Omnicam.  If you have undercuts, you will spend a tremendous amount of time fitting and adjusting your restorations and you will not have the ability to properly seat your restoration.  You also want to make sure you leave cusps behind that are "thick enough."  My general rule of thumb is that I prefer that my functional cusp is at least 2mm thick and the non functional cusp is 1.5 mm.  Any less than this, we will have a potential problem of having thick and strong enough porcelain but a weak substructure behind.  The preps below just need simple refinement from this point. You do not need to cover all the cusps and for sure we do not need to remove any additional tooth structure other than cleaning up the stained cracks that are present.  So next time you see old beat up amalgams, instead of just cutting the teeth down completely, take the time and effort to properly evaluate what the teeth need and save tooth structure.  No matter how good your restoration, at some point, it will need to be replaced and the more healthy tooth structure you can leave behind for the next guy, the better it is for the patient. Â
Very controversial. You are leaving cracks in the tooth. What if they go on root surface? you simply don't know. I have had to take out teeth where these cracks go on root surface?
And I've seen teeth like these with no additional treatment function for years to come. But yes I agree- very controversial to say the least but conservative partial coverage restorations can serve the patient well for years to come without crowning everything.
It's a race against time. The patient has strong enough fxn & parafxn to create extended cracks from fissure lines, wide enough for corroded amalgam to stain. Seems most all my patients would rather do full coverage crowns beyond fractures than to wait and see. Once the tooth becomes symptomatic, seems we are playing catch up and even with endo, replacing the inlay/onlay with a crown (now excessive treatment) may NEVER get the tooth comfortable......good old crack tooth syndrome. I agree to give the patient the option (as I always do) but as soon as I say, "but if" then they take the lesser better odds treatment, crown.
Sam, I totally agree that in a very many cases, especially like the one that you have shown, partial coverage is very frequently a better service for the patient. My only comment is that I have found after a very many years of doing these that it is better to cover the cusps, and place finishing lines on the vertical axis of the tooth in order to avoud the marginal cupping that occurrs on the occlusal surfaces.
An army dentist friend of mine calls it rape dentistry; crowning everything in sight.
I think of that term before going to town on a decent tooth with my black stripe diamond.
I ask myself; would I do it on myself?
Thanks cerecdrs contributors! Great site!
I have a color photo enlargement in my wet lab that I look at everyday. It was of a patient that had an asymptomatic DO amalgam on an upper first bicuspid. I saw a dark stain going over the mesial margin. I gave the options for treatment and, of course, he decided to wait on any restorative treatment. Three weeks later I was extracting the tooth due to a nasty vertical root fracture. Now he will need a difficult implant due to the spacing and bone. As dentists, we need to do better than watch disease or just observe symptoms. My clinic judgement said that the tooth needed restoration but I did not give the patient what he needed, even though I informed him of the consequences of his choice.
To Lynn,
Sorry. Total baloney. This is my big problem with dentistry. From exaggerated benefits (non existing) of teeth "cleanings" to mandatory prophylactic wisdom teeth removal to crowning every crack -- fear based "testimonials" rather than solid evidence and research backing up recommended treatments. A dentist once showed me an photo enlargement of a dark amalgam stain in a vertical crack in the mesial surface of my #7 and recommended IMMEDIATE crowning -- citing the exact risk you claim. That was 20 years ago! So what? And so what ... to your "3 weeks later scare story" which I'm sure you've probably used numerous times to guide patients into crowns that were just as likely to be unnecessary. Do you have multitude of photographs of similar patients who disregarded your advice -- or is it just that one? How often will cracks propagate to the root? How often will they just remain dormant? In the absence of solid evidence (which will never happen in dentistry) and whether it is dentistry or medicine -- sensible patients will demand and honest practitioners should always advise the most conservative mode of treatment.
