teeth grinding, aka bruxism

Do I suffer from bruxism?

In the States it seems that this word has entered into the patient’s vocabulary but few people in the UK know its meaning. It basically means the unconscious habit of clenching or grinding the teeth, usually manifested during the sleep.

Several studies suggest it may affect up to 1 out of every 3 adults. This would go more or less along my personal (probably biased) observation. Throughout the patient’s life it can have catastrophic consequences, specially if undiagnosed. And quite commonly the patients are not aware of the problem, even if the wear if as substantial as the one in the picture.

wear

Mind you, tooth wear is in a way a natural process of ageing but we should look into increased wear. A few centuries ago people’s teeth would wear down at a much faster pace due to mainly sand or dirt mixed with the food. Naturally tooth wear doesn’t bother anyone if life expectancy is short. We need to look into the fact that we are likely to live longer and longer so any signs of increased wear are to be noticed.

We don’t fully understand the mechanisms associated with bruxism, but it seems stress is our main suspect. The most common consequences are felt on teeth are restorations: wear, fractures, cracks, early failures of dental treatment. It can also cause significant muscle pain and temporal-mandibular joint disorders, which are in a way harder to treat.

We know how to deal with bruxism though and we’re quite efficient with that: providing the patient with an occlusal splint commonly know as night guard works 100% of the time, as long as it is worn regularly.

There are different types of these guards, but the only ones that I strongly recommend are Michigan splints. These are hand made by a very skilled technician so that they fit perfectly on the patient’s teeth, not too tight, not too loose, and are carefully adapted to his/her bite. This is an essential aspect in making it comfortable to use, long lasting and also safe. A badly designed night guard can actually cause irreversible modification on the bite and joints.

Not everyone who suffers from bruxism needs a splint, the dentist needs to evaluate the individual case, how bad the grinding is, and help the patient to decide to have one of these or not.

When teeth have already suffered significant wear, rehabilitation is always possible. In the case here (see picture above) we chose veneers, as a minimally invasive strategy which delivers long lasting results. Below is a picture of how I bond the veneers to teeth.1wear solved

cervical wear

It is extremely common to observe small defects on the areas of the teeth close to the gums. These are not decay (most of the times) and the patients may feel that there is a groove over there. Sometimes they are associated with increased sensitivity to cold or to touch, but often cause no major symptoms. We can call them abfraction lesions or simply cervical wear.

What causes these defects?

It seems that grinding or clenching the teeth may be the most important factor at the origin of this wear. Aggressive brushing worsens the wear.

What can be done?

The major concern with these lesions is that dentine becomes exposed. Even if there is no sensitivity associated, dentine is softer than enamel and throughout the patient’s life will wear at a much faster pace. Therefore covering the lesions may be a sensible approach on the long run. It doesn’t mean that we have to act immediately all the time we identify this type of wear. Monitoring with notes and pictures can be an option but when the defects are of a certain size I do advise to cover them with composite restorations.

The case shown below is of severe cervical wear and in my view restoring such big defects is paramount, specially if the patient is relatively young. I also provided the patient with an occlusal splint (night guard) to act on the origin of this problem.

How long should dental treatment last?

Most patients who need dental treatment want two things: 1) decent looking restorations that 2) will last a considerable amount of time.  But what is the definition of considerable amount of time?

I think this depends of the patient’s previous experience (some had very long lasting restorations and now expect the same of the new work, others got used to repairs or remakes every few months) and on each person’s definition of value for money.

So.. how long should dental treatment last? Most dentists would like to see the 10 year mark on their work. We know that while some of it won’t last that long, many others restorations will way surpass 10 years. The factors involved in treatment success are plenty and we can’t control all of them. But while I see the relevance of the question, there is another one which is even more important and that patient’s often don’t ask: how will my tooth look like when the restoration fails?

It is irrelevant to offer a solution for 10 years if it will kill the tooth in the end, or make it very complicate and expensive to restore again. My personal goal is to see most of my dental work to reach the 10 year mark without much bumps along the way. But the priority is that when it does fail, I (or another dentist) can simply redo it, without much fuss.

Our life expectancy is sharpingly increasing and at the moment  dental treatment, as with any other technology, is not necessarily focused on increasing longevity. We must assume it will eventually fail, 10-15 years later. What happens next is the question.

Minimally invasive protocols keep the structure of teeth as solid as possible which reduces the risk of complications and easy re-treatment when needed.

Below here is a case where we had to redo one crown and restore the adjacent teeth with veneers due to wear and failing fillings. Note the difference between the preparation of a tooth for a crown and for a veneer. Which of these teeth do you thing will be the first to fail?

R1

preps textWreview1

Do I really need a crown?

Crowns have been used in dental treatment for ages. It was in the 20th century that their use as a tooth restoration became widespread. Metal was initially the material of choice and later porcelain-fused-to-metal (PFM)

In order to have space for both materials – the metal and the porcelain – the dentist would need to reduce the tooth considerably. This reduction obviously weakens the tooth and also increases the risk of root canal therapy.

In the nineties the industry created alternatives to metal – first alumina, then Zirconia – which lead to the trend of metal-free crowns. It turned out this product was inferior to the PFMs. Without adding much aesthetic improvements, Zirconia actually requires even more space than the metal – meaning more tooth reduction.

There is a reason your dentist never shows you the preparation of a tooth for a crown – it’s frightening.

The main advantage of PFM or Zirconia crowns is being stiff and having decent aesthetics provided the tooth is heavily prepared.  But can we achieve the same resistance to fracture with pure porcelain and minimal tooth reduction?

Yes we can! The secret is in correctly bonding the porcelain to the tooth. And if we do so, we don’t depend anymore on the mechanical retention principles that guided dentistry for centuries. Bonding was the single most revolutionary technological breakthrough that happened in dentistry and we should use it.

Interestingly enough, unlike a crown, for a porcelain restoration to work well we need to reduce the tooth in the least possible way. This results in a stronger tooth and less risk of root canal treatment. And, by the way, much better aesthetics, true nature-like restorations and excellent gum health as we don’t need to hide their margins under the gum.

To make it clear: crowns do work, they can last for a long time, frequently without triggering the need of root canal treatment. It’s just that with today’s knowledge we don’t really need the unnecessary risk and long-term compromise. And quite frankly overlays or onlays look much better. So, do you really need a crown? No, you don’t.

porcelain overlay

microdentistry

Some hesitations on what to write as my first post with content. I thought about what’s the one thing that truly changed the way I practised dentistry. Without a doubt, that is magnification.

It’s not difficult to understand: the more you see, the more accurate you can be. And minimally invasive dentistry is all about precision.

A dentist is not only about that, of course. Making the right decisions, planning carefully and knowledgeably the cases, listening to the patients’ concerns. But when it comes to the all or nothing moments of the procedures, loupes or microscope are essential.

trying in an overlay