Broken Teeth - Understanding Why Teeth Break and What To Do About It

If you have ever had the unpleasant experience of breaking a tooth you may likely relate to the common belief that it always seems to happen on weekends or after-hours. It is one of “Murphy’s Laws” – or so it seems. Like heart attacks and car accidents, it’s never planned or looked forward to. The usual explanation is “I was eating Jell-O (or a banana or something else soft) and it just broke!” Maybe if we’d of been eating ice, nuts or rocks we might have deserved it.

One might even ask “how could it happen when my last dental check up found that everything was just fine?” Good question! What causes teeth to break in the first place, especially if it isn’t necessarily due to what you chew?

Here are three things you should know about cracked teeth:
1. A tooth can crack before it breaks.
2. Some cracked teeth hurt, some don't.
3. Unlike bone, cracked and broken teeth don't heal.

Why do Teeth Break?
To better understand how and why teeth break you must look at this problem like a structural engineer. After all your teeth are structural objects powered by strong muscle forces used to crush grind and chew. They are also biological structures with a live nerve (in most cases) in the middle of them that has the ability to send pain messages to the brain. When a tooth breaks it diminishes your ability to support your bite, chew your food, be comfortable, look attractive – and it usually hurts!

Like structural building materials, a tooth is subjected to immense stresses and forces. When these stresses and forces exceed the tooth’s ability to withstand them something has to give; the stresses must be relieved. They do this by cracking or breaking away the part that is stressed. ]

Consider what would happen to a block of wood or concrete if placed under a big load. Now consider what happens if you further compromise its strength and support by cutting a deep groove down the middle of the block and increasing the load or pressure. Eventually, the stresses exceed the limits of the wood or concrete’s ability to resist, and it begins to crack or split apart usually right where the cut or groove was placed. Unless you are an engineer with a computer, you can’t predict when it happens. It’s inevitable – like a time bomb waiting to go off. But it doesn’t take an engineering degree to understand that excessive forces and stresses in structural objects can weaken and break apart those objects, especially if the object is already compromised.

This is exactly what happens with teeth that have fillings. When a tooth gets tooth decay the dentist drills it out and places a filling. However, this process is like cutting the tooth apart which leaves the sides of the tooth unsupported and without strength - yet still subject to the same biting forces as before.
If the filling just happens to be a silver-mercury filling, things can even be worse. Silver-mercury fillings (which are about 50% mercury by volume) very slowly expand over time. This means if you had a cavity filled many years ago, that the filling that was placed back hen has been expanding over these years in a very slow but steady manner.

So now there are at least two significant compromises to the tooth’s strength, one from the original problem (cavity formation), and the other from the fact that a wedge has been placed in the hole or groove which is expanding inside the tooth. So, not only is the tooth inherently weaker because of the cavity, but now we have the silver mercury filling expanding (metallurgists call this “creep and flow”).

As if that weren’t enough, mercury metal fillings expand and contract with temperature changes in the mouth (thermal cycling with food and drink). Do you remember before the days of digital when thermometers were made of mercury – because it expanded and contracted with temperature changes (rather predictably we might add)? Plus we are constantly chewing and grinding on our teeth, flexing and smashing them with pure muscle force from our jaw muscles. Whew!

The margins, or edges of the filling also eventually break down and allow leakage of oral fluids and bacteria, creating further decay and tooth breakdown. And then there is the rust (oxidation) from the silver mercury filling which corrodes the surface and edges of the filling.

No wonder teeth break! The mouth is a very dynamic environment! There are numerous forces working on the tooth to tear it apart. Once a crack is started in the tooth, ongoing forces cause the small craze line or crack to propagate deeper into the tooth until eventually the crack becomes a fracture. When weakened enough, the tooth will break, relieving the stress and creating a painful interruption to your day.

Usually broken teeth have been in the works for some time. This is what we mean when we say that a tooth can be broken before it breaks. A craze line develops and propagates deeper into a crack, which in turn fractures away a piece of the tooth. When and where is a random act of chance and you can’t predict whether the consequence will be major or minor. Murphy’s timing is perfect! Unplanned and unbudgeted, it forces a quick retreat to the dentist for inconvenient but unnecessary dental treatment.

Why unnecessary? Because even though you can’t predict when a tooth is going to break, you can predict that they probably will! Sometime, someday, somewhere, something bad is going to happen to a tooth that is already significantly compromised and has cracks in them. In the old days dentists thought it was a kind thing to wait until a tooth broke to fix it. “When this breaks, give me a call.” They often believed that it was “over-treatment” to take a tooth that wasn’t “broken” and didn’t hurt, and intentionally do a new dental procedure to it. Besides, unless it was really deserving of a more expensive restoration, it wasn’t “right” for a dentist to “fix” something that wasn’t really broken or hurting!

How times have changed! To be fair, modern materials and techniques are so much kinder to teeth today. And the culture and medical norms have changed from “disease medicine” to “wellness medicine” and from necessary to elective. Prevention and reducing risk-factors have finally upstaged disease. Seeing something coming at you from down the road is easier to plan for – but only if you can see it! And therein lays one of the problems! If a dentist (or a patient) believes that a tooth with cracks around an existing filling is not a problem because it isn’t “broken” or it doesn’t hurt (yet), then it isn’t going to be mentioned. That is why so many people are surprised when their tooth breaks apart. Truth be told, it shouldn’t be a surprise!

But again, to be fair, there may be a number of reasons why a tooth can break without warning, without knowing it is coming. Cracks in teeth usually cannot be seen on dental x-rays. And even though they can usually be seen when shining a bright light through the tooth (transillumination), sometimes they are not visible, as when they are under an existing filling. At the bottom of the cavity, in the corners of the “box” or grove made when the decay is drilled away, small stress cracks can form at these internal line angles and propagate and travel in an outward direction. They can be hidden from visual inspection, yet be present in the tooth nonetheless.

Too often, unfortunately the reasons for not seeing the cracks and disclosing them, rest in the treatment philosophy of the dentist and/or the wellness/disease philosophy of the patient. Some truly believe that “if it doesn’t hurt and it isn’t broke it must be okay”. This gambling disease-medicine mindset forestalls the inevitable and is akin to waiting for the heart attack before admitting there may be a problem or the need to begin exercising or dieting. The wellness mindset removes potential threats before they present themselves. It asks “what’s the best dentistry that can be done?” and then schedules and budgets it in over time if necessary. When proactively dealing with the problem, time can be a friend and an ally.

It is unfortunate when a patient arrives with a piece of tooth in their hand broken away from the side of a large mercury filling, saying that the dentist they saw last year before they moved, said that everything was okay, or flat didn’t tell them that it might break. I immediately know the mindset or philosophy of the dentist, the patient, or both. The problem is that “disease medicine” is still standard-of-care, meaning that it is still okay! It is driven by the thinking “Yes but - it doesn’t hurt!” or “Yes but - it isn’t necessary!” (For that matter – there are a lot of people without teeth who can successfully make the argument that teeth aren’t necessary!) This “need” thing strikes to the heart of the problem of “cracked teeth.” Some hurt. Some don’t! Those that hurt drive dental emergencies. Those that break often get root canals, gum surgery and new crowns. And just because it doesn’t hurt isn’t proof that there isn’t a problem. The absence of pain is not the evidence of health!

This leads us to discuss a better way - a “wellness medicine” mindset or health model. It dares ask different questions, such as:

• How well do you want to be?
• How much dentistry do you want after age 60?
• How many broken teeth do you want?
• How many root canals do you want?
• What if something could be done now that would prevent broken teeth, treat your teeth more conservatively, restore your peace-of-mind, and keep Murphy at bay – forever!? Oh, and make the teeth strong, attractive, and like well - normal teeth?

This kind of thinking leads you to make different decisions about how and when you proceed with your dental care. It also ultimately predicts whether you will enjoy a lifetime of healthy, attractive, strong and durable teeth.

Cracked Tooth Syndrome
Whether a tooth hurts or not depends on the depth and severity of the crack. When a tooth hurts without actually breaking apart it is called “Cracked Tooth Syndrome.” This is most often characterized by a tooth that hurts during biting pressure, and which immediately stops hurting when the bite pressure is released.

Cracked Tooth Syndrome is defined as an incomplete fracture of dental tooth structures. It is usually associated with a sharp pain during chewing. During chewing functions and biting pressures, a small, sometimes undetectable, crack or fracture may allow broken tooth sections to flex or move apart slightly. This causes immediate tooth sensitivity and pain.

As the insult continues and the tooth nerve becomes more inflamed, the cracking tooth problem can progress to a full-blown toothache, pulp death, necrosis and infection (abscess). When the nerve of a tooth dies it now requires a root canal procedure or tooth extraction. What started as an innocent and innocuous little craze line adjacent to a well-meaning silver mercury filling is now the reason for a very costly and often uncomfortable outcome.

It should be remembered that cracks and fracturing can be present in tooth structure without the production of pain or other symptoms. Whether this is the case or not for your teeth, it highlights the importance of proactive “wellness” diagnosis and treatment planning. Since we know what happens to teeth long-term that have silver mercury fillings, and since you want to avoid costly and painful problems, it makes sense to restore the affected teeth to an optimal condition of health and wellness with modern techniques and modern dental materials – BEFORE they actually break apart!

No longer is it okay to explain it away with an “if it doesn’t hurt and it isn’t broke – it must be okay” excuse! No longer should it be acceptable for a dentist to know what is best and not offer better solutions. The least expensive dentistry is dentistry that avoids the loss of tooth structure. This is because it costs more to fix it later – cost in terms of money, root canals, complex restorations, lost teeth, lost function, lost dignity, unattractive worn smiles, painful chewing, and so forth. Why chance it?

Cracks in Teeth Don’t Heal
There is no blood supply or biological mechanism that allows for cracked tooth structure to heal or knit together (like a broken bone). It will never heal and be restored to its previous normal strength on its own. Never! Never! Never! It is a structural object that once cracked is forever compromised - unless it is restored with a durable dental restoration which will hold it together and restore it’s structural integrity. Therefore, appropriate treatment for a broken tooth must take into consideration the requirements for reinforcing cracked tooth structure, and to do it in a way that it can hold up in the stressful and dynamic environment of the mouth.

Anticipating future problems with a healthy “wellness” mindset allows for budgeting the dental dollars and preventing the inevitable consequences that occur as silver mercury fillings degrade, expand, and weaken the tooth. In the end, the objective of therapy is to create a stable solution that can withstand any and all forces that might be placed upon it, and which will allow it to function in comfort for a long duration, and which will allow a person to do so in a sound financial way – no budget surprises! Modern adhesive dentistry techniques practiced by well-trained and experienced dentists assure you of the best possible outcome in both durability and pleasing attractive teeth.

Cracked Teeth are predictable – not planned!
Cracked teeth are like a ticking time-bomb. If you know it is there, why let it keep ticking? Cracks propagate and deepen on their own timetable. Since the problems begin rather innocently and quietly, it is easy to ignore them until it catches your attention with a sudden twinge or jolt. By then it’s too late - you are holding the side of your tooth in your hand, or wondering what you ate that was crunchy. This is when you will know you didn’t plan well. Business activities, vacations, trips out of town, or life in general are put on hold while you frantically try to fix a problem you could have dealt with much earlier upstream. If only you would have been told! If only you would have listened! Warning: Don’t eat the peanuts on the outbound flight!

What To Do
If you have cracked teeth, old fillings, or you want to increase your peace-of-mind and confidence, you may schedule a consultation with Dr. Ostler at the Center for Dental Health. He will help you with a customized personal plan for avoiding the problems of broken teeth and enjoying comfortable attractive teeth for a lifetime. Budgeting your time and your dollars with a well thought out plan will be a wise investment in your future, your business, your health, and in your peace-of-mind.

You may read other timely and informative reports in this series at www.MakeMeSmile.info, or www.CenterForDentalHealth.com.

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