Would my dentist think my teeth look healthy?

Old fillings show signs of wear

You look at your teeth in the mirror every day when you brush them, and they look “fine” to you. Sure, there are some old fillings, but nothing hurts, so it must be okay…right? Interestingly, dental decay is usually completely painless. If something hurts, the problem may be bigger than you think.

Let me lead you through what your dentist will be looking for at your next dental check-up. In our office, dental check-ups are done with magnifying lenses attached to our glasses, along with a bright headlight. This allows us to see teeth magnified large enough to easily see imperfections. As well, we use digital photography as with this patient. This enables us to make an image as large as we need to in order to diagnose any potential problems.

What does a dentist look for with silver fillings to see if they should be changed?

The patient in this photo has no pain in her teeth. The silver (amalgam/mercury) fillings are quite old, perhaps 25 years or more. Regarding silver fillings—the tooth around the filling, if healthy, should be tooth-colored, not gray/green/black. As well, the edges of the fillings should meet the surrounding tooth smoothly with no visible gaps on photographs. Lastly, the filling surfaces should be smooth and consistently shiny with no signs of corrosion. Knowing this, now look at the teeth in this photograph and decide if the fillings are still good, or if they should be replaced. Each one of them exhibits the problems mentioned, and in fact when they were removed there was significant decay (cavity) under each one, none of which could be seen on the x-ray!

What does a dentist look for with tooth-colored fillings to see if they should be replaced?

Now look at the tooth-colored fillings, which are about 10 years old. They should also be smooth, fit without gaps at the edges where they meet the teeth, and there should not be any staining where filling meets tooth. Where there is stain, there is bacteria and mold seeping between the filling edge and the tooth…gross! Do you see a problem with these fillings? Under each one was also decay, and it was completely painless.

How long should fillings last?

This honestly depends upon the size of the filling, the depth of the filling, the type of material used, the eating habits of the patient, the oral hygiene habits of the patient, the level of bad bacteria living in a patient’s mouth…the short answer is there is no one answer to suit everyone! There is a range of lifespan for any type of filling, which is longer in a smaller, more shallow filling which is not in a back tooth and not under heavy stress. Many of the patients we see have fillings way larger than the condition of the tooth calls for, and this leads to early breakdown of the filling, along the lines of 2-5 years. I have yet to remove a silver filling more than 10-15 years old and NOT found any decay…so that gives an idea that most fillings stay in teeth longer than they should.

How can I make my fillings last longer?

The material used has to suit the purpose. A typical “white” or “tooth-colored” filling shouldn’t take up more than 50% of the tooth; if that much tooth needs replacement a stronger material should be used. This would typically be porcelain/ceramic or a fairly new material in dentistry, zirconia, which is extremely durable. These types of materials come with a higher price tag because usually a dental laboratory is involved in constructing them. However, we don’t see the same kind of breakdown where the filling material and tooth meet because the material used is harder.

Another important factor in the lifespan of filling material is the patient’s bite. If the teeth are straight and the bite is even on both sides, any filling material used will last longer than if the teeth are crooked or there is bite malfunction (think clicking, popping jaws, or worn-down teeth). Almost any materials used in these situations will faily more quickly; sometimes the best insurance for longevity is making the bite right first, then replacing the fillings.

Lastly is home care. Dentists and dental hygienists nag about flossing…but with good reason. We also understand that not a lot of patients actually do floss daily, and even when they do, it is often not done properly to give the best benefits. Here is an excellent tutorial about flossing…but in our office we recommend a high-quality electric toothbrush (we like Sonicare) and also a Waterpik (in addition to or…gasp…instead of flossing) to get between the teeth and flush out all the debris that sticks to your teeth.

Next time you go to your dentist, ask how dental decay and failing fillings are diagnosed in their office, and what choices of materials you have for replacement. We are also happy to ask any questions you may have…feel free to post them below!