Hard Facts on Soft Teeth

Over my many years in private practice as a dentist, I’ve heard numerous things. Many times patients will say:

I only have these cavities because I have soft teeth.

On a similar note, I’ve talked to many dentists who have either said or written:

There’s no such thing as soft teeth.

Well, I’m here to tell you that, generally speaking, both of the above comments are correct. You won’t hear other dentists saying this. Let’s look at the whole “soft teeth” issue in greater detail to understand this apparent contradiction.

Soft Teeth is Not a Valid Dental Term

The term “soft teeth” is not a true medical or dental term the way “Type II Diabetes” and “COPD” are. If I pick up one of my textbooks from dental school, there is no mention of the term “soft teeth.” So that’s why many dentists dispute the notion.

decayed teethphoto - not because they were soft

These teeth decayed not because they were “soft” – but because of lack of proper hygiene.

Dentists will also discard this notion because many patients will try to use the “soft teeth excuse” for their cavities when in reality it is due to oral hygiene and/or sugar intake. If you drink 5 cans of Mountain Dew a day and brush your teeth once a week, don’t try to claim your cavities are from your teeth being soft!

But Some Teeth Can Be “Softer” Than Others

So, even though the dental term soft teeth does not exist, some teeth are more susceptible to developing decay than others. Let’s look at one specific example:

soft teeth photo due to trauma leading to cavities

This patient’s left tooth is weaker due to a history of trauma and infection when it was developing. The brown area is much more likely to get a cavity.

In the above case, the tooth on the patient’s left is weaker and “softer” than the right one. It is intrinsically weaker.

How did this happen? When the patient was younger, he suffered trauma which damaged a baby tooth. The trauma led to an infection of the baby tooth which then traveled directly up to affect the developing adult tooth. The tooth came in like this – and is clearly weaker than the one on the right.

So What Makes Teeth “Soft?”

A tooth can be “soft” if some unusual event occurs to disrupt normal development. The development of a tooth is a complex and coordinated process any many things can disrupt it. Examples include:

  1. Trauma, dental decay, or other factor leading to an infection of the baby tooth preceding the adult tooth.
  2. Fever, even for a short period of time.
  3. Malnutrition leading to vitamin deficiencies.
  4. Hormonal imbalances.
  5. Certain rare genetic conditions.
  6. Systemic consumption of fluoride at extremely high levels (> 5 ppm).
  7. And other factors (usually quite rare).

The key point here is that for any of these events to have an effect on the softness/hardness of the teeth – the disturbance must occur WHILE the teeth are developing.

Here is another photo of teeth which are weaker due to an unusual event which occurred during development:

teeth with fluorosis photo showing soft teeth

These teeth are “softer” or higher risk for decay due to excessive fluoride consumption when the teeth were developing.

The above photo illustrates one example of what can make teeth weaker or “soft.” In this case, an unusual occurrence (excessive systemic fluoride consumption) during tooth development led to mottled and pitted enamel – which is much more likely to develop decay.

The Hard Facts

So, many of you now might be wondering: am I getting all these cavities because I have “soft” teeth?

The answer is: probably not.

Why, you may ask?

  • First, as mentioned above, for teeth to be “soft” or weaker, something needs to have happened when the teeth were developing. Except for wisdom teeth, your teeth are done developing around age 14. So, unless one of the above things occurred before age 14, your teeth are not intrinsically weaker.
  • Second, in nearly all cases, your teeth will appear different. The teeth may have brown spots, chalky spots, banding, or other unusual appearances. If your teeth look normal – and your dentist has never mentioned any unusual findings – your teeth are most likely not “soft.”

Many people incorrectly believe that certain events can cause their teeth to become “soft.”  These include pregnancy, breastfeeding, a diagnosis of diabetes as an adult, new allergies, and many other occurrences.

So, if you’re developing cavities, they are most likely from diet and/or hygiene. Developing “soft teeth” later in life is a myth.

What Does a Cavity Under a Crown Look Like?

As this blog approaches nearly 3 years of age and well over 150,000 views, I am able to see what the more popular dental topics are out there. Currently, the fourth most popular post on this site, clocking in with a little more than 19,000 views (as of July 2015), is Dental MythBuster #9: You can’t get a cavity under a crown.

In analyzing what people search for online, many readers – hundreds that is – searched for some variation of: what does a cavity under a dental crown look like?

I had just finished compiling this information when a long time patient of mine – one who I had been telling for several months now about decay under one of her crowns – called to finally schedule her extraction.

Photos and X-rays of Cavities Under a Crown

In this particular case, the decay was so deep that her only option was extraction (see below for why extraction was her only options). Below is a bitewing x-ray:

dental bitewing x-ray showing decay under a crown

The x-ray shows the definite shadow of decay underneath a crown.

I had first diagnosed this nearly a year ago primarily based on the x-ray. In this area of the mouth – the last tooth on the lower left – the cheek drapes up against the tooth – making it very difficult to see – and very difficult to brush!.

I then removed the tooth. And no, I did not put my knee on her chest! The decay was unmistakable. Upon completing the procedure and having the patient go home, the first thing I thought was: “this will make a great photo for my blog!” So here it is:

high quality detailed photo of extracted tooth with decayed cavity under a dental crown

The extracted tooth in all its glory. If you dare, you can click on it to see a larger version!

You can clearly see the decay on this crown when it is out of the mouth. However, when it was in her mouth, it was nearly impossible to see. It could only be “felt” with a dental instrument. But the x-ray showed it.

Why was the tooth extracted?

If you get decay underneath a crown, it doesn’t always mean that the tooth has to be extracted. Before I explain why this was extracted, let’s look at one where the tooth was able to be fixed:

high quality photo of a cavity under an incisor crown

The decay underneath this crown was predictably fixed with a new crown.

The tooth directly above could be saved because the decay was easily accessible and only extended slightly underneath the gum tissue. The tooth had already had a root canal.

For the first tooth, the decay extended deep underneath the gum tissue and went into the furcation (the furcation is where the two roots of two-rooted tooth meet). No amount of modern dental procedures could have saved the tooth. So we extracted it and placed a dental implant.

Please note that I have greatly simplified the criteria for when a tooth can be saved vs. extracted. There are dozens of other factors – all beyond the scope of this post.

So, to summarize:

  • You can get decay or cavities underneath a crown.
  • The extent and location of the decay as well as other factors will dictate the treatment needed to correct the problem.

As always, your dentist should answer all your questions. If he/she doesn’t, it’s time to look for a new one.

Dental MythBuster #13: A Dental Filling Will Last Forever

Fortunately, this dental myth does not come up very often. When it does, the myth usually comes up when I have to deliver news along the lines of “I have a concern about one of your fillings.”

Most patients understand that dental fillings are usually not lifelong permanent solutions. But some patients don’t. Like many other medical devices and appliances, fillings don’t last forever.

Problems with Dental Fillings

There are all types of problems that can occur with dental filings. Below are some examples:

broken mercury amalgam filling in a tooth

A broken silver amalgam filling. This will need to be replaced.

The tooth above shows two premolar teeth, both with amalgam fillings. One of the fillings has cracked. There are many reasons why it cracked – but they go beyond the scope of this post. However, to summarize, after being chewed upon several hundred thousand times, it has finally failed.

high quality photo of broken lower molar tooth with a filling

Here, both filling and tooth broke!

In this photo, a large portion of both tooth and filling broke. In this particular case, the filling had been there for over 20 years, but the remaining tooth structure was so weak it finally gave out. In this case, this patient needed a crown.

In addition to the above two examples, dental fillings can fail for many other reasons. And many will fail due to a combination of multiple factors.

What other medical appliances last a lifetime?

On occasion, I will come across a patient who is particularly disturbed that one of their fillings done during the Clinton presidency needs to be replaced. I will often politely respond by referencing other medical appliances:

cardiac pacemaker is like a filling and can last seven years

On average a pacemaker lasts seven years.

What do the above 3 devices all have in common? These are all manmade devices designed to replace or repair damaged or missing human tissue. And that is exactly what a filling is.

When I mention these examples, most patients begin to understand fillings typically have a finite lifespan. And then the myth is busted…

How Long Should a Filling Last?

This is difficult to answer since there are so many factors at play. I’ve seen fillings last over 40 years while others fail within 1 to 2 years. The factors can include:

  • Type of material (silver amalgam vs. resin composite).
  • Location in the mouth.
  • Oral hygiene.
  • Sugar intake.
  • Occlusion (how the teeth come together).
  • Skill level and attention to detail of the dentist who placed it.

So, while occasionally a filling can last a lifetime, that is not the norm. Just like nearly all other medical appliances and devices, they can and do wear out. It is a myth that all fillings will last forever.

Dental MythBuster #12 – I can’t have a cavity because there is no hole in my tooth!

This Dental MythBuster is slightly unfair, as it relies upon the slang term cavity that has been used for decades. However, it is still a myth, and like all dental myths, this myth needs to be identified and busted!

Let’s start by looking at a photo:

high res photo showing teeth with dental decay but not cavities

Photo showing decay on front teeth but no “cavities” present.

If you look at the above photo, everyone would agree that something is not right. The brown/grey areas where the teeth touch one another look awfully suspicious. When I informed this patient that she needed fillings with those teeth, she looked at me perplexed and said “Why… I can’t feel any cavities there?!?”

I hear this dental myth about once per week in my office. Once I show either an x-ray or photo of the cavity, they understand immediately. Wouldn’t you if you saw the above photo?

Cavities, Caries, and Decay

Part of the reason why this dental myth exists is because there is some confusion and misuse of various dental terms. And we dentists are part of the problem! Let’s look at definitions:

Dental Caries – also known as dental decay, this is an infectious disease leading to the progressive destruction of tooth structure. This is seen in the photo above.

Dental Cavities – a carious lesion or hole in a tooth. Although this term is used quite often, it is generally considered to be a slang term.

So, what does an actual dental cavity look like? See below:

photo showing teeth cavities visible in the actual mouth

Two cavities present. In this case, there are actual holes in the teeth!

In the above photo, you can see actual holes in the teeth. These are areas of dental decay that have progressed to the point where the tooth surface actually collapsed in, creating a cavity. This patient was actually able to feel and see the cavities.

Another Dental Myth Goes Down

So far, we’ve seen two photos: one showing decay without holes and one showing decay with holes.

In both cases, the patients required fillings and/or other work to restore. I don’t think anyone would disagree with that.

So, let’s dispel this myth with this simple statement:

Dental cavities can be present with our without actual holes in your teeth. You don’t need an actual hole in your tooth to need a filling.

So if your dentist tells you that you have decay (or cavities) and you can’t see or feel a hole, it doesn’t mean there is no cavity. It is definitely there. Ask your dentist to show it to you on an x-ray or have him/her take a photograph of it. I do it all the time.

I hope you enjoyed this post. I’m already working on Dental MythBuster #13!