Tag Archives: Amalgam

“My Fillings Don’t Last Forever? Oh My Gosh!”

“Thank you” Lori Moller who inspired this article during a recent visit to our office. Lori provided her unbiased opinion stating she believed her dental fillings lasted a lifetime. This is such a big misconception in dentistry. Lori granted an in-depth telephone interview to provide further insights as to why she felt her fillings would last throughout her entire life.


  1. Fillings last a lifetime; true or false?
  2. How long do dental fillings last?
  3. All fillings last about the same time; true or false?
  4. People’s mouths don’t influence how long fillings last; true or false?
  5. All dentists achieve the same quality fillings; true or false?
  6. Old fillings have to fracture before they need replacing: true or false?
  7. Fillings don’t get decay around them; true or false?

(Answers: found throughout the article.)

Most people are not very enlightened about their dental fillings, and have the same notion Lori did. Most of us receive fillings when we’re children and dentists seldom volunteer an explanation of how long these fillings should last. A comedian once joked asking Jimmy Carter what he thought about pregnant Scandinavian Nuns, to which he replied, I don’t think about pregnant Scandinavian Nuns. The same aspect applies to dental fillings. We just don’t think about fillings. Consequently, we grow up without any facts or expectations regarding our fillings, we do not discuss this in school, nor socially, so until a dentist examines our fillings and surprisingly tells us they need to be replaced, we assume they last indefinitely.

During routine discussions with patients on a daily basis, it is clearly evident a large majority of patients believe dental fillings placed during childhood last for the remainder of their lives. When you consider our mouths are constantly moist, 98.6 degrees and full of millions of bacteria, it is as the Listerine commercial used to say, “a battle ground”.

In fact, there are more than 100 species of bacteria, hundreds of species of fungi, protozoa, and viruses that reside in our mouths. Further, microbiologists estimate there are an additional 500 living, breathing organisms inhabiting our mouths. Our mouths contain more bacteria than the entire world’s population, while our bodies house approximately one trillion bacteria.   Bacteria get into our teeth because of many imperfections — the grooves in the top of our teeth — despite the defense of our saliva, immune system, brushing and fluoride. A cavity follows. Decay must be removed and is accomplished by drilling and creating what is termed a “cavity prep”.   The cavity prep is now filled, traditionally by “amalgam” (silver filling) or more recently by “composite” (white fillings), to create a new surface that is impervious to future decay, but realistically not forever. So, how long do fillings last?

Think about car tires and answer the question, how long do tires last? The answer depends on many factors including the quality of the tires, how much you drive in a year, how heavy the vehicle, how many people typically ride in the vehicle, conservative or aggressive driving habits, damaging the tires, whether the tires are properly aligned, and even the geographical climate of where you drive the vehicle.

Dental fillings are also affected by many variables. These include thermal changes that affect the tooth and filling differently, the size of the filling, how big the filling is relative to the tooth, type of food and liquid the person ingests (i.e. sodas, chewing ice or hard candy), heavy biting force, acid reflux, grinding of teeth at night, clenching teeth during the day, taking medications, aggressive strains of bacteria, and strength of person’s immune system.  Fillings, similar to the tire analogy, can last for only a few years or for decades depending on the abuse they must withstand.

For example, a large man with strong jaw muscles, that clenches in the day and grinds at night, with acid reflux that is exacerbated by a poor diet of acid-rich foods, sodas and many medications cannot expect fillings, especially large fillings, to last anywhere near the norm of 10-15 years.

Fillings more obviously require replacement when a filling breaks fillingsout of the tooth or the tooth breaks around the filling leaving a gap and exposing “dentin”, which is the layer of soft tooth structure beneath the enamel very vulnerable to bacteria.   Fillings less obviously require replacement as they chronically disintegrate from years of physical deterioration at the junction of the filling and tooth, allowing bacteria to penetrate down the sides of the fillinginto the tooth, causing “recurring decay”. Bacteria once inside the tooth cause decay by producing acid that destroys tooth structure. Another common cause of recurring decay is an old philosophy of placing a small filling in the middle of a tooth surface with many grooves that were not all included in the cavity prep (known today as “extension for prevention”), nor were the grooves sealed, and resulting in these grooves eventually experiencing recurrent decay. Thus fillings or teeth do not have to break in order to replace a filling.

In SUMMARY, fillings don’t last a lifetime. Fillings last 10-15 years based upon historical average. The best time to replace fillings is once they demonstrate “marginal” breakdown (gaps between the filling and tooth) so that recurrent decay is kept at a minimum.

It is important to realize all dental treatment and fillings are performed to eliminate bacteria and prevent the future access of bacteria. Therefore, the dentist should work with microscopic glasses to magnify the tooth and let him see details associated with placing the filling into the tooth and polishing the filling so well that bacteria cannot get under it.

Dental fillings will typically be placed during childhood and replaced three times in a person’s life. Fillings initially placed during ages 6-13 will be replaced in a person’s 30-40’s, again in a person’s 50-60’s, and again in a person’s 70-80’s. Dental fillings are amazing.   Rejoice in the fact that dental fillings in today’s technology are white and very natural looking, very different from the unattractive result of a mouth full of silver fillings that was experienced years ago. Realize that decay happens, and fillings need to be replaced multiple times in your life. This will avoid the surprise felt by Lori and many other patients.