That’s a great question! The lifespan of a filling depends on several different factors, some of which are within your control and some that are not. We are not the type of dental office that recommends replacement of all of your old fillings. Our conservative philosophy of dentistry means that we only prescribe treatment when there is verifiable breakdown of the existing dental work. Typically, this is visible either in a close-up photo of the tooth or on the yearly dental x-rays.
What Causes Breakdown of Fillings?
Fillings do suffer from wear and tear of temperature changes and chewing forces. Aside from a general, slow deterioration, there are a few conditions that lead to rapid breakdown of a dental filling.
An Additional Cavity
The most common reason that we have to replace fillings is the development of a new cavity on the same tooth. Typically, this occurs at the edge of the filling, and we call it “recurrent decay”. We have found that many people are surprised to learn that they can get a cavity on a tooth that already has a filling. In fact, a tooth with an existing filling is more likely to get a new cavity than a tooth that has never been filled. Having prior decay on a tooth makes it more likely to get additional decay.
Anytime plaque remains on the tooth surface, the bacteria that it contains eat sugar and produce acids. These acids weaken enamel and soften it, allowing the bacteria to work their way into the tooth. It is easier for bacteria to penetrate the area where a filling meets the enamel than it is for it to penetrate solid enamel.
Under heavy forces, a filling can crack, or the tooth structure around the filling can crack. Usually, a fracture develops as the result of consistent heavy forces over a prolonged period of time (i.e. nighttime clenching and/or grinding). Sometimes it occurs in a single incident, such as biting on a bone or foreign object in your food. We can also predispose our teeth and fillings to crack by drastic thermal changes. This is due to the harsh effect of drinking ice-cold water and then following that with a bite of hot food. This can cause a crack in the same way that pouring hot water on your frozen windshield would.
Erosion is the slow, gradual wearing away of tooth structure by exposing it to strong acids. We see erosion as a result of frequent vomiting, severe acid reflux or GERD, or consistent intake of acidic foods & beverages. Erosion may wear down the filling, the tooth structure surrounding the filling, or both. The process of erosion deteriorates the bond between the filling and the tooth, opening up small gaps for bacteria to penetrate.
What is the Dentist’s Role in a Filling’s Lifespan?
The dentist does carry the responsibility of doing the filling correctly. By doing the filling correctly, we mean that the dentist uses the right materials and places it into the tooth with the right technique. This also includes adjusting the new filling to the proper contour and bite relationship, and then polishing it well.
- Use High Quality Materials – Different filling materials have different bond strengths with tooth structure. We use an American-made composite resin that consistently tests at the highest bond strength.
- Use Excellent Technique – Understanding how to place the filling into the tooth also increases its long-term success. Fillings cannot be contaminated by saliva or any other moisture during the placement.
- Adjust Contours and Bite Appropriately – The way that this step contributes to long-term success is by protecting the tooth from inappropriate chewing forces. This step is important to prevent fractures!
- Polish – Polishing the new filling material reduces its likelihood of attracting plaque buildup. Plaque likes to stick to rough or uneven surfaces, not shiny smooth ones. Because plaque leads to cavities, reducing plaque lowers the risk of getting a new cavity.
What is My Role in a Filling’s Lifespan?
Once the filling is in your mouth, the dentist’s job is complete. Now it is your turn to take care of things! Here is how you can lengthen the lifespan of your fillings.
- Prevent Cavities – Practice great oral hygiene by brushing twice daily and flossing every night before bed. Add a cavity-fighting mouthwash that contains fluoride. Make sure you keep up with consistent professional teeth cleanings to remove plaque buildup from any areas you might miss. Follow through with recommendations for preventive dental options to keep your teeth as strong and healthy as possible.
- Guard against Heavy Forces – If you are putting heavy forces on your teeth with nighttime clenching and/or grinding, we will be able to tell. If we see evidence of this (uncontrollable) habit, we will recommend a professional nightguard that covers the teeth to protect them from these fracture-producing forces. Wearing it nightly will give you a higher success rate on your fillings.
- Watch the pH of Your Mouth – To guard against erosion, you should be careful with the pH in your mouth. Patients who suffer from medical conditions that bring stomach acid up into the mouth should seek treatment from their primary care physicians. Avoid acidic drinks like sodas, sports drinks, and fruit juices. Stay away from strong acids like lemons and apple cider vinegar (commonly touted as effective “cleanses”).
More Questions about Fillings?
Call 972-347-1145 today to schedule a consultation with Dr. Jill and Dr. Cara. If you need fillings or want your existing fillings checked, we can provide the thorough evaluation and any recommended treatment that you may need.