How can you tell if a filling is leaking?

This blog post will address the topic, “how can you tell if a filling is leaking?” and cover topics like do cavity fillings need to be replaced, how to know if your fillings need replacement, what are the different types of filling materials, after how long the cavity fillings need to be replaced, why do cavity fillings leak and precautions to be taken after filling to prevent filling leakage.

How Can You Tell If A Filling Is Leaking?

You can tell if a filling is leaking by noticing some significant signs and symptoms such as darkening of your filled tooth, or feeling of pressure while biting, or pain while biting, or a hole in the filled tooth felt through your tongue, or sensitivity felt on eating or drinking something too hot or cold.

If you notice any of the above mentioned signs or symptoms, you must immediately consult your dentist.

Ignoring filling leakage may result in reappearance of cavities and tooth infection and you might have to undergo root canal treatment.

Do Cavity Fillings Need To Be Replaced?

Yes, cavity fillings need to be replaced once it falls out or wears out leaving the cavity exposed to bacterial infiltration.

Tooth cavity filling materials are constantly subjected to biting force, or may be stress from teeth clenching, wearing them out slowly and slowly, ultimately leading to their fall out, cracking or chipping off.

Once fillings are worn out, replacement is needed to prevent bacterial invasion and cavity reappearance.

How Do I Know If A Filling Needs To Be Replaced?

Your filling needs to be replaced when it :

  1. wears out and falls off, or 
  1. when the filled tooth starts experiencing pain and sensitivity, or 
  1. when the filled tooth gets injured or fractured, or 
  1. when the filling material gets darkened
  1. Tooth with filling hurts on drinking hot or cold beverages
  1. Filling hangs out causing difficulty in chewing and biting

In any of the above cases, a cavity filling needs replacement and you must visit your dentist to get your filling examined.

What Are The Different Types Of Filling Materials?

Dental filling, as the name suggests, is the use of various materials to fill the hole in the teeth called cavities. 

Materials used to fill the cavities are referred to as filling materials and the process is known as dental filling.

Variety of materials are used for filling. Some of them are listed below:

  • Gold fillings 
  • Porcelain 
  • Silver amalgam  
  • Tooth-colored materials called composite resin fillings
  • Glass Ionomer

Several factors that need consideration while choosing the best filling material for yourself are:

  • Where is the decay located?
  • How much decay has involved the tooth?
  • If the roots are involved?
  • Amount you can bear for a filling?
  • Recommendation of the dentist after full examination and X-Ray

After taking all the above points in consideration, you can choose the best filling material for yourself that will have maximum efficacy and minimum discomfort.

How Long Do Fillings Need Replacing?

The replacement depends on the type of filling material along with the oral hygiene of the individual, their eating habits and also if they have a habit of teeth grinding.

However, according to studies, composites can last for an average duration of 7-8 years, amalgam and ceramics may last for almost 15-20 years and glass ionomers may only last for an average duration of 5 years.


Composite fillings closely match the tooth colour and therefore are most commonly used for anterior(front) teeth.

Cavity preparation involves removal of less tooth structure as compared to amalgam fillings.

Lasts for at most 5 years, is less durable and also bears less strength compared to amalgam fillings which last for more than 10-15 years.


Porcelain is most commonly used in preparing ceramics with stain resistance more than composites.

Lasts three times more than the composites, for at least 15 years.

Being tooth colored and also more durable makes it as expensive as gold.

Glass Ionomers

Prepared from acrylic and glass material of specific type, glass ionomers are very weak filling material.

Being weak, it is avoided from use on biting surfaces and is common for filling the teeth of young children.

Fluoride release is common and therefore protects the tooth from developing cavities and undergoing decay.

Old generation glass ionomer fillings lasted for less than 5 years but new generations of these fillings lasts more.

Cost is comparable to composites.

Why Do Cavity Fillings Leak?

There can be multiple reasons behind cavity fillings leakage:

Fall out just after filling

Eating hard or sticky food just after filling may cause the filling to fall out and leak. Such leaking fillings need to be replaced to keep the tooth cavity-free.

Too hot or too cold drinks and foods might cause thermal expansion and contraction of the filling material resulting in fall out or crack and finally leakage.

Inadequate sealing and microleakage

Sealing the cavity properly is essential to prevent microleakage and bacterial invasion inside the cavity.

Improper sealing makes it necessary to replace the filling and get a new one to prevent microleakage.

Chipped off or fractured filling

Teeth grinding habits are common to result in chipped-off or worn out or fractured filling resulting in filling material replacement.

Teeth grinding habits may significantly reduce the life of filling materials and dentists may recommend a mouth guard.

Excessive Bite Force

Sometimes, maybe accidentally or while eating, excessive biting force may rip off your filling material and cause it to leak.

It is recommended to take precautions while eating anything hard and the filling must be avoided in doing so.

Precautions To Be Taken After Filling To Prevent Filling Leakage

To prevent your filling from damage and leakage and to make your tooth stop hurting after a filling, you may do the following:

  1. Take over-the-counter painkillers – Non-steroidal anti-inflammatory drugs are mostly preferred such as paracetamol or ibuprofen.
  1. Cautious Chewing – Chew on the opposite side of the new filling with minimum pressure
  1. Eating soft foods –  Hard food puts a lot of pressure on the teeth surface causing discomfort to increase.
  1. Avoid sticky foods – Do not eat foods that are sticky in nature as it may stick to your new filling and dislodge it. This mostly happens with amalgam fillings.
  1. Eat slowly –  This will put less pressure on the tooth and relieve the discomfort.
  1. Avoid too hot or cold foods and drinks – Do not eat or drink anything that might trigger tooth sensitivity. Too hot, too cold or sugar rich foods and drinks must be kept away from your palate.
  1. Gentle brushing with short strokes – Make sure you do not brush vigorously or with extra force.
  1. Cautious Flossing –  after a filling, flossing must be done gently using an extra-thin floss. Be cautious of not doing it forcefully and extra cautious when the filling is on the tooth edge.
  1. Desensitising toothpaste –  will make your tooth not hurt after filling.


This blog post addressed the topic, “how can you tell if a filling is leaking?”. We understood if cavity fillings need to be replaced, how to know if your fillings need replacement, what are the different types of filling materials and after how long the cavity fillings need to be replaced. The article outlined reasons for leakage of cavity fillings and precautions to be taken after filling to prevent filling leakage.

FREQUENTLY ASKED QUESTIONS (FAQs): How Can You Tell If A Filling Is Leaking

What happens when a filling is leaking?

When the filling is leaking, it indicates a gap between the filling and the tooth. The inadequate seal allows food, bacteria and saliva to enter, resulting in a breeding ground for cavities causing bacteria, leading to reappearance of cavities and tooth infection.

The symptoms of pain, sensitivity and pressure may be felt again in the filled tooth. Ignorance may lead to severe tooth infection that may require a root canal treatment or even extraction.

What does a leaking filling taste like?

Leaking filling may taste like metal, giving your mouth a metallic taste. Old silver or amalgam fillings may leak out leaving metallic taste on your taste buds.

Consult your dentist as soon as you notice any metallic taste.

Can a root canal filling leak?

Yes, a root canal filling may leak if the root canal fails.

According to a published study, root canal treatment has a success rate of 86-98%.

The same study enumerates some common factors responsible for the failure of root canal:

  • Improper or poor access cavity design.
  • Incomplete removal of the infected pulp tissue.
  • Inability to remove the infected remnants and debris.
  • Improper or insufficient disinfection of the root canal.
  • Missing an extra or accessory-infected root canal, mostly when there are multiple canals present.
  • Inadequate filling or over-filling of the canal.
  • Inadequate seal that allows micro-leakage and bacterial infection to penetrate the tooth canal again.
  • Crown breakage that allows the filling material to wear off eventually and bacterial penetration again in the cavity.
  • Instrumentation errors like perforation or ledges.

The failure of the root canal can occur at any time, may be soon after the treatment or may be years after.

How Do You Know If A Root Canal Has Failed And Is Leaking?

Root canal failure may produce symptoms similar to that you experienced before root canal treatment or may not produce any symptoms at all.

However, the common symptoms of failed root canal treatment are:

  • Pain
  • Sensitivity
  • Swelling in and around tooth 
  • Pus discharge from the tooth
  • Discoloration of the tooth
  • Abscess
  • X-ray irregularities with no above mentioned symptoms

How long after a root canal should you get a permanent filling?

In not more than 6 weeks, you will be able to get a permanent filling done.

It is advised to not delay your appointment for permanent filling as it may weaken your temporary filling, cause its fall out and reinfect the canal leading to root canal failure.

Other FAQs about Teeth Filling that you may be interested in.

How can I make my tooth stop hurting after a filling?

Can fillings last 40 years?

Can composite fillings last 20 years?


Dental Fillings Are Durable But Don’t Last Forever – Colgate

How Long Do Fillings Last? Types, Prevention & More

What Is a Filling? Colgate

Dental Health and Tooth Fillings. (2019)

Chewing Tips After A Filling. Colgate

Root canal treatment. (2019)

Care After Root Canal Treatment Visits

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