Do cavity fillings need to be replaced?

This blog post will address the topic, “do cavity fillings need to be replaced” and cover topics like what are the different types of filling materials, after how long the cavity fillings need to be replaced, why do cavity fillings need replacement and precautions to take for your fillings to last longer.

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.


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.

After How Long The Cavity Fillings Need To Be Replaced?

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 color 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 last more.

Cost is comparable to composites.

Why Do Cavity Fillings Need Replacement?

There can be multiple reasons behind replacing cavity fillings:

Fall out just after filling

Eating hard or sticky food just after filling may cause the filling to fall out and needs 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.

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, may be accidentally or while eating, excessive biting force may rip off your filling material.

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

Precautions To Take For Your Fillings To Last Longer

How Long Should I Wait To Eat After Getting My Filling Done?

It is a common question in every patient’s mind and the answer is not that simple. It depends on the following factors:

Filling Type

Amalgam filling takes almost 24 hours to harden and therefore you can only start eating after 24 hours.

Composite hardens as soon as you leave the dental chair and therefore you can eat once the local anesthetic wears off.

Local anesthetic

Local anesthetic applied during the filling process makes the entire procedure pain free as it numbs the surrounding soft tissues.

The numbness takes almost 1 to 3 hours to go away and therefore you must eat after the numbness has subsided.

If you eat when your mouth is still numb, the risk of chewing and damaging your tongue, cheeks and lips increases.

Hence, it is advised to eat only after the numbness in your mouth disappears.

Discomfort After Filling

It is quite normal to face some discomfort like pain and pressure upon biting after filling or soreness in the gums.

Such discomfort may disturb your mood and hasten your desire to eat.

Over the counter pain killer and salt water rinse will help in comforting you.

Sensitivity After Filling

Eating or drinking too hot or cold might cause sensitivity and interrupt your happy eating hours. 

This is temporary and will subside in coming weeks after filling and till then it is advised to avoid too hot or cold food or drinks and also foods that are causing sensitivity.

Biting Difficulty After Filling

Sometimes, the trimming and polishing part is not done accurately, which leaves the filling too high, causing pain and pressure on biting.

This can be corrected by the dentist in no time and will help you to quickly come out of discomfort.

How To Eat After A Filling Without Damaging It?

After a filling, you might feel some discomfort and need to follow the following to get some relief:

  1. Chew on the opposite side of the new filling with minimum pressure
  1. Eat Soft Foods as hard food puts a lot of pressure on the teeth surface causing discomfort to increase.
  1. 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 as this will put less pressure on the tooth and relieve the discomfort.
  1. 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.

All the above tips might relieve the discomfort caused after filling.

However, your dentist is the best person to give you suggestions based on the type of your filling material and your overall oral hygiene.

Proper Oral Hygiene To Make Your Cavity Filling Last Forever


It is recommended by the American Dental Association (ADA) to  brush your teeth twice a day for two minutes each time with a toothpaste containing fluoride. 

It is recommended to brush your teeth twice a day, once in the morning, just after waking up and once at night, just before going to bed.

You must also clean your teeth and gums, each time after you have food but not with a toothbrush. Simple rinse with water is considered good for overall oral health and hygiene.

Following this tooth brushing habit will help you prevent cavity formation in the first place and also help your cavity fillings last longer.


Yes, you can floss after a filling, but you have to be cautious of not doing it forcefully and extra cautious when the filling is on tooth edge.

Flossing after a filling must be done gently using an extra-thin floss. It is essential to curb bad bacteria and prevent interproximal caries.

It is recommended to brush twice a day for two minutes each everyday and floss twice daily even after a filling.


Therapeutic mouthwashes, as the name suggests have therapeutic action and control dental conditions like gingivitis, tooth decay and periodontal diseases. They also help remove halitosis.

Occasional use of mouthwash along with daily brushing and flossing helps keep bad oral bacteria away and thus prevents formation of cavities and allows cavity fillings to last longer.


This blog post addressed the topic, “do cavity fillings need to be replaced”. We understood what the different types of filling materials are, after how long the cavity fillings need to be replaced and why do cavity fillings need replacement. The article outlined precautions to be taken for cavity fillings to last longer including eating precautions after filling and proper oral care after filling.

FREQUENTLY ASKED QUESTIONS (FAQs): Do Cavity Fillings Need To Be Replaced

How do you know when a filling needs replacing?

A filling needs replacement when it wears out and falls off, or when the filled tooth starts experiencing pain and sensitivity, or when the filled tooth gets injured or fractured, or when the filling material gets darkened.

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

Do Cavity Fillings Last Forever?

No, unfortunately cavity fillings do not last forever. Even if you take all necessary precautions, you might end up ruining your filling because they are not durable for more than 10-15 years in case of silver fillings and 5 years in case of composite fillings.

Shelf-life of cavity fillings depend on several factors like type of filling material, oral hygiene, eating habits, habits like teeth grinding and health of surrounding teeth.

Can a filled cavity become a cavity again?

Yes! A filled cavity may reappear and become a cavity again even after filling due to bacterial contamination of the tooth cavity resulting from multiple causes such as microleakage, faulty crown placement, filling material falling out due to poor after-care, inadequate debridement and sealing of the cavity and poor oral hygiene after filling.

In order to prevent cavities from reappearing even after filling, daily brushing your teeth twice is essential along with daily flossing and occasional mouthwash.

However, if the reappearance of the cavity is due to reasons other than poor oral hygiene, then your dentist will examine and fix the issue as suitable.

If you feel any hole or pain in the tooth that has filling, immediately consult your dentist.

How do I know if I need a filling or root canal?

If you notice a hole on your tooth surface or feel a hole with your tongue but pain, sensitivity and discomfort is occasional or rare, then your cavity has not reached pulp and may need filling.

But if you notice or feel a hole with excruciating pain and sensitivity and discomfort that interferes with your daily life activities, then your cavity has reached pulp tissue and you may need a root canal treatment.

However, your dentist will examine the tooth cavity and take an x-ray. The x-ray will reveal how much the infection has spread and accordingly your dentist might suggest you a filling or a root canal.

Are White Fillings Strong?

White fillings that belong to the new generation are much stronger and can bear more pressure than the old ones.

White fillings micro-mechanically bond to the tooth structure and provide stability and strength. 

They are however less strong than amalgam fillings and last for 5 to 10 years when compared to amalgam fillings which last for more than 15 years. 

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

Do cavities only get worse?

Do cavities spread to other teeth?

Do fillings for cavities hurt?


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

Soft food diet options. Colgate

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