Innerpage Hero image
Advanced general and cosmetic dentistry
delivered with complete comfort.
Request an Appointment

Why Do I Have a Cavity Beneath My First Molar Crown?

Posted by AllSmiles

Two dental crowns, for information on cavity beneath dental crowns
Dental crowns

I received three dental crowns in 2019. After my yearly exam, x-rays, and cleaning last week, my dentist said that the top left first molar crown has a cavity beneath it. I regret not getting a second opinion because last year, I mentioned to my dentist that I had a toothache on and off in the tooth, but she didn’t pursue it. Why do I have a cavity beneath a crown? I had a challenging appointment due to anxiety when I got the crowns, and I don’t want to think about getting a new one. Thanks. Elyssa from Arlington, VA


It is unusual to find decay beneath a relatively new crown. Dr. Michalski would need to examine your crown and x-rays, but we will explain how decay can develop.

Why Do You Have a Cavity Beneath a Dental Crown?

Two reasons you may have a cavity beneath a dental crown include your dental history and the crown placement.

  • Your dental history – People with a history of cavities may develop decay beneath a dental crown.
  • The crown placement – If the margin where your crown and tooth meet is not smooth or has gaps, bacteria, plaque, and decay can thrive. If your dentist does not detect decay during your yearly exams and x-rays, the decay will progress, and you will begin to feel sensitivity and pain.

How Long Do Dental Crowns Last?

A well-made and precisely placed dental crown can last five to ten years. Insurance companies will not provide benefits for a replacement crown fewer than five years old. Most cosmetic dentists would be embarrassed to find decay beneath a crown they placed.

We recommend finding an advanced cosmetic dentist to examine your tooth, crown, and x-rays.

Will You Need a New Dental Crown?

If you have a cavity beneath a dental crown, a dentist must remove the crown and cavity. You may need a new crown. When you get a second opinion, ask the dentist about sedation options to help you relax during your procedure.

Dr. Thaddeus Michalski, a Rocky Hill, Connecticut dentist and Diplomate of the International Congress of Oral Implantologist, sponsors this post.