Is this gap between my crown and gum normal?

Have you ever wondered how a well-fitting crown should sit above your natural tooth?

While a dental crown is meant to restore your tooth and ensure its longevity, any gap or defect can become an open invitation for bacteria, posing a threat to your oral health.

So, what should you do when faced with a gap between your crown and gum? Before jumping to conclusions, it's crucial to differentiate between "bad gap" requiring prompt attention and "normal crown placement."

In this blog post, we will explore the factors that contribute to a gap between your crown and gum, understand when it's a cause for concern, and discover the available treatment options.

What does a "bad" gap between crown and gum look like?

A bad gap is when there's an open space between the dental crown and the underlying tooth, creating a space where bacteria and food particles can easily get in.

The crown must be firmly attached to the tooth, leaving no gaps. Any defects or leakage under the crown can make the tooth more vulnerable to issues like cavities and infections.

When there's this kind of gap, it's often noticeable with darkening along the gum line, decay, and a crown that feels looser and less stable.

A gap between the crown and gum can actually mean the crown's normal placement

It's important to distinguish between the "Bad Gap" between the crown and the underlying tooth and the gap that represents the normal crown placement.

When the crown is put in place, the area where the crown meets the tooth is called the margin.

The crown margin can have different positions. For instance, when it sits above the gum line, it's called supragingival.

In this case, it's normal to notice a small gap between the crown and the gum. As long as there's no leak under the crown, there's nothing to worry about.

Your dentist has intentionally chosen this placement for biological reasons. That's because the supragingival margin is the healthiest for your gums and makes oral hygiene and cleaning easier.

The downside? It's less aesthetic than other options (since the transition between the crown and the underlying tooth is clearly visible).

There are also other types of crown margins your dentist can choose from:

• Subgingival: The crown margin is concealed and placed below the gum line. This is the most aesthetically pleasing position but the most harmful to gum tissue.


• Equigingival: The crown margin is positioned at the same level as the gum line. It is less aggressive than the previous one but also requires regular care.

How Should a Well-Fitting Crown Look Like?

A good-fitting crown can protect your tooth and increase its lifespan. On the other hand, an ill-fitting crown can actually do the opposite and cause problems like cavities, gum disease, and infections. So, what should a good-fitting crown look like?

First and foremost, a well-made crown should fully cover your tooth, leaving no gaps where bacteria and saliva can seep through. It must be firmly attached to the tooth and remain stable when chewing or brushing. This ensures that no harmful substances can penetrate the crown and cause damage.

Secondly, the height and width of the crown are crucial. It should be adjusted properly to fit in with your neighboring teeth, keeping light contacts and having the same height as them. If a crown sits too high or puts excessive pressure on the nearby teeth, it can create tension and lead to issues like wear, sensitivity, and bite problems.

Lastly, the crown must not harm your gums. There should be no gap between the tooth and the crown, as plaque can build up and cause irritations. Additionally, the crown should not dig too deeply into the gum line, as this can damage the gum tissue and make oral hygiene difficult.

Warning signs

Some of the indicators that may indicate an unhealthy gap between crown and gum include:

1. Flossing Difficulty: If flossing in the affected area causes the floss to catch or tear, it suggests an issue with the crown's fit.


2. Surface Roughness: Running a toothpick lightly along the junction between the crown and tooth and feeling rough or uneven surfaces may indicate the presence of a gap beneath the crown.


3. Discoloration and Odor: Black discoloration along the crown's edge, soft white material coming from the gap, as well as bad taste and bad breath, can be associated with these defects and potential cavities.

Complications of an open gap between the crown and gum

If left unchecked, a leak under the crown can lead to a number of complications:

• Increased Plaque Buildup: Gaps can harbor more bacterial plaque. And more bacteria means a higher threat to your oral health.


• Cavities: Bacteria and debris can accumulate in the gap, leading to tooth decay.


• Receding Gums: Gaps can contribute to gum recession, leaving the tooth root exposed.


• Gum Disease: Inadequate cleaning of the gap can cause gum inflammation and periodontal disease.


• Crown Loosening: Gaps may result in a loose crown that requires immediate attention.


• Bone Loss: Untreated gaps can lead to bone deterioration around the affected tooth.


• Tooth Infection: Bacteria entering the gap can cause an infection in the underlying tooth.

What may cause a gap between the crown and gum?

There are several potential reasons why a gap may appear between your crown and gum.

• Improper Crown Preparation: Technical errors during the crown preparation process can result in a poorly fitting crown. If the crown is not placed correctly, it can develop leakage around its borders, leading to unsightly gaps.


• Aging or Worn-out Crown: Over time, even well-made crowns can show signs of wear and aging. The cement that holds the crown to the tooth may deteriorate, causing the restoration to become loose and come out.


• Cavity Formation: Recurrent or secondary cavities can occur under a crown due to factors such as poor oral hygiene, a poorly fitting crown, or incomplete removal of initial decay. The decay will gradually eat away at the underlying tooth and cement, leading to more serious complications.


• Gingival Recession: This leads the gum to pull away from the crown. As a result, the distance between the crown margin and the gum line will increase, and the tooth will appear longer than it used to be. The tricky part is that gingival recession can progress over time, leading to additional issues like root decay, tooth sensitivity, and cosmetic concerns.

Treatment Options to Fix the Gap Between Your Crown and Gum

When a gap exists between your crown and gums, there are several treatment options available to address the issue:

1. Replacement of the Crown: In most cases, your dentist will recommend replacing the old crown with a new, properly fitting one. This ensures a better seal and prevents further complications.


2. Addressing Underlying Problems: Before placing a new crown, any existing problems need to be taken care of. If there's a cavity, it will be removed and filled with dental material. If there's a tooth infection, a root canal treatment may be needed before the new crown is placed.


3. Treating Receding Gums: If the crown is securely in place, and the "gap" you are dealing with refers to receding gums, a different approach may be considered. Treatment may involve deep dental cleaning, known as scaling and root planing, to remove plaque and infected tissue. In some cases, your dentist may recommend a gum graft procedure to cover the exposed root and restore your tooth's appearance.