Understanding Dental Crowns: What Are They Made Of?

Dental crowns, often called “caps,” are custom-made coverings that fit over a damaged or decayed tooth. Their primary purpose is to restore the tooth’s shape, size, strength, and appearance. They are designed to be durable and protect the underlying tooth structure from further damage.

The materials used to make crowns vary, and this is a crucial factor when considering if a dentist can drill through one. Common crown materials include:

• Porcelain/Ceramic: These are aesthetically pleasing and closely mimic natural teeth. They can be strong but may be more brittle than other materials.
• Metal Alloys: Gold, palladium, nickel, or chromium alloys are very strong and durable. They are less likely to chip or break but are not tooth-colored.
• Porcelain-Fused-to-Metal (PFM): These combine the strength of metal with the natural look of porcelain. They are a popular choice, offering a good balance of aesthetics and durability.
• Zirconia: A very strong and durable type of ceramic, often used for its strength and ability to be milled into precise shapes.

The hardness and composition of these materials dictate how easily a dental drill can penetrate them. For instance, drilling through a gold crown is generally much easier than drilling through a solid zirconia crown.

When Might a Dentist Need to Drill Through a Crown?

While dentists prefer to avoid drilling through a crown if possible, there are specific scenarios where it becomes necessary. These situations typically involve addressing problems that have developed beneath or around the crown, or when the crown itself needs modification.

Common Reasons for Drilling Through a Crown:

• Accessing Decay: If decay develops under the crown (recurrent decay), the dentist needs to remove the decay to prevent further damage to the tooth. Drilling through the crown is often the only way to reach it.
• Removing a Crown: Sometimes, a crown may need to be removed to perform root canal treatment, repair a fractured tooth, or replace a failing crown. While complete removal is often the goal, sometimes initial drilling is part of the process to loosen or section the crown.
• Adjusting Fit or Bite: Occasionally, a new crown might feel slightly high or interfere with the patient’s bite. Minor adjustments might be made by drilling and polishing the crown’s surface.
• Retrieving a Lost Filling or Post: If a filling or post that was placed before the crown was cemented becomes loose or needs to be removed, drilling through the crown might be required to access it.
• Diagnosing Issues: In rare cases, a dentist might drill a small hole to take a closer look at what’s happening beneath the crown, especially if there are signs of infection or cracks.

It’s important to remember that dentists are trained to use the least invasive methods possible. If drilling through a crown is the recommended course of action, it’s because other options are either not feasible or less effective for the specific problem.

The Process: How Do Dentists Drill Through Crowns?

Drilling through a dental crown isn’t like drilling into a natural tooth. The materials are different, and the approach needs to be precise. Dentists use specialized equipment and techniques to ensure the procedure is as safe and efficient as possible.

Tools of the Trade:

• High-Speed Dental Drills: These are powerful tools that spin at very high speeds, allowing for efficient cutting through various materials.
• Specialized Burs: Dental burs are the cutting tips of the drill. Dentists have a variety of burs made from different materials (like diamond or carbide) and with different shapes and grits, suitable for cutting through porcelain, metal, or composite materials.
• Water Spray/Coolant: Water is continuously used during drilling to cool the bur and the tooth, preventing overheating and reducing the risk of damage to the underlying tooth structure or pulp.
• Suction: High-volume suction is used to remove water, debris, and tooth fragments from the mouth.

The Step-by-Step Approach:

1. Anesthesia: Before any drilling, the dentist will typically administer local anesthetic to numb the area, ensuring your comfort throughout the procedure.
2. Isolation: The tooth might be isolated using a dental dam or cotton rolls to keep the area dry and clear of saliva, which improves visibility and prevents debris from entering the airway.
3. Careful Drilling: The dentist will carefully select the appropriate drill bit and speed. They will start drilling, often at a specific point on the crown (e.g., the chewing surface), to gain access.
4. Access and Assessment: Once access is achieved, the dentist will assess the underlying issue, whether it’s decay, a damaged tooth structure, or the need for further treatment.
5. Treatment: The necessary treatment is then performed, which could involve removing decay, cleaning canals, or preparing the tooth for a new restoration.
6. Restoration or Replacement: Depending on the extent of the work, the crown might be repaired (if possible) or, more commonly, a new crown will be fabricated and cemented after the underlying issue is resolved.

The goal is always to be as minimally invasive as possible, preserving as much healthy tooth structure as can be salvaged.

Can a Dentist Drill Through ANY Crown?

While dentists can drill through most types of dental crowns, the difficulty and potential for damage vary significantly depending on the crown’s material. This is where the “shocking truth” might lie – not all crowns are created equal when it comes to drilling.

Material Matters:

• Metal Crowns (Gold, Base Metal Alloys): These are generally the easiest to drill through. Their metallic nature makes them relatively soft compared to ceramics, allowing dentists to penetrate them with standard dental burs.
• Porcelain-Fused-to-Metal (PFM) Crowns: These are moderately difficult. The porcelain layer is harder than metal, but the underlying metal can be drilled. Dentists often have to navigate both materials.
• All-Ceramic/All-Porcelain Crowns: These are typically harder and more brittle than PFM crowns. Drilling through them can be challenging and carries a higher risk of chipping or fracturing the crown, especially if done improperly.
• Zirconia Crowns: Zirconia is exceptionally strong and hard, making it one of the most difficult materials to drill through. Dentists often use specialized diamond burs and careful techniques to penetrate zirconia. In many cases, if access is needed through a zirconia crown, it might be more practical to section and remove the entire crown rather than attempt precise drilling.

It’s rare for a dentist to drill through a perfectly intact crown solely for aesthetic reasons. The primary driver is always a clinical need related to the health of the underlying tooth.

Table: Crown Material vs. Drillability

This table highlights why a dentist’s choice of tools and approach is so critical. A dentist performing this procedure needs to have a deep understanding of restorative materials.

Alternatives to Drilling Through a Crown

Because drilling through a crown can be challenging and carries risks, dentists will always explore alternative solutions first. The goal is to preserve the restoration whenever possible, or to remove it cleanly if necessary.

Common Alternatives:

• Crown Removal Kits: For crowns that need to be removed entirely, dentists may use specialized instruments designed to carefully loosen and remove the crown without damaging it, especially if the crown is intended to be reused.
• Sectioning the Crown: Instead of drilling a hole, the dentist might use a high-speed drill with a fine disc to cut the crown into sections, allowing for easier removal. This is often done for PFM or metal crowns.
• Non-Invasive Diagnostic Tools: For initial assessment, dentists might use X-rays, intraoral cameras, or transillumination (shining a light through the crown) to detect issues without drilling.
• Waiting and Monitoring: If a small issue is detected and isn’t causing immediate pain or significant damage, a dentist might opt to monitor it over time.

The decision to drill or use an alternative method is always based on the specific clinical situation, the type of crown, and the dentist’s professional judgment.

What Happens After Drilling Through a Crown?

The aftermath of drilling through a crown depends entirely on why it was done. If the goal was to access decay, the decay will be removed, and the tooth structure underneath will be assessed. If the tooth structure is sound, the dentist might be able to repair the small hole in the crown with a composite filling material. However, this is often a temporary fix, and the crown may eventually need replacement.

More commonly, if drilling was done to gain access for a root canal or to address significant damage, the original crown will likely need to be removed and a new one fabricated. The process after drilling usually involves:

• Cleaning and Treating: Addressing the underlying dental issue (e.g., removing decay, performing a root canal).
• Restoring Tooth Structure: If significant tooth structure was lost, a buildup or post and core might be needed to support a new crown.
• Impression Taking: A mold of the prepared tooth is taken to create a new crown.
• Temporary Crown: A temporary crown is often placed while the permanent one is being made.
• Final Cementation: The new permanent crown is cemented onto the tooth.

It’s essential to follow your dentist’s post-procedure instructions carefully to ensure the best outcome for your oral health.

Can You Feel the Drill Through a Crown?

This is a very common concern! The good news is that if the procedure is done correctly, you shouldn’t feel pain. Dentists use local anesthetic to completely numb the tooth and the surrounding gum tissue before any drilling begins. You might feel vibrations or pressure, which is normal, but pain should not be present.

If you do experience any discomfort during the procedure, it’s crucial to signal your dentist immediately. They can administer more anesthetic if needed or adjust their technique.

The Cost Factor: Is Drilling Cheaper Than Replacement?

Generally, drilling through a crown to perform a minor repair (like sealing a small access hole after a root canal) is less expensive than replacing the entire crown. However, this is not always the case.

If the drilling is part of a larger procedure, like a root canal, the cost of the root canal treatment itself will be significant. Furthermore, if the drilling compromises the integrity of the crown, or if the underlying tooth requires extensive work (like a new post and core), then a crown replacement will likely be necessary anyway. In such scenarios, the cost of drilling might be factored into the overall cost of replacement, and attempting to save the old crown might not be cost-effective in the long run.

It’s always best to discuss the estimated costs and the reasons behind them with your dental provider.

Maintaining Your Dental Crowns

Preventing the need for dentists to drill through your crowns starts with proper care and maintenance. By taking good care of your teeth and gums, you can extend the life of your dental restorations.

Tips for Crown Care:

• Good Oral Hygiene: Brush your teeth twice a day with fluoride toothpaste and floss daily. Pay special attention to the gum line around the crown to prevent plaque buildup and gum disease.
• Avoid Sticky Foods: Foods like caramel, toffees, and hard candies can potentially pull on or damage crowns, especially if the cement is weakened.
• Use a Mouthguard: If you grind your teeth (bruxism) or play contact sports, wear a custom-fitted mouthguard to protect your crowns and natural teeth from excessive force. You can learn more about mouthguards from the American Dental Association (ADA) here.
• Regular Dental Check-ups: Visit your dentist regularly (usually every six months) for professional cleanings and examinations. They can detect early signs of decay or problems with the crown before they become serious.
• Be Gentle: Avoid using your teeth as tools, such as opening packages or biting hard objects.

Adhering to these practices significantly reduces the risk of issues that might necessitate drilling through your crown.

Frequently Asked Questions (FAQ)

Can a dentist drill through a porcelain crown?

Yes, a dentist can drill through a porcelain crown, but it requires specialized burs, often diamond-tipped, due to porcelain’s hardness. It carries a higher risk of chipping or fracturing the crown compared to drilling through metal crowns. Dentists will assess the situation carefully and may opt for complete crown removal if necessary.

What if a dentist drills into my nerve through a crown?

If a dentist accidentally drills into the nerve of your tooth through a crown, you would likely feel significant pain, even with local anesthetic. In such a rare event, the dentist would stop immediately, assess the damage, and likely recommend a root canal treatment to remove the pulp and save the tooth. This is why dentists use precise techniques and coolant during drilling.

Will drilling damage my natural tooth under the crown?

The goal of a dentist is always to avoid damaging the natural tooth structure underneath. They use specialized burs and techniques, along with water coolant, to carefully drill through the crown material. If decay is the reason for drilling, the focus will be on removing the decay while preserving as much healthy tooth as possible. If the underlying tooth is already compromised, the dentist will work to stabilize it.

How do dentists remove a crown if they don’t drill through it?

Dentists have several methods for removing crowns without necessarily drilling through them. They might use specialized instruments to gently loosen the crown by applying pressure or vibration. Sometimes, they use a dental drill to cut a precise slot or section through the crown, which then allows it to be pried off more easily. The choice of method depends on the type of crown, the cement used, and the dentist’s assessment.

Is it normal for a crown to feel rough after drilling?

If a dentist drills through a crown for minor adjustments, it might feel slightly rough initially. However, they will typically polish the area smooth to prevent irritation to your tongue or cheek. If the roughness persists or causes discomfort, you should contact your dentist for a follow-up adjustment.

Can a dentist repair a crown after drilling a hole in it?

In some cases, yes. If a small access hole was made, particularly for a root canal treatment, a dentist might be able to repair the hole with a tooth-colored composite filling material. However, this repair might not be as durable as the original crown