If you find out you’ll be needing a dental crown procedure, you may be wondering why, or how it works. A dental crown, or “cap” is one of many ways to repair damaged teeth. It is a cemented restoration that partially or completely covers the outside of the tooth. Every tooth has two parts the crown and root. The crown is the part of the tooth visible in the mouth, above the gum line on lower teeth and below the gum line on upper teeth. While replacing or repairing broken teeth may seem intimidating, it’s a relatively painless and simple procedure to receive.
Reasons for a dental crown:
- If you’re in need of a large filling that exceeds you tooth’s natural structure
- Reconstruction after a root canal
- If a tooth that is broken in a way that it might interfere with other solutions (such as overlays)
- Cracked tooth syndrome
- Broken cusps
- Excessive wear of teeth from grinding or acid erosion
If you qualify for any of these reasons, you will likely find yourself schedule a crown procedure. We’ll break down how the procedure works so you know what to expect.
Step 1: Numbing the tooth
To begin the dentist will use a local anesthetic to numb the tooth and surrounding tissue. If the procedure is associated with a root canal the dentist will likely opt for an anesthetic because the instruments will be very close to gingival tissue.
Step 2: Initial Impressions and Shade Choice
In order to create the perfect crown to fit your tooth, the dental laboratory creating your crown will need alginate impressions of both your upper and lower dental arches, made by a dental assistant. The impression is poured into a stone to make a mold to make a stone model of your tooth. The model is then sent to the lab to create the crown. You will also need to choose an accurate shade for the crown to match your other teeth if you have chosen a full ceramic or porcelain fused to metal crown (PFM).
A small impression of the teeth in the same quadrant of the tooth that requires the crown and the opposing arch is also taken before the tooth is prepared. This impression is used to create a temporary crown for you to wear until your permanent crown arrives back from the dental laboratory.
Once the impressions are complete the dentist will determine the final shade by using a shade guide.
Step 3: Preparing the tooth for the crown
A dental crown mimics the entire tooth, with a hollow space inside, like a cap or hat. The entire tooth must therefore be reduced down to accommodate the crown on top. The crown must keep bacteria from entering underneath the crown so it must fit securely.
Once the tooth in numb, the dentist may choose to place a rubber dental dam over your teeth to trap any tooth structure, old filling materials or water from falling into your mouth.
As the dentist begins reducing the tooth they must be very precise so that the crown fits properly and securely. If any decay is found during this process it will be removed and a composite core will be placed on the tooth. Composite will also be used if a root canal has been done.
The dentist will continue to shape the tooth, once the core is complete, to create a fine margin around the core of the tooth, similar to a shelf, and continue reducing the biting surface of the core until sufficient tooth and filling have been removed. This is a crucial step in the process and consequently may take the longest to get just right.
Step 4: The Final Impression
Assuring you get an accurate impression of the prepped tooth is vital to the dental crown process. Even the slightly flaw in the impression can leave you with an ill-fitting crown.
Next the dentist may choose to use a gingival retraction cord to gently push the gum tissue away from the prepared tooth. This is a thin cord, like a piece of yarn, inserted around the tooth in the gingival sulcus. Some dentist may choose to isolate the tissue in other ways, such as gingival curettage.
Once this step is complete your tooth is ready for the final impression. First the dentist will apply a polyvinyl siloxane impression material around the prepared tooth. At the same time a dental assistant will begin filling the impression tray with a corresponding impression material. Then they will insert the impression tray over your prepared tooth, and ask you to bite down. It is very important for you to remain biting into the impression until the material is fully set, which is about three to five minutes. Once set they will remove the tray and check for any bubbles or voids in the impression. If any are found it’s imperative the impression be taken again.
Step 5: Creating and Applying the Temporary Crown
A temporary crown is important for many reasons, especially protecting the prepared teeth until the permanent crown is placed. They will use a small impression from before preparing the tooth, and fill it with an acrylic resin in the chosen shade. The temporary crown is then shaped to remove rough edges and fit your tooth. Once complete, a temporary cement is apply to secure the temporary. They’ll then check your bite to assure everything lines up properly
It is very important for you to follow the post-operative instructions given to you for wearing a temporary crown. If it does come off your tooth, call your dentist immediately and book an appointment to have it re-cemented.
Step 6: Cementing the Permanent Crown
It may take a dental lab seven to ten business days to create your permanent crowns. You’ll need to schedule your appoint to cement the permanent crowns when leaving the first appointment with your temporaries in. They’ll begin the process by numbing the prepared tooth and surrounding tissue, and thoroughly cleaning the area.
Once you are completely numb they will remove the temporary crowns and the remaining cement, then completely drying the tooth. The dentist will try the crown on first and check to assure the contact between the crown and adjacent teeth is aligned. If it is too tight they may reduce the adjacent teeth, but if it is not tight enough the permanent crown may be sent back to the lab to be remade.
Once satisfied with the fit, the dentist will begin the cementing process. The prepared tooth must be completely dry, so no water or saliva may touch it. To prevent it from getting wet rolls of cotton will be inserted around the tooth. Then a desensitizing agent will be applied to help with post-op sensitivity.
The dentist will apply a bonding agent to the tooth, some may require a special light to cure it. Once the material is set, the permanent crown will be filled with cement and the dentist will apply it, removing any excess cement once complete.
Step 7: Checking Your Bite
After waiting about 10 minutes for the cement to set, the dentist will thoroughly check your bite with the new crown. Any high spots on the crown will be reduced on the opposing tooth. It is very important to have the bite correct because a high bite can lead to tooth sensitivity and tooth pain.
Step 8: Post-Operative Instructions
While your new crown should be able to endure normal wear and tear, it is not indestructible. Your dentist will provide a set of instructions you should closely follow after the procedure. You’ll need to be careful eating hard things such as candy and nuts right away. If you notice anything unusual in the days after the procedure be sure to let your dentist know right away. As always be sure to follow all basic oral hygiene practices like regular brushing, flossing and cleanings.
Getting a dental crown procedure is relatively common and safe. Plan to schedule several visits to complete the process. Now that you know the exact process you can feel confident scheduling yoru procedure.