Dental implant crowns, used as a replacement for missing teeth, are supported by dental implants that act as an artificial tooth roots. There are two primary types of implant-supported dental crowns, which include:
Screw-Retained Implant Supported Crowns:
As the name suggests, these types of crowns are attached to the dental implant via a screw. A hole is made in the center of the crown to allow for the screw to pass through and attach to the implant. This hole is typically filled with a tooth-coloured composite filling material for aesthetic purposes. Screw-retained crowns can be removed if needed for repairs or maintenance, which is one of their major advantages. They also minimize the risk of cement-related complications as they do not require cement for attachment.
Cement-Retained Implant Supported Crowns:
These types of crowns are cemented onto the abutment of the dental implant. There is no hole in the crown, as there is no screw required for attachment. These crowns tend to have superior aesthetics compared to screw-retained crowns, especially in the anterior region where the screw hole might be noticeable. However, one downside is the risk of cement-related complications if the excess cement is not completely cleaned off during the procedure. Another disadvantage is that they are not easily removable without potential damage to the crown or implant.
In addition, there are some variations of the two primary types, such as:
Custom Abutment Implant Supported Crowns:
These are a type of cement-retained crown where the abutment (the part that connects the implant and the crown) is custom-made for the patient. This allows for more natural contours and an emergence profile, which can lead to a more aesthetic result.
Hybrid or Conversion Implant Supported Crowns:
These crowns start out as screw-retained but are converted to a cement-retained crown after the screw is torqued to the implant. The screw access hole is then sealed with composite resin, and the crown is cemented to a pre-made abutment.
The choice of crown type depends on several factors, including the location of the implant, the patient's oral hygiene, aesthetic considerations, and the clinician's preference. However, all types can provide durable, long-lasting, and aesthetically pleasing results when done correctly.
There are both benefits and drawbacks to each option.
Screw-Retained Dental Implant Supported Crowns:
Advantages:
Reversibility: Screw-retained crowns can be easily removed and reinserted without damaging the crown or the implant. This feature is beneficial if adjustments or repairs are needed.
No Residual Cement: With screw-retained crowns, there's no risk of residual cement getting trapped under the gum line, which could lead to inflammation or infection.
Immediate Loading: In many cases, screw-retained crowns can be loaded immediately, enabling quicker restoration of function and aesthetics.
Disadvantages:
Aesthetic Limitations: The presence of the screw access hole, which is often filled with tooth-coloured filling material, can limit the aesthetic outcome, especially for anterior teeth.
Potential for Loosening: The screw may become loose over time, requiring further visits for tightening or replacement.
Complex Occlusal Adjustment: Achieving optimal occlusion can be more challenging with screw-retained crowns as adjustments have to be made off-site.
Cement-Retained Dental Implant Supported Crowns:
Advantages:
Aesthetic Excellence: Since there's no screw access hole, cement-retained crowns often provide superior aesthetic results, especially for front teeth.
Ease of Fabrication: The process of creating cement-retained crowns is less technically sensitive and requires less chair time.
Simple Occlusal Adjustment: Adjustments to achieve proper bite can be made chairside, making it easier and quicker to perfect occlusion.
Disadvantages:
Risk of Residual Cement: Improperly cleaned residual cement can cause inflammation, infection, or bone loss around the implant.
Irreversibility: Cement-retained crowns are permanently affixed, making retrievability and modifications difficult without damaging the crown or the implant.
Unpredictable Retention: The cementing process might have inconsistencies, leading to unpredictable retention strength of the crown.
At Toronto Smile Design - Yokville Dental, we use state-of-the-art Primescan technology to take digital impressions of patients' mouths. This allows us to create precise and customized implant crowns, regardless of the chosen type. Each type of crown has its strengths and weaknesses, and the choice often depends on the specific clinical situation, the patient's preference, and aesthetic considerations. Dr.Johnson carefully considers these factors to provide the best dental solution for every individual patient.
