Abutment Definition
An abutment is a small object that is used to connect the crown or other dental restoration to the implant fixture. The implant fixture is a post, often made of titanium, that is inserted into a hole drilled into the patients jawbone. Once in position, it takes several months for osseointegration to occur. Once this process is complete, the post will have sufficient stability to act as the root of the tooth, to which the abutment is used to connect the crown or other dental restoration. Most fixed partial dentures and crowns are either adhered using dental cement or with a lag screw.
The abutment is typically made out of materials like gold, stainless steel, or titanium. A ceramic abutment may be used for patients who desire a more natural look; however, the drawback to this approach is that the compressive strength is not as strong as traditional metal materials, which is why this option may be discouraged, especially for implants being placed in posterior molar areas, where chewing forces will be greater.
Prefabricated Abutments
Prefabricated abutments range in shape, size and type. There are several factors that will determine what type of abutment is best suited for you, including whether you are getting a removable denture, fixed bridge, or crown, whether the abutment is going to be attached with special retainers, lag screws, or dental cement, and where in the mouth the implant is being placed.
Custom Made Abutments
Designing a custom-made abutment requires first making an impression of the top of the implant to naturally fit with the surrounding gingiva and teeth. The material, shape, and size will vary depending on what type of implant is needed and may include special anchoring systems for patients who are having removable dentures placed. A custom-made abutment may also be designed with the crown and abutment as one piece, after which a special screw can be used to secure the implant. Following attachment of the implant, another impression is made and sent to the laboratory to design a restoration that looks and feels natural and is customized to your unique mouth. Once this prosthesis is finished, it will be placed and tested to ensure the bite is correct and that the tooth feels natural and comfortable, after which the crown is screwed or cemented to the abutment and the dental implant process will be complete.
One, Two, and Three-Piece Implants
- One-piece implants (OPI) utilizes the trans-mucosal abutment and often involves the crown being placed shortly after the implant is placed.
- Two-piece implants are cold welded to the implant, which decreases the chance of colonization and microbial leakage between the abutment and implant, which can result in implant failure. As a result, this type of implant has improved abutment stability, torque maintenance, micro-organ formation, and seal performance.
- Three-piece implants involved fixing the abutment on the implant by using a dental torque wrench to tighten the screw butt joint to ensure the crown does not loosen and complications do not develop.