A dental buildup, also known as a core buildup, is a reconstructive procedure used to restore a tooth that has lost a significant amount of its natural structure. The purpose of this technique is to create a new, stable base that can adequately support a final restoration, such as a dental crown. When extensive damage has occurred, the buildup replaces the missing portion, allowing a severely compromised tooth to be salvaged and prepared for long-term protection.
Defining the Core Restoration
A dental core buildup becomes necessary when insufficient sound tooth structure remains to ensure the long-term success of a crown. This deficit often results from extensive dental decay requiring the removal of large amounts of natural tooth material. Severe fractures, trauma, or the replacement of very large, failed fillings can also compromise the tooth’s ability to support a crown directly. Teeth that have undergone root canal therapy frequently require a core buildup because the procedure, combined with the original damage, leaves the tooth hollowed out and weakened.
The goal of the buildup is to reconstruct the missing dentin and enamel, forming a solid, anatomical foundation beneath where the crown will eventually sit. This new core must be structurally sound and properly shaped to accept the crown preparation. Common materials include composite resin, which is tooth-colored and bonds adhesively to the remaining structure. Other options include glass ionomer or, in some cases, amalgam, though adhesive composite materials are generally favored for conserving natural tooth structure.
When the tooth has lost substantial coronal structure, especially after a root canal, the dentist may incorporate a fiber or metal post into the root canal space. This post acts as an anchor deep within the root, providing additional support for the core material when little tooth structure remains above the gum line. The selection of the material and whether a post is necessary depends on the degree of damage to the individual tooth.
The Step-by-Step Procedure
The process of placing a dental buildup begins with the preparation of the remaining tooth structure. The dentist first administers a local anesthetic to ensure patient comfort. All compromised material, including decay, old fillings, and unsupported segments, is meticulously removed to leave only healthy, clean tissue.
Moisture control is an important step, as most modern composite core materials require a dry field for successful bonding. The tooth is often isolated using a rubber dam or cotton rolls to prevent contamination from saliva. If the tooth requires shaping, a thin metal or plastic matrix band may be placed around the tooth to act as a temporary wall.
A chemical bonding agent is then applied to the internal surfaces of the remaining tooth structure. This usually involves etching the surface with a mild acid to create microscopic pores, followed by the application of a primer and adhesive. This adhesive layer is often cured with a specialized light to prepare the tooth for the core material.
The core buildup material, typically a dual-cure or self-cure composite resin, is then placed into the prepared tooth structure. The material is injected or packed into the missing areas, often slightly overfilling the space to ensure complete coverage. Once the material has set, the matrix band is removed. The newly formed material is then precisely shaped and contoured with rotary instruments to resemble the prepared form of a natural tooth, creating the foundation for the custom-made crown.
The Build Up’s Role in Crown Retention
The dental buildup is a structural intermediary; it is not meant to serve as the final chewing surface but as a stable foundation for the permanent crown. Its primary function is to provide the necessary bulk and height for the crown to fit over and seat properly. A crown requires a specific geometry, including sufficient height and taper, to resist dislodgement from the forces of chewing. The buildup fulfills this need by ensuring the tooth preparation has adequate surface area and form for mechanical retention.
Without this reconstructed core, a crown placed directly onto a severely damaged tooth might lack the friction fit and structural support required to withstand normal oral forces. This increased surface area allows the dental cement to create a secure, long-lasting bond between the crown and the tooth. By reinforcing the remaining tooth structure and providing the correct shape, the core buildup helps ensure the final crown remains securely in place for years, restoring the tooth’s function and integrity.