There are situations when a tooth does not have sufficient remaining tooth structure to support the planned restoration. In these cases, the anatomical crown may be “built up” using a restorative material foundation. These procedures are performed on teeth that have an overall favorable long-term prognosis. Core Buildup is indicated for teeth with significant loss of coronal tooth structure due to caries or trauma in which insufficient tooth structure remains to adequately retain an indirect restoration.
Gordon Christensen DDS, MSD, PhD, ScD, regarded as one of the most renowned authorities on dental materials and clinical practice, has addressed these questions in several articles published over the years in the Journal of the American Dental Association. Dr. Christensen suggests that the tooth involved be prepped as ideally as possible. All remaining restorative material should then be removed if any doubt exists about retention and underlying pathology. An assessment should then be made of the remaining tooth structure. If more than 50% of the prepped coronal tooth is missing and there is not at least a two to three millimeter collar of sound tooth structure remaining at the gingival margin, a core buildup should be added.
Current DDKS policy states a core buildup is generally indicated if all of the following conditions are met:
- A significant portion of tooth structure (50 percent or more) is fractured or carious;
- The preparation is at or below the gingival crest; and
- Less than 3 mm of sound dentin remains vertically above the preparation line in opposing walls where the crown margins will be located.
Code D2950 is frequently confused with code D2949 (restorative foundation for an indirect restoration – Placement of restorative material to yield a more ideal form, including elimination of undercuts). D2949 is the appropriate code when sufficient axial wall height and width exists but a restorative material is needed to fill in undercuts, box forms, or concavities created by previously placed deep occlusal restorations.
DDKS requires a pre-op x-ray to be submitted with the claim to ensure the above criteria is met. Although not required, it is also suggested that an intraoral photo taken post prep be submitted in addition to the pre-op x-ray to help show the need for the core build-up if the pre-op x-ray doesn’t demonstrate the above required criteria for a build-up.