In situations when a tooth does not have sufficient remaining tooth structure to support the planned restoration, the anatomical crown may need to be "built up" using a restorative material foundation. A 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. 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.
The Delta Dental National policy states a core buildup is generally indicated if all of the following conditions are met:
- A significant portion of tooth structure (50% or more) is fractured or carious
- The preparation is at or below the gingival crest
- Less than 3mm of sound dentin remains vertically above the preparation line in opposing walls where the crown margins will be located
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.
Sources: Christensen, Gordon. Clinicians Report, August 2018, Volume 11, Issue 8