Crownlays or Retention Form?
The Biomimetic “Crownlay” has been the subject of popular discourse regarding conservative dentistry versus traditional mechanically-retained crowns. Biomimetic dentists say you can retain anything with proper adhesive procedures, while others argue that traditional retention form techniques are key to long term results. While the major idea of crownlays is to be conservative, another concept also reinforces the use of crownlays: the “Compression Dome Concept”.
What is the “Compression Dome Concept”?“
Evidence now supports the concept that the enamel on a tooth acts like a compression dome, much like the dome of a cathedral.” (1)
Essentially, enamel acts as a compression dome which protects the dentin from tensile forces which damage the tooth and lead to cracks propagating, biting pain and further deterioration of the tooth structure.
Traditional crown preparations remove the majority of this compression dome in favor of mechanical retention forms leaving the natural underlying tooth structure less reinforced than it already was.
Overlay preparations allow you to maintain the “bio-rim” which is the area below the height of contour of posterior teeth which is usually removed with traditional crown preparations. In the compression dome concept, “the bio-rim is the walls supporting the dome” (2).
General Dentist. Author at The Tooth Bank and create content for our social media with a focus on providing information for new dentists..