crown-to-implant ratio
The proportional relationship between the length of the prosthetic crown and the length of the implant fixture embedded in bone, used to assess biomechanical risk.
Full Definition
The crown-to-implant ratio (C:I ratio) describes the proportion of the clinical crown height above the bone crest relative to the osseointegrated length of the implant fixture. A high crown-to-implant ratio can generate excessive lateral forces on the implant, increasing the risk of prosthetic failure or bone loss. This ratio is an important planning and documentation parameter in implant case files and laboratory design notes. Editors must note the standardised use of a colon in the ratio expression (C:I) and the hyphenation of the full term. The concept is analogous to the crown-to-root ratio used in conventional prosthetics but is not identical.
Usage
Usage note: Always hyphenate the full term. When abbreviated, write C:I ratio with a colon. Do not confuse with crown-to-root ratio, which applies to natural teeth only.
In Context
- "The implant case design notes flagged a crown-to-implant ratio of 2:1 as a biomechanical concern requiring clinician review." — Implant laboratory case documentation
- "A favourable crown-to-implant ratio is generally considered to be equal to or less than 1:1." — Implant prosthetics clinical guideline