Implant Stability Quotient
A numerical score (1–100) derived from resonance frequency analysis that quantifies the mechanical stability of a dental implant at a given time point.
Full Definition
The Implant Stability Quotient (ISQ) is a dimensionless value generated by resonance frequency analysis (RFA) devices such as Osstell. It reflects the stiffness of the implant-bone interface, with higher values indicating greater primary or secondary stability. Editors should note that 'Implant Stability Quotient' is the full form behind the abbreviation ISQ; using the full form and the abbreviation interchangeably in the same document is acceptable on first mention with parenthetical introduction. Scores below 60 generally indicate marginal stability, while scores above 70 are considered clinically favorable. The term is proprietary in origin but has entered general clinical usage.
Usage
Usage note: Do not conflate with insertion torque; ISQ measures resonance-based stability, whereas insertion torque measures resistance during placement. Capitalise each word on first use when writing the full form.
In Context
- "The clinician recorded an implant stability quotient of 74 at the time of placement, supporting a decision to proceed with early loading." — Surgical case report
- "Serial implant stability quotient measurements were taken at weeks 0, 4, and 8 to track osseointegration progress." — Clinical research article