Masking (Blinding)
A methodological procedure in clinical trials in which participants, investigators, or outcome assessors are kept unaware of treatment allocation to reduce performance and detection bias.
Full Definition
Masking—preferred over 'blinding' in contemporary trial reporting to avoid ableist connotations—is a core strategy to minimise bias in dental clinical trials by preventing one or more parties from knowing which intervention a participant has received. In dental research, complete masking of all parties (triple masking) is often logistically challenging; for example, it may be impossible for a clinician delivering scaling to be masked to treatment allocation. Editors reviewing clinical trial manuscripts should verify which parties were masked (participant, clinician, outcome assessor, data analyst) and whether a credible masking procedure is described. CONSORT guidelines require explicit reporting of masking status. The terms 'blinding' and 'masking' are used interchangeably in older literature; many journals now prefer 'masking' as the preferred editorial standard.
Usage
Usage note: 'Blinding' and 'masking' are synonymous in trial reporting; check the target journal's style preference. 'Allocation concealment' is distinct—it refers to preventing foreknowledge of upcoming assignments, not concealing current allocations.
In Context
- "Outcome assessors were masked to group allocation throughout the study, and masking integrity was assessed at the final visit." — Methods section of a dental RCT
- "Complete masking of the treating clinician was not feasible due to the nature of the surgical intervention." — Limitations section of a periodontal surgery trial