Relative Dentine Abrasivity
Also written as: RDA — Relative Dentine Abrasivity
A standardised numerical index measuring the abrasive potential of a dentifrice or prophylaxis paste on dentine, used to guide safe product selection.
Full Definition
Relative Dentine Abrasivity (RDA) is an ISO-standardised measure (ISO 11609) that quantifies how abrasive a toothpaste or prophylaxis paste is relative to a standard reference material. RDA values below 70 are considered low abrasivity, 70–100 medium, and values approaching 250 are at the maximum permitted threshold for commercial toothpastes. Dental hygienists reference RDA when advising patients on dentifrice selection, particularly those with exposed dentine, and when selecting prophylaxis pastes for polishing procedures. Editors must spell out 'Relative Dentine Abrasivity' on first use, preferring the British English 'dentine' over 'dentin' unless the publication follows American conventions. The abbreviation 'RDA' may clash with 'Recommended Dietary Allowance' in dual-specialty texts.
Usage
Usage note: Always expand RDA on first use to prevent confusion with 'Recommended Dietary Allowance'. Note British vs. American spelling: 'dentine' (British) vs. 'dentin' (American).
In Context
- "Patients with exposed root surfaces should be advised to use a dentifrice with a Relative Dentine Abrasivity (RDA) of 70 or below." — Patient education leaflet
- "The article used 'RDA' without expansion; in a nutrition-and-dentistry context, clarify that RDA denotes Relative Dentine Abrasivity, not Recommended Dietary Allowance." — Cross-specialty manuscript editing