Vickers Hardness
Pronunciation: VIK-erz HAR-d-ness
Also written as: VHN — Vickers Hardness Number
A measure of a dental material's resistance to permanent surface indentation, expressed in Vickers Hardness Number (VHN) and determined using a pyramidal diamond indenter.
Full Definition
Vickers hardness testing applies a standardised diamond pyramid indenter under a specified load to a polished material surface, and the diagonal length of the resulting indentation is measured to calculate the VHN. In dental materials research, VHN is routinely used to compare the hardness of enamel, dentine, restorative materials, and ceramic substrates, offering insight into wear resistance and susceptibility to surface degradation. Higher VHN values indicate greater hardness; for reference, enamel has a VHN of approximately 340 and dentine approximately 68. Editors should ensure authors specify the applied load and dwell time when reporting VHN, as these affect the result.
Usage
Usage note: Capitalise 'Vickers' as a proper noun. Report as 'VHN' with the numerical value (e.g., 340 VHN). Do not conflate with Knoop hardness, which uses a different indenter geometry.
In Context
- "The mean Vickers hardness of the CAD/CAM composite blocks was 132 VHN, compared with 98 VHN for the hand-mixed counterpart." — Materials science research article
- "Surface hardness was assessed by Vickers hardness testing under a 500 g load for 15 seconds." — Laboratory methods section