Biaxial Flexural Strength
Pronunciation: by-AK-see-əl FLEK-shər-əl
The fracture stress of a disc-shaped dental ceramic or resin specimen loaded centrally over a support circle, generating tensile stresses equally in two perpendicular directions.
Full Definition
Biaxial flexural strength is measured using a piston-on-three-ball or ball-on-ring test configuration on thin disc specimens, producing a state of equibiaxial tensile stress at the specimen's lower surface. This geometry is considered more clinically relevant for dental ceramics than three-point or four-point beam bending because it eliminates edge-failure artefacts and better simulates the multiaxial stress states experienced by ceramic restorations under occlusal load. The result is expressed in megapascals (MPa). Editors should be aware that biaxial flexural strength values are not directly comparable to uniaxial flexural (three-point bend) strength values and should not be combined in meta-analyses without appropriate conversion or stratification. ISO 6872 specifies the biaxial flexural strength test for dental ceramics.
Usage
Usage note: Always hyphenate 'biaxial' as part of 'biaxial flexural strength'. Do not pool biaxial and uniaxial flexural strength data. Report values in MPa.
In Context
- "The biaxial flexural strength of the experimental zirconia was 1,200 MPa, exceeding the ISO 6872 Type 5 minimum." — Dental ceramics research article
- "Meta-analyses should not pool biaxial and three-point flexural strength data without statistical justification." — Systematic review methodology note