Load deformation behaviour during a diametral test.

The deformation of a cylinder in the diametral mode proved to be a linear function of the applied load for silicate cements, glass ionomer cements and glass. Two theoretical analyses were investigated, namely, Hertzian indenter theory and integration of the Hondros diametral theory. Whilst both theories predicted the experimentally observed linear behaviour, neither were quantitatively correct. Furthermore, the Hondros theory contained an experimentally inaccessible parameter, the angle subtended by the contact width at the centre.