Strength characterization of alumina bioceramics according to the new ISO draft

In order to overcome the shortcomings of the usual bending test, in 1987 a new procedure for determining the strength was suggested in the revision draft of the ISO standard for alumina. This so-called concentric-ring-test exhibits several advantages: It is more sensitive and critical and distinguishes better between different surface treatments. This is demonstrated by measurements on two commercially available bioceramics.