Clinical relevance of laboratory studies on dental materials: strength determination--a personal view

The measurement of strength of materials is undertaken in a laboratory primarily to determine its relationship to the microstructural features of the material, as the understanding it brings will allow the production of stronger materials. Problems arise when attempts are made to derive some sort of clinical significance from these data without due regard to the functional aspects of the device from which the material is made. Three examples are presented which seek to highlight that: (1) strength, however desirable, is not necessarily the most important consideration; (2) great care has to be exercised in interpreting strength data; and (3) the most appropriate properties are considered for each individual dental application of the material.