A comparison between the diametral and double-punch testing of a dental gypsum

The tensile strength of a dental gypsum was measured indirectly using both the diametral and the double-punch tests. Observed differences between the effects of specimens size on the diametral and double-punch strengths could be consistently interpreted in terms of the statistical theory of brittle fracture. The double-punch test, when compared with the diametral test, has several important advantages. These advantages include less experimental scatter, a weaker dependence of the measured strength on the specimen size and a simpler testing procedure.