ABSTRACTThe sensory mechanisms underlying oral perception of hardness of silicone elastomers was studied using three approaches: (1) compression between parallel plates up to 10% (2) Bite forces of 10 subjects for hardness comparisons. (3) Deformations were evaluated during controlled mechanical indentations corresponding to the maximum force previously recorded. Over the mechanical stress range studied, the bite forces remained constant for soft samples and then increased for hard ones, while the resulting deformation followed an opposite variation with a decrease for soft samples and a plateau for hard ones. When considering the hardness comparisons between samples of a given series, the harder sample was detected in 10 pairs out of 17. This detection was obtained under almost constant bite force which shows that deformation should be the sensory clue for hardness perception.