The character of a consent for treatment is not a mere hobby for lawyers; it also has consequences in daily practicein the Netherlands, particularly if it concerns questions of who should prove what in proceedings. In general, consent agreements can be divided into an obligation to achieve results and an obligation to use reasonable endeavours. In oral healthcare, there is usually a question of an obligation to use reasonable endeavours, in which professional standards must play a leading role in the behaviour of the dentist; and here there have been a number of recent developments, such as an increase in the number of (clinical) guidelines and the acceptance of wish fulfilling medicine, under strict conditions. It is concluded that recent developments in the dentist’s requirement to provide evidence in proceedings have definitely not made things simpler.