Ethics approval
The study protocol was conducted according to the principles of the Declaration of Helsinki and was approved by the local ethics committee (date 2019/01/23; No: 254/18) of the Medical Faculty of the University of Giessen. All participants provided informed written consent and were scheduled two different appointments between April 2019 and July 2019. The study had two objectives: the comparison of brushing as usual compared to the best of one’s abilities and the analysis of the stability of the brushing behavior within an interval of two weeks. The data presented here refer to the first objective.