Funding for this research was provided by:
Research Center for Caries Prevention, Dental Research Institute, Tehran University of Medical Sciences (95-02-194-31632)
Received: 2 February 2019
Accepted: 13 September 2019
First Online: 22 October 2019
Ethics approval and consent to participate
: All participants gave informed written consent with the right to withdraw at any time. In the first part of the questionnaire, there was a paragraph introducing the study aim and assuring confidentiality of data by anonymous questionnaires. The Research Ethics Committee of Tehran University of Medical Sciences approved the study with code of IR.TUMS.VCR.REC.1395.1128.
: Not applicable.
: The authors declare that they have no competing interests.