Received: 27 November 2019
Accepted: 28 January 2020
First Online: 7 February 2020
Ethics approval and consent to participate
: Ethical approval has been obtained from the Ethics Committee of the Faculty of Dental Medicine, Universitas Airlangga (KKEPK), Indonesia (permit number: 48/KKEPK.FKG/IV/2016), in accordance with the International Ethical Guidelines for Biomedical Research Involving Human Subjects by The Council for International Organizations of Medical Sciences (CIOMS).
: Not applicable.
: The authors declare that they have no competing interests.