Funding for this research was provided by:
Received: 12 September 2018
Accepted: 20 February 2019
First Online: 7 March 2019
Ethics approval and consent to participate
: This study adhered to CONSORT guidelines and was conducted in accordance with the World Medical Association Helsinki Declaration (Version 2008). The study protocol was approved by each of the involved Institutional Review Boards (IRBs) at Kyung Hee University Dental Hospital (KHDIRB1409–2), Yonsei University Hospital (2014–0074), and Dankook University Hospital (H-1411/011/003). All the participants were informed of the objectives, interventions, and possible risks and benefits of the study prior to enrollment, and written consent was obtained.
: Not applicable.
: The authors declare that they have no competing interests.
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