Text and Data Mining valid from 2018-10-05
Received: 1 November 2017
Accepted: 28 September 2018
First Online: 5 October 2018
Ethics approval and consent to participate
: This study was approved by the Ethics Committee at the Kyung Hee University Dental Hospital (KHD IRB 1603–4).
: Not applicable.
: The authors declare, that they have no competing interests.
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