Funding for this research was provided by:
Jiangsu Provinicial medical youth talent (QNRC2016391)
Text and Data Mining valid from 2018-05-10
Received: 5 July 2017
Accepted: 1 May 2018
First Online: 10 May 2018
Ethics approval and consent to participate
: Ethics approval was obtained from the Ethics Committee of Affiliated Stomatology Hospital of Nanjing Medical University and written consent of the participants whose premolars were used in the study was given.
: The authors declare that they have no competing interests.
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