Text and Data Mining valid from 2019-11-05
Received: 15 February 2019
Accepted: 6 September 2019
First Online: 5 November 2019
Compliance with ethical standards
: The study was approved by the Research Ethics Committee of Hospital of Stomatology, Hebei Medical University. This was a network meta-analysis which not required an informed consent.
: The authors declare that they have no conflicts of interest.