Accepted: 8 January 2016
First Online: 12 February 2016
Change Date: 12 December 2017
Change Type: Update
Change Details: The digital object identifier (DOI) number associated with this article was incorrect in the PDF version of the article in the original issue as published on the 12 February 2016. The correct DOI is 10.1038/sj.bdj.2016.94. We apologise for any inconvenience caused by this error.
: This study and writing support for the manuscript were funded by Wrigley Oral Healthcare Programme.