1. Search results.
| Database | First search date | Records retrieved (excl. duplicates) | Top‐up search | Records retrieved (excl. duplicates) | Top‐up search | Records retrieved (excl. duplicates) |
| Cochrane Oral Health Trials' Register | 31 July 2013 | 567 | 27 January 2015 | 123 | 18 January 2016 | 51 |
| CENTRAL via the Cochrane Library | 31 July 2013 | 164 | 27 January 2015 | 29 | 18 January 2016 | 10 |
| MEDLINE via OVID | 31 July 2013 | 509 (with RCT filter) | 27 January 2015 | 42 (with RCT filter) | 18 January 2016 | 33 (with filter) |
| Embase via OVID | 31 July 2013 | 214 (with RCT filter) | 27 January 2015 | 51 (with RCT filter) | 18 January 2016 | 18 (with filter) |
| CINAHL via EBSCO | 31 July 2013 | 94 (with RCT filter) | 27 January 2015 | 11 (with RCT filter) | 18 January 2016 | 8 (with filter) |
| Web of Science Conference Proceedings | 31 July 2013 | 151 | 27 January 2015 | 6 | 18 January 2016 | 3 |
| ClinicalTrials.gov | 31 July 2013 | 22 | 27 January 2015 | 23 | 18 January 2016 | 24 |
| WHO International Clinical Trials Registry Platform | Not performed | ‐ | 27 January 2015 | 3 | 18 January 2016 | 0 |
RCT: randomised controlled trial WHO: World Health Organization