This is the peer reviewed version of the following article: Akcalı A, Trullenque-Eriksson A, Sun C, Petrie A, Nibali L, Donos N. What is the effect of soft tissue thickness on crestal bone loss around dental implants? A systematic review. Clin. Oral Impl. Res. 00, 2016, 1–8, which has been published in final form at http://dx.doi.org/10.1111/clr.12916. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.