Amirzargar, R., Shirani, G., Mahmoudhashemi, H., Khoshzaban, A. and Hasheminejad, M. 2018. A comparative study of ridge preservation using calcium sulfate and collagen membrane with and without freeze-dried bone allograft following tooth extraction. Journal of Osseointegration. 10, 1 (Mar. 2018), 11–16. DOI:https://doi.org/10.23805/jo.2018.10.01.02.