Bertl K, Gotfredsen K, Jensen SS, Bruckmann C, Stavropoulos A. Can hyaluronan injections augment deficient papillae at implant-supported crowns in the anterior maxilla? A randomized controlled clinical trial with 6 months follow-up. Clinical Oral Implants Research. 2017 sep.;28(9):1054-1061. doi: 10.1111/clr.12917