“…The present study investigated the long‐term healing outcomes 13 years after combined GTR/graft therapy with or without additional application of autogenous platelet concentrate. In general, studies reporting on long‐term outcomes after regenerative periodontal therapies are scarce (Wu et al., ). To date, there are only five prospective randomized clinical trials on GTR or combined GTR/graft therapy in intra‐bony defects with follow‐up for 10 years (Nickles, Ratka‐Krüger, Neukranz, Raetzke, & Eickholz, ; Nygaard‐Østby, Bakke, Nesdal, Susin, & Wikesjö, ; Pretzl, Kim, Holle, & Eickholz, ; Pretzl et al., ; Sculean, Kiss, et al., ) and only one very recent study on GTR with a longer observation period (i.e.…”