Influence of autogenous platelet concentrate on combined GTR/graft therapy in intra‐bony defects: A 13‐year follow‐up of a randomized controlled clinical split‐mouth study

Aim To investigate the clinical long‐term outcomes 13 years following guided tissue regeneration (GTR) in deep intra‐bony defects with and without additional application of autogenous platelet concentrate (APC). Methods In 25 patients, two deep contra‐lateral intra‐bony defects were treated according to GTR using β‐TCP and bio‐resorbable membranes. In test defects, APC was applied additionally. After 13 years, clinical healing results were assessed and compared to results at baseline and after 1 year. Furthermore, a tooth survival analysis was carried out. Results After 13 years, 22 patients were available for tooth survival analysis showing 81.8% of test and 86.4% of control teeth still in situ. Based on the 15 patients still available for split‐mouth analysis, median CAL was 10.0 mm in test and 12.0 mm in control sites at baseline. After 1 year, both groups revealed significant CAL gains of 5.0 mm, followed by a new CAL loss of 1.0 mm in the following 12 years. There were no significant differences between test and control sites. Conclusion Within the limits of this study, the data show that most of the CAL gain following GTR can be maintained over 13 years. The additional use of APC had no positive influence on the long‐term stability.