Tabriz University of Medical Sciences Journal of Dental Research, Dental Clinics, Dental Prospects 2008-210X 19 2 2025 06 30 Platelet-rich fibrin and concentrated growth factor in the treatment of immediate implants in teeth with periapical lesions: A clinical trial with two-year follow-up 89 96 10.34172/joddd.025.41670 EN Maryam Zohary https://orcid.org/0000-0002-4287-2806 Meysam Malekzadeh https://orcid.org/0000-0002-7015-9485 Ashkan Salari https://orcid.org/0000-0003-4504-5141 Amin Afzali https://orcid.org/0000-0003-4931-2235 Dina Maleki https://orcid.org/0000-0002-8492-618X Journal Article 10.34172/joddd.025.41670 2024 08 15 2025 04 08 Background. This study was designed to compare the effect of platelet-rich fibrin (PRF) and concentrated growth factor (CGF) on the immediate implants placed in previously infected sites. Methods. A total of 210 patients were included in this randomized clinical trial. The remaining tooth was extracted, and the periapical lesion was removed. Then, PRF and CGF were placed in the socket in the PRF and CGF groups, respectively. No intervention was performed in the control group. The implant was inserted and sutured. Postoperative pain was measured using VAS. Plaque index (PI), bleeding on probing (BOP), buccal and proximal gingival esthetic index (GEI-B and GEI-P), crestal bone level, periapical lesion size, and Implant Health Scale (IHS) were evaluated. Data were analyzed with SPSS 18 using one-way ANOVA, Tukey, and repeated measures test at 0.05 significance level. Results. The mean BOP and pain in each period were significantly higher in the control group than in the PRF and CGF groups and in the PRF group than in the CGF group (P=0.001 and P<0.001). In the PRF, CGF, and control groups, pain had a decreasing trend (P=0.010, P<0.001, and P=0.001); PI had a significant increasing trend (P=0.034, P<0.001, and P<0.001); crestal bone level had a significant increasing trend (P=0.023, P=0.033, and P<0.001); and the size of periapical lesion had a significant decreasing trend (P=0.004, P=0.002, and P=0.048). The IHS showed optimum health after two years in the PRF and CGF groups. Optimum health, satisfactory survival, and compromised survival were reported in the control group. Conclusion. PRF and CGF guaranteed the successful osseointegration of immediate implants in previously infected sites. CGF and PRF positively affected the soft tissue and hard tissue around the immediate implants. CGF had more promising effects than PRF.