Connective tissue graft with injectable platelet rich fibrin for treatment of RT1 gingival recession by tunnel technique: a randomized clinical and immunohistochemical study

Objectives – The literature regarding the use of injectable platelet- rich fibrin (i-PRF) for root coverage is scarce. Therefore, this RCT aimed to evaluate and compare the effect of using connective tissue graft (CTG) with and without i-PRF using the tunnel technique for Cairo class 1 gingival recession (RT1) clinically and immunohistochemically. Methods – Thirty patients were randomly allocated into 2 groups. (a) CTG immersed in i-PRF (treatment group) and (b) CTG only (control group). The clinical outcomes were assessed at baseline and 6 months. Primary outcome measures were keratinized tissue height (KTH), recession depth (RD), mean root coverage (MRC) & complete root coverage (CRC). Secondary outcome measures were clinical attachment level (CAL), recession width (RW), gingival thickness (GT), probing depth (PD), and Visual analogue scale (VAS) for pain. The Immunohistochemical analysis of vascular endothelial growth factor A (VEGF A) and transforming growth factor beta 1 (TGFβ1) in CTG was done. Results – The primary outcomes analysis showed statistically significant improvements in KTH and RD at 6 months compared to baseline in both groups (p < 0.05). The test group showed significant improvement compared to the control group in 6 months follow up period regarding increased KTH, decreased RD, and MRC. The CRC showed no significant difference between the two groups. The secondary outcomes analysis showed statistically significant improvements in RW, GT, PD, and CAL in 6 months compared to baseline within each group (p < 0.05) with no difference between groups. VAS in the test group showed statistically significant improvement compared to the control group at one-week post-operative (p < 0.001). The immunohistochemical analysis showed that the CTG of the test group had significantly higher expression of VEGF A and TGFβ1 compared to the control group (p < 0.001). Conclusion – The use of CTG immersed in i-PRF with the tunnel technique for surgical management of RT1 multiple adjacent gingival recessions led to improved KTH, better RD reduction, better MRC and less post-operative pain. Additionally, CTG immersed in i-PRF showed higher expressions of VEGF A and TGFβ1 compared to CTG alone. Clinical Trial Registration: ClinicalTrials.gov, registration NCT06646432.