Gingival phenotype changes after different periodontal plastic surgical techniques: a single-masked randomized controlled clinical trial

Objectives: Aim of this clinical study was to evaluate the effects on gingival thickness of three surgical techniques for root coverage: the coronally advanced flap (CAF) alone, with a sub-epithelial connective tissue graft (SCTG) or with leukocyte- and platelet-rich fibrin (L-PRF) membranes. Methods: Sixty patients with RT1 single maxillary gingival recession were treated with CAF + L-PRF (20 patients), CAF + SCTG (20 patients) or CAF alone (20 patients). At baseline and 6-month after treatment, gingival thickness (GT), keratinized tissue width (KT), gingival recession (GR), clinical attachment level (CAL), probing depth (PD), PROMs, and the aesthetic outcome were recorded. Results: CAF + SCTG and CAF + L-PRF groups showed a significantly greater mean GT increase than CAF alone (0.31 ± 0.10 mm) with no significant differences between CAF + SCTG (0.99 ± 0.02 mm) and CAF + L-PRF (0.92 ± 0.52 mm) groups (p = 0.55). CAF + SCTG was associated with a significantly greater KT gain (3.85 ± 1.04 mm), while in CAF + L-PRF (2.03 ± 0.53 mm) and CAF (1.50 ± 0.69 mm) groups, KT was not significantly increased. Both GR and CAL showed a significant within groups’ improvement, without among-groups differences. No significant among-groups difference for the aesthetic outcome but greater discomfort and pain-killer consumption in CAF + SCTG group was detected. Conclusion: All investigated surgical techniques produced significant GR reduction and CAL gain. GT was similarly augmented by CAF + L-PRF and CAF + SCTG techniques; however, the CAF + SCTG technique produced a more predictable KT and GT increase. Clinical relevance: The results of our study suggest that the CAF + SCTG technique represents the most predictable method for the clinician to improve the gingival phenotype, an important factor for long term gingival margin stability.