Clinical outcomes of a peri-implant keratinized mucosa augmentation procedure using concentrated growth factor: a prospective case series.

BACKGROUND: Adequate keratinized mucosa around implants is crucial for maintaining peri-implant hard and soft tissue health. Concentrated growth factor (CGF), a novel platelet concentrate, has been widely applied to promote tissue regeneration and wound healing, which could also be effective in peri-implant keratinized mucosa augmentation. This prospective case series aimed to present the clinical outcomes of apically repositioned flap (ARF) combined with CGF and to provide histological evidence. METHODS: Patients with insufficient keratinized mucosa (< 2 mm) were included. ARF combined with CGF was performed to augment the keratinized mucosa. Changes in the keratinized mucosa width (KMW) and vestibular depth (VD) from surgery to 12 months were documented. The secondary endpoints included the mucosal thickness (MT), marginal bone loss (MBL), modified plaque index (mPI), bleeding on probing (BOP), and probing depth (PD). Additionally, two biopsy samples were collected to analyze their tissue morphology and keratin expression. RESULTS: Thirty patients with a mean age of 46.0 ± 13.4 years and a total of 48 implant sites were recruited for the study. The KMW increased significantly from 1.44 ± 0.54 mm to 5.04 ± 1.64 mm at 2 weeks and stabilized at 2.48 ± 0.80 mm over 1 year (p < 0.001). The VD improved from 4.46 ± 2.38 mm to 5.32 ± 1.93 mm at 1-year post-ARF (p < 0.001). The MT increased from 1.48 ± 0.48 mm to 2.45 ± 0.70 mm (p < 0.001). After 1 year, the mPI and BOP were 0.47 ± 0.93 and 0.17 ± 0.39, respectively. The PD and MBL were 2.39 ± 0.59 mm and 0.36 ± 0.24 mm, respectively. Histological evaluation confirmed a typical keratinized mucosal structure with appropriate expression of keratin 5 and 10. CONCLUSIONS: Within the limitations of this case series, our findings suggested that the use of ARF combined with CGF could be a reliable approach for keratinized mucosal augmentation and vestibular deepening. KMW achieved the clinically ideal value of more than 2 mm one year after surgery. Histological analysis revealed the formation of keratinized mucosa around the implants.