Biologically guided flap stability: the role of flap thickness including periosteum retention on the performance of the coronally advanced flap–A double-blind randomized clinical trial

Aim: To evaluate the possible benefit on wound healing and flap stability of periosteum inclusion, comparing a “split–full–split” thickness flap elevation versus a “split” thickness approach performed during CAF for the treatment of isolated-type gingival recessions in the upper jaw. Material and Methods: Forty patients were randomized, 20 were treated with “split–full–split” (test group) and 20 with a “split” approach (control group). Analysed parameters at 1 year were CRC, percentage of recession coverage (RC), keratinized tissue (KT) gain and patient-related outcome measurements. Results: After 12 months, CRC was 80% in the test group and 35% in the control group. Percentages of RC and KT gain were higher in the test group, and a significant association between CRC and the thickness of the flap after elevation was found. Patient-related outcomes measurements were better for the test group. Conclusions: Flap thickness preservation and the presence of the periosteum in part of the flap may play a fundamental role in obtaining CRC.