(b) Characteristics of the included studies

First Author (Year of Publication)	Outcomes	Follow-up	PRF Preparation technique	RBH (mm)
Nizam N, 2018	Primary outcomes: newly formed bone, residual bone graft, and newly formed bone-to-bone contact Secondary outcomes: clinical and radiographic data (6 months after augmentation; implant survival rate 12 months after implant loading)	12 months	A table centrifuge (Nüve Laboratory Equipment, NF200, Ankara, Turkey) or 12 min at 400 × g	Test: 2.45 ± 0.79 Control: 2.53± 0.61
Zhang Y, 2012	New bone formation: percentage of residual bone substitute contact length between newly formed bone and bone substitute	6 months	PRF by Choukroun's Procedure (300 g for 10 min)	< 5
Comert K S, 2017	Primary outcomes: new bone formation, mean percentages of residual graft particle area, percentages of soft tissue, and no postoperative maxillary sinus infection Secondary outcomes: mean densities of bone cells (osteoblasts, osteoclasts, osteocytes, and osteoprogenitors), capillary vessels, and inflammatory cells	Control group: 6.14±0.57 months; P-PRP group: 6.08±0.67 months; PRF group: 6.29±0.53 months	PRF by Choukroun's Procedure (3000 rpm for 10 min)	< 7
Tatullo M, 2012	New bone; complications; ISQ values (Implant Stability Quotient); bone density; clinical success rate	150 days	Choukroun's procedure	< 5
Gurler G, 2016	Healing Index (HI) scores Inflammatory and infectious reactions Patient comfort	14 days	Centrifuge (IntraSpin, USA) at 2700 rpm for 12 min	NA

RBH: residual bone height.