Table 2.

Details Characteristics of each SR included in this Study

Part I
Authors	Year	Journal	Was the systematic review standardized?	Databases/sources	Goal	AMSTAR2 rating
Amine et al.	2017	J Stomatol Oral Maxillofac Surg	PRISMA statement. The present manuscript was written according to PRISMA checklist	MEDLINE (PubMed), Cochrane, and EBSCO	Assess the clinical efficacy of alternatives procedures; ADM, XCM, EMD, and PRF, compared to conventional procedures in the treatment of localized gingival recessions	Moderate
Castro et al.	2017	J Clin Periodontol	Guidelines of the Belgian CEBAM, Belgian branch of the Dutch Cochrane centre and the PRISMA statement; limited to studies involving humans; no language or time restrictions; only studies in English; no follow-up limitations	MEDLINE/PubMed, EMBASE (Excerpta Medical Database by Elsevier), and Cochrane Central Register of Controlled Trials (CENTRAL), hand searches, citation screening, and expert recommendations	Study the beneficial effect of L-PRF used as sole filling material and as adjunct to conventional techniques in periodontal surgery	High
Chambrone and Tatakis	2015	J Periodontol	PRISMA, Cochrane collaboration, and check review checklists; without language restriction	MEDLINE, EMBASE, and hand search of any potential studies and the databases of four periodontal journals	Determine the best, practical way to treat patients with periodontal regeneration, as well as to prepare solid guidelines and treatment rationale to support decision-making for specific clinical scenarios	Moderate
Chambrone et al.	2019	J Periodontol	Not described in the text of the article. The authors referenced to other 3 articles*	Not described in the text of the article. The authors referenced to other 3 articles*	Evaluated the efficacy of different root coverage procedures in the treatment of single and multiple gingival recession	High
Del Fabbro et al.	2011	J Periodontol	Clinical trials involving human subjects, no language or time restriction was applied	MEDLINE, EMBASE, the Cochrane central register of controlled trials, and hand search	Determine whether the use of autologous platelet concentrates may affect the outcome of regenerative procedures for the treatment of periodontal defects and gingival recession	Moderate
Li et al.	2019	BioMed Research International	PRISMA; only English articles were included; only RCT	Medline, EMBASE, Cochrane Central Register of Controlled Trials, hand search of the following Periodontology journals, bibliographies of all selected articles and relevant reviews were also searched for missing articles. In addition, gray literature was obtained from Google Scholars (https://xue.glgoo.org/). Unpublished and ongoing trials were obtained from the trial registries (EU clinical trials Register: https://www.clinicaltrialsregister.eu)	Evaluate whether the three generations of APCs could provide additional effect to CAF for gingival recessions, thus to provide guidance to practitioners in their clinical work - only miller Class I and II	High
Luo et al.	2015	Journal of Oral Rehabilitation	Only RCTs with a follow-up ≥3 months,	MEDLINE, PUBMED, EMBASE, Cochrane central register of controlled trials, and hand search was carried out in the major international journals in the field of Periodontology	Evidence-based systematic review and meta-analysis was to figure out whether adjunctive use of platelet concentrates could affect the outcomes of regenerative procedures for the treatment of gingival recession	High
Moraschini and Barboza	2016	J Periodontol	PRISMA and AMSTAR guideline checklists; without restrictions on dates or language Registered in PROSPERO (CRD42015026444)	PubMed/MEDLINE, Cochrane Central register of controlled trials, Web of Science, EMBASE, manual searches of the following regular journals, Unpublished studies (gray literature) were identified by searching the open-GRAY database and the clinicaltrials.gov database, and references of the included studies (cross-referencing) were performed	Evaluate the effects of the use of PRF on the outcomes of the clinical treatments of patients with gingival recession	High
Valenzuela and Oliva	2014	Int J Odontostomatology/Not found	No language restrictions were applied	The Cochrane central register of controlled trials (CENTRAL; The Cochrane Library), MEDLINE (PubMed), EMBASE (via OVID), science citation index, Google scholar, and reference lists of the most relevant studies and engines search were checked for possible additional studies	Assess the regeneration efficacy of PRF in periodontal surgery	Moderate
Part II
Authors	Focused question	APC/PRF production (technique)	Groups	Number of studies included	Studies included in this SR/justification	Conclusions
Amine et al.	NR	NR	CAF CAF + EMD CAF + PRF CAF + CTG	18	Included: n=5/Included studies that applied PRF	SCTG is still the gold standard procedure (treatment of miller Class I and II recession-type defects) PRF studies have reported contradictory results Furthermore, a standardized protocol for the preparation of PRF membranes should be followed
Castro et al.	Does L-PRF promote periodontal wound healing during periodontal surgery compared to traditional techniques?	L-PRF (protocol 2700 RPM/12 min or 3000 RPM/10 min)	L-PRF (alone or associated to another biomaterial) versus CTG	24 for SR and 14 for meta-analysis	Included: n=9[33,34,35,36,37,38,39,40,41]/Nine articles were related to Periodontal plastic surgery via CAF, with or without connective tissue graft	Favorable effects on soft tissue healing and postoperative discomfort reduction were often reported when L-PRF was used Standardization of the protocol is needed to obtain an optimal effect of L-PRF in regenerative procedures Correct handling of L-PRF as well as the use of enough clots/membranes per surgical site might be crucial to obtain benefits from this technique This biomaterial can be taken into consideration due to its reported good biological effects, low costs, and ease of preparation
Chambrone and Tatakis	What is the efficacy/effectiveness of RC procedures by the degree of recession? Miller Class I and II Miller Class III or IV What is the anticipated success and attachment apparatus of RC enhancements with autogenous grafts compared with alternative methods and materials? What are the relative risks from a patient’s viewpoint with the different approaches to RC procedures?	NR	Part I: An overview of the base of SRs Part II: An alternative random-effects meta-analysis on mean percentage of RC and sites exhibiting complete RC Part III: An SR of nonrandomized trials exploring other conditions not extensively evaluated by previous SRs	Part I: 17 for SRs Parts II and III: 94 were assessed and 52 following for meta-analysis	Included: Part I, n=0 Articles observed but excluded (justification) n=15 - did not involve PRF membranes, n=2 - PRP [16,52] Included: PART II and III, n=4 Articles observed but excluded (justification) n=1 - PRP[53]; n=1 - fibrin glue[54]; n=1 - FFSS[55] - biomaterial existent before PRF/only studies that used PRF as type of treatment	Did not conclude about APC/PRF
Chambrone et al.	NR	NR	FGG, LPF, CAF, SCTG alone or in combination with LPF or CAF, CAF in association with allograft (e.g., ADMG, others), GTR (with resorbable or nonresorbable membranes), EMD, XCM or other biomaterial Similar procedures (e.g., CAF with vertical incisions versus MCAF, without vertical incisions, etc.)	48 for SR and 20 for meta-analysis	Included: n=4 Articles observed but excluded (justification) 01 Keceli et al. - used PRP[56] 01 Trombelli et al. - used fibrin glue[54]/treatment of single or multiple miller’s Class I or II gingival recession (recession depth>3 mm), as well as at least 10 participants per group at final examination (with a follow-up<5 years	All RC procedures led to RD reduction and CAL gain The available evidence base indicates that the most suitable options for RC of GR, in terms of clinical outcomes and cost-to-benefit ratio, are: SCTG + CAF (gold standard); ADMG plus CAF; EMD + CAF; XCM + CAF; and CAF alone Moreover, evidence suggests that SCTG promoted better stability of the gingival margin/some degree of creeping attachment over time, compared to other surgical approaches The incidence of adverse effects, such as discomfort with or without pain, was mainly related to donor sites of SCTG. However, these conditions occurred mainly within the first week after surgery and did not influence on RC outcomes
Del Fabbro et al.	NR	NR	NR	24 for SR and 14 for meta-analysis (6, treatment of GR)	Included: n=1 Article observed but excluded (justification) Platelet concentrates different of membrane structure (PRP or PCG, n=5)/only study that used PRF membrane in GR treatment	No significant benefit of platelet concentrates was found for gingival recession
Li et al.	GR that attained RC; Change in RD was expressed as a reduction in recession at the final evaluation	NR	NR	8 for SR and 8 for meta-analysis	Included: n=5 Article observed but excluded (justification) 3 excluded - PRP[53,56,57]/only APC/PRF in membrane type	We considered that PRF should be preferred for the treatment of Classes I and II gingival recessions Overall, the risk of bias of the articles included in APCs was high, and more low-risk and high-quality researches were needed
Luo et al.	Primary outcome variable was the change in gingival RD	NR	Platelet concentrates or placebos were used in certain regenerative procedures of gingival recessions	9 for SR and 9 for meta-analysis	Included: n=2 Article observed but excluded (justification) PRP [53,56,58,59]; PDGF[60,61]; PRF[62] - only KTW results/only concentrates in membrane-shaped with results of GR treatment	Indicated that the addition of platelet concentrates might exert a positive adjunctive effect in the treatment of gingival recession
Moraschini and Barboza	What are the effects of PRF membranes on the treatment of gingival recession?	3000 RPM×10 min or 2700 RPM×12 min	PRF + CAF CAF alone CTG + CAF	n=7	Included: n=7 [33,34,35,36,37,38,39]/compared the performances of PRF in patients with miller Class I or II gingival recession	PRF membranes did not improve the RC, or CAL in the treatment of miller Class I and II gingival recessions compared with the other treatment modalities
Valenzuela and Oliva	Autologous PRF for regeneration of soft tissues in the oral Efficacy for soft tissue considered the outcome of mean gain of PD and mean gain of clinical attachment level	NR	PRF + CAF (test) CTG + CAF (Control)	11 RCT for SR; 6 for meta-analysis	Included: n=1[35] Article observed but excluded (justification) 1 study compared PRF with PRF + BPBM and it had not control group[63] did not have the mean change[34]/Only one was related to gingival recession; other were about intrabone defects (4) and furcation (1)	The regeneration efficacy of PRF in periodontal surgery is effective according to present information of RCT

*(a) Chambrone L, Salinas Ortega MA, Sukekava F, Rotundo R, Kalemaj Z, Buti J, et al. Root coverage procedures for treating localised and multiple recession-type defects. Cochrane Database Syst Rev 2018;10:CD007161; (b) Chambrone L, Sukekava F, Araújo MG, Pustiglioni FE, Chambrone LA, Lima LA. Root coverage procedures for the treatment of localised recession-type defects. Cochrane Database Syst Rev 2009;2:CD007161; (c) Chambrone L, Sukekava F, Araújo MG, Pustiglioni FE, Chambrone LA, Lima LA. Root-coverage procedures for the treatment of localized recession-type defects: A Cochrane systematic review. J Periodontol 2010;81:452-78. CEBAM – Centre for Evidence-Based Medicine; EMBASE – Excerpta Medica Database; MEDLINE – Medical Literature Analysis and Retrieval System Online; RCT – Randomized controlled trials; AMSTAR – Assessment of Multiple Systematic Reviews; RC – Root coverage; FFSS – Fibrin-fibronectin sealing system; ADM – Acellular dermal matrix; APC – Autologous platelet concentrate; CAF – Coronally advanced flap; EMD – Enamel matrix derivates; L-PRF – Leukocyte and platelet-rich fibrin; PRF – Platelet-rich fibrin; PRISMA – Preferred Reporting Items for Systematic Reviews and Meta-Analyses; XCM – Xenogeneic collagen matrix; BPBM – bovine porous bone mineral; CTG – Connective tissue graft; EU – European Union; FGG – Free gingival grafts; GTR – Guided tissue regeneration; GR – Gingival Recession; IF – Impact Factor; KTW – Keratinized tissue width; LPF – Laterally positioned flap; MCAF – Modified-coronally advanced flap; PD – Probing depth; RD – Recession depth; RPM – Revolutions per minute; SCTG – Subepithelial connective tissue graft; SR – Systematic review; NR – Not Reported; n – number; ADMG – Acellular dermal matrix graft; PRP – Platelet-Rich Plasm; CAL – Clinical attachment level; PCG – Platelet concentrates graft; PDGF – Platelet-derived growth factors;