Zucchelli 1998.

Methods	RCT, parallel design, 3 treatment groups, 12 months' duration
Participants	54 individuals, 29 females, aged 23 to 33 years, with 1 Miller Class I or II buccal gingival recession of at least 3 mm
Interventions	1. GTR (polylactic acid membrane ‐ Guidor) 2. GTR (ePTFE membrane ‐ Gore‐Tex) 3. SCTG + CAF
Outcomes	GRC CALC KTC*(3) SCRC PCRC MRC (Manual probe)
Notes	University/hospital‐based
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method not reported
Allocation concealment (selection bias)	Unclear risk	Method not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Information not reported
Blinding of outcome assessment (detection bias) All outcomes	Low risk	All measurements were performed by 1 examiner not aware of the type of surgical procedure
Incomplete outcome data (attrition bias) All outcomes	Low risk	All patients completed the follow‐up period
Selective reporting (reporting bias)	Low risk	Evidence of selective reporting of outcomes was not detected
Other bias	Low risk	Evidence of other bias was not detected