2. Summary of meta‐analyses.
| Comparison | Studies | Outcome | Statistical method | Effect size | Chi2 | P value (Q) | I2 (%) |
| ADMG + CAF versus SCTG + CAF | Barros 2015; Joly 2007; Paolantonio 2002b; Shori 2013 | GR depth change | MD 95% CI | ‐0.36 (‐1.03, 0.30) | 15.06 | 0.002 | 80.0 |
| CAL change | MD 95% CI | ‐0.53 (‐1.14, 0.08) | 9.73 | 0.02 | 69.0 | ||
| KT width change | MD 95% CI | ‐0.59 (‐1.27, 0.10) | 17.17 | 0.0007 | 83.0 | ||
| SCRC | OR 95% CI | 0.43 (0.13, 1.37) | 0.00 | 0.96 | 0 | ||
| ADMG + CAF versus CAF | de Queiroz 2006; Woodyard 2004 | GR depth change | MD 95% CI | 0.61 (‐0.52, 1.73) | 7.45 | 0.006 | 87.0 |
| CAL change | MD 95% CI | 0.51 (‐0.25, 1.27) | 2.32 | 0.13 | 57.0 | ||
| KT width change | MD 95% CI | 0.28 (‐0.08, 0.64) | 0.30 | 0.59 | 0 | ||
| SCRC | OR 95% CI | 3.97 (0.20, 80.50) | 5.03 | 0.02 | 80.0 | ||
| EMP + CAF versus CAF (1) | Del Pizzo 2005; Sangiorgio 2017; Spahr 2005 | GR depth change | MD 95% CI | 0.07 (‐0.25, 0.40) | 5.62 | 0.06 | 64.0 |
| CAL change | MD 95% CI | 0.22 (‐0.02, 0.45) | 1.57 | 0.46 | 0 | ||
| KT width change | MD 95% CI | 0.35 (0.13, 0.56) | 0.64 | 0.73 | 0 | ||
| EMP + CAF versus CAF (2) | Del Pizzo 2005; Sangiorgio 2017; Spahr 2005 | GR depth change | MD 95% CI | 0.32 (0.10, 0.55) | 2.10 | 0.35 | 5.0 |
| CAL change | MD 95% CI | 0.35 (0.09, 0.61) | 1.25 | 0.53 | 0 | ||
| KT width change | MD 95% CI | 0.40 (0.17, 0.62) | 1.63 | 0.44 | 0 | ||
| EMP + CAF versus SCTG + CAF | Abolfazli 2009; McGuire 2012 | GR depth change | MD 95% CI | ‐0.39 (‐1.27, 0.48) | 25.79 | <0.00001 | 96.0 |
| CAL change | MD 95% CI | ‐0.25 (‐0.69, 0.20) | 2.95 | 0.09 | 66.0 | ||
| KT width change | MD 95% CI | ‐1.06 (‐1.36, ‐0.76) | 2.47 | 0.12 | 59.0 | ||
| SCRC | OR 95% CI | 0.61 (0.05, 7.86) | 7.86 | 0.005 | 87.0 | ||
| GTR rm + CAF versus SCTG + CAF | Paolantonio 2002; Wang 2001; Zucchelli 1998 | GR depth change | MD 95% CI | ‐0.37 (‐0.60, ‐0.13) | 0.25 | 0.88 | 0 |
| CAL change | MD 95% CI | 0.35 (0.06, 0.63) | 0.93 | 0.63 | 0 | ||
| KT width change | MD 95% CI | ‐1.77 (‐2.66, ‐0.89) | 15.84 | 0.0004 | 87.0 | ||
| SCRC | OR 95% CI | 0.61 (0.30, 1.24) | 2.01 | 0.37 | 0 | ||
| GTR rm + CAF versus GTR nrm + CAF | Roccuzzo 1996; Zucchelli 1998 | GR depth change | MD 95% CI | 0.23 (‐0.22, 0.68) | 1.59 | 0.21 | 37.0 |
| CAL change | MD 95% CI | 0.12 (‐0.37, 0.60) | 0.28 | 0.60 | 0 | ||
| KT width change | MD 95% CI | 0.12 (‐0.23, 0.48) | 0.03 | 0.86 | 0 | ||
| SCRC | OR 95% CI | 1.33 (0.46, 3.85) | 0.21 | 0.65 | 0 | ||
| GTR rm associated with bone substitutes + CAF versus SCTG + CAF | Paolantonio 2002; Rosetti 2000 | GR depth change | MD 95% CI | ‐0.82 (‐2.13, 0.49) | 9.92 | 0.002 | 90.0 |
| CAL change | MD 95% CI | ‐0.52 (‐1.34, 0.30) | 2.72 | 0.10 | 63.0 | ||
| KT width change | MD 95% CI | ‐2.38 (‐2.84, ‐1.92) | 1.86 | 0.17 | 46.0 | ||
| GTR rm associated with bone substitutes + CAF versus GTR rm + CAF | Dodge 2000; Paolantonio 2002 | GR depth change | MD 95% CI | 0.48 (0.09, 0.88) | 0.10 | 0.76 | 0 |
| CAL change | MD 95% CI | 0.76 (‐0.01, 1.54) | 2.83 | 0.09 | 65.0 | ||
| KT width change | MD 95% CI | 0.23 (‐0.21, 0.68) | 1.63 | 0.20 | 39.0 | ||
| SCRC | OR 95% CI | 1.87 (0.75, 4.64) | 0.03 | 0.87 | 0 | ||
| XCM + CAF versus CAF | Jepsen 2013; Sangiorgio 2017 | GR depth change | MD 95% CI | 0.40 (0.11, 0.68) | 0.86 | 0.35 | 0 |
| CAL change | MD 95% CI | 0.37 (‐0.09, 0.83) | 1.70 | 0.19 | 41.0 | ||
| KT width change | MD 95% CI | 0.44 (0.04, 0.85) | 1.16 | 0.28 | 14.0 | ||
| SCRC | OR 95% CI | 4.73 (2.35, 9.50) | 0.16 | 0.69 | 0 | ||
| PRF + CAF versus SCTG + CAF | Tunali 2015; Öncü 2017 | GR depth change | MD 95% CI | ‐0.01 (‐0.89, 0.86) | 14.71 | 0.0001 | 93.0 |
| CAL change | MD 95% CI | ‐0.37 (‐0.69, ‐0.06) | 0.58 | 0.45 | 0 | ||
| KT width change | MD 95% CI | ‐0.26 (‐0.98, 0.45) | 13.41 | 0.0003 | 93.0 |
ADMG: acellular dermal matrix graft; CAF: coronally advanced flap; CAL: clinical attachment level; CI: confidence interval; EMP: enamel matrix protein; GR: gingival recession; GTR rm: guided tissue regeneration resorbable membrane; GTR nrm: guided tissue regeneration non‐resorbable membrane; KT: keratinized tissue; MD: mean difference; OR: odds ratio; PRF: platelet‐rich fibrin; RR: risk ratio; SCRC: sites with complete root coverage; SCTG: subepithelial connective tissue graft; XCM: xenogeneic collagen matrix.