Study	Reason for exclusion
Abdelhamid 2016	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Aimetti 2009	The study followed up participants for less than 6 months
Aimetti 2018	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Alkan 2013	A histological study
Alkanan 2019	The study followed up participants for less than 6 months
Al Qabbani 2018	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Amirzargar 2018	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Araujo 2015	The study followed up participants for less than 6 months
Arbab 2016	The study followed up participants for less than 6 months
Areewong 2019	The study followed up participants for less than 6 months
Bakhshalian 2018	A histological and histomorphometrical study
Barone 2013	A histological study
Barone 2015	A histological and histomorphometrical study
Barone 2016	The study followed up participants for less than 6 months
Barone 2017	The study followed up participants for less than 6 months
Borg 2015	The study followed up participants for less than 6 months
Calasans‐Maia 2013	A histological and histomorphometrical study
Canellas 2020	The study followed up participants for less than 6 months
Cardaropoli 2012	The study followed up participants for less than 6 months
Cardaropoli 2014	The study followed up participants for less than 6 months
Casado 2010	The study is not a randomised controlled trial
Cavdar 2017	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Checchi 2011	A histological and histomorphometrical study
Clark 2018	The study followed up participants for less than 6 months
Clementini 2020	The study followed up participants for less than 6 months
Cook 2013	The study followed up participants for less than 6 months
Coomes 2014	The study followed up participants for less than 6 months
Corning 2019	The study followed up participants for less than 6 months
Crespi 2009	The study is not a randomised controlled trial
Debel 2021	The study only reported the soft tissue volumetric changes
Demetter 2017	The study followed up participants for less than 6 months
Eskow 2014	The study followed up participants for less than 6 months
Fernandes 2016	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Fiorellini 2005	The study followed up participants for less than 6 months
Flugge 2015	The study only reported the soft tissue volumetric changes
Fotek 2009	The study followed up participants for less than 6 months
Froum 2002	A histological study
Geurs 2014	A histological and histomorphometrical study
Girish Kumar 2018	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Guarnieri 2017	The study followed up participants for less than 6 months
Hassan 2017	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Hauser 2013	The study followed up participants for less than 6 months
Iasella 2003	The study followed up some participants for less than 6 months. Some of the data were recorded at 4 months
Jo 2019	The study followed up participants for less than 6 months
Jonker 2020	The study followed up participants for less than 6 months
Jung 2013	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Jung 2018	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Karaca 2015	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Kim 2011	The study is not a randomised controlled trial
Kim 2014	The study followed up participants for less than 6 months
Kotsakis 2014	The study followed up participants for less than 6 months
Kutkut 2012	The study followed up participants for less than 6 months
Lai 2020	The study followed up participants for less than 6 months
Lee 2020	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Lekovic 1997	The study is not a randomised controlled trial
Lekovic 1998	The study followed up participants for less than 6 months
Lim 2017	The study followed up participants for less than 6 months
Lim 2019	The study followed up participants for less than 6 months
Llanos 2019	The study followed up participants for less than 6 months
Machtei 2019	The study followed up participants for less than 6 months
Mandarino 2018	The study followed up participants for less than 6 months
Marconcini 2018	The study followed up participants for less than 6 months
Mayer 2016	The study followed up participants for less than 6 months
Meloni 2015	The study followed up participants for less than 6 months
Molly 2008	A histological study
Nart 2017	The study followed up participants for less than 6 months
Natto 2017	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Neiva 2011	The study is not a randomised controlled trial
Nevins 2006	The study followed up participants for less than 6 months
Nevins 2011	A histological and histomorphometrical study
Oghli 2010	The study followed up participants for less than 6 months
Ouyyamwongs 2019	The study followed up participants for less than 6 months
Ovcharenko 2020	The study followed up participants for less than 6 months
Parashis 2016	The study followed up participants for less than 6 months
Pelegrine 2010	There were serious doubts if the study was actually a randomised controlled trial and the authors did not answer back and clarified the doubts
Pellegrini 2014	A histological and histomorphometrical study
Perelman‐Karmon 2012	A histological and histomorphometrical study
Pinho 2006	The study followed up participants for less than 6 months
Poulias 2013	The study followed up participants for less than 6 months
Rasperini 2010	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Sbordone 2017	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Scheyer 2012	A histological study
Schneider 2014	The study only reported the soft tissue volumetric changes
Serino 2003	The study is not a randomised controlled trial
Shakibaie 2013	The study is not a randomised controlled trial
Shim 2018	The study is not a randomised controlled trial
Sisti 2012	The study followed up participants for less than 6 months
Spinato 2014	The study followed up participants for less than 6 months
Sun 2019	The study followed up participants for less than 6 months
Temmerman 2016	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Thalmair 2013	The study only reported the soft tissue volumetric changes
Toloue 2012	The study followed up participants for less than 6 months
Vance 2004	The study followed up participants for less than 6 months
Walker 2017	The study followed up participants for less than 6 months
Wood 2012	The study followed up participants for less than 6 months
Zadeh 2016	Unclear whether alveolar ridge preservation was used for participants requiring implant‐related prosthodontic treatment
Zhao 2018	The study is not a randomised controlled trial