Serrano Mendez 2017.

Study characteristics
Methods	Trial design: randomised, parallel‐group trial Location: Bogota, Colombia Number of centres: single centre, National University of Colombia, Bogota, Colombia Recruitment period: April 2012 to October 2015 Funding source: this study was supported by grants from vice‐rectory for research (National University of Colombia), Colgate Palmolive (Colombia), Ariminum Research and Dental Education Centre (Rimini, Italy), and Clinical Research Foundation for the Promotion of Oral Health (Brienz, Switzerland)
Participants	Inclusion criteria: patients aged ≥ 18 years, required extraction of non‐molar tooth and committed to replacement with dental implant after 6 months; presence of at least 1 neighbouring tooth Exclusion criteria: any medication compromising healing; periodontitis; plaque score > 30%; loss of buccal bone at the time of extraction; pregnant women, smoking > 10 cigarettes per day Age at baseline: mean age of 44 years Gender: M 10/F 10 Smokers: 2 Teeth extracted: non‐molar teeth Number randomised (participants/sites): 20/20 Number evaluated (participants/sites): 20/20
Interventions	Comparison: ARP (grafting material) versus ARP (grafting material) Test group A: (n = 10 extraction sockets) demineralised freeze‐dried cortical bone allograft (DFDBA) (600 to 800 µm, Banco de Tejidos Cosme y Damian, Bogota, Colombia) + collagen barrier (Bio‐Gide, Geistlich Pharma AG, Wolhusen, Switzerland) Test group B: (n = 10 extraction sockets) deproteinised bovine bone mineral (DBBM) with 10% porcine collagen (Bio‐Oss Collagen, Geistlich Pharma AG, Wolhusen Switzerland) + collagen barrier (Bio‐Gide, Geistlich Pharma AG, Wolhusen, Switzerland) Surgical technique: flap, primary closure Type of socket: 4‐wall socket Duration of follow‐up: 6 months
Outcomes	Width and height of alveolar ridge, histomorphometric analysis Method of assessment: periodontal probe, caliper, standardised radiograph, template
Notes	Sample size calculation: reported The sample size was calculated with a power of 80% and an alpha level of 0.05. The calculations were based on previous literature and assumed a difference of 1 mm and standard deviation of 1.3 mm in ridge width. A total of 10 participants per group was required
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "A randomization table was created electronically in blocks of two patients"
Allocation concealment (selection bias)	Unclear risk	Insufficient information in the article
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quotes: "The clinical measurements were performed by a different person that was not involved in any other section of the treatments" and "The histological assessments were performed by an operator not involved in any of the other parts"
Incomplete outcome data (attrition bias) All outcomes	Low risk	All data presented
Selective reporting (reporting bias)	Low risk	All outcomes appear to be reported
Other bias	Low risk	None detected

ARP = alveolar ridge preservation; F = female; M = male; NSAID = non‐steroidal anti‐inflammatory drugs.