Festa 2013.

Methods	Trial design: randomised, split‐mouth trial Location: Naples, Italy Number of centres: Stomatology Department, Second University of Naples (SUN), Naples, Italy Recruitment period: June 2008 to March 2010 Funding source: unclear
Participants	Inclusion criteria: Over 18 years of age Require double extraction of contralateral premolars located in symmetrical quadrants of maxillary or mandibular arches and requested an implant restoration All extraction sites had adjacent teeth Exclusion criteria: Systemic diseases that affect the periodontium or that contraindicate surgical treatment Long‐term NSAID therapy Failure to sign an informed consent Smoking Pregnancy or lactating period Buccal or palatal/lingual bony wall fractured or completely lost during the extraction procedure Age at baseline: range 28 to 58 years Gender: M6/F9 Smokers: none Teeth extracted: premolars Number randomised (participants/sites): 15/30 Number evaluated (participants/sites): 15/30
Interventions	Comparison: ARP (grafting material) versus extraction alone Test group (n = 15 extraction sockets). Corticocancellous porcine bone xenograft (Osteobiol Gen‐Os) (mixed granules with a diameter ranging from 250 to 1000 μm + soft cortical membrane (OsteoBiol Lamina) Control group: (n = 15 extraction sockets) extraction alone Surgical technique: flap, primary closure Type of the socket: four‐wall socket Duration of follow‐up: 6 months
Outcomes	Height and width of alveolar ridge
Notes	Sample size calculation
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Reported in the article “The test and control sites were randomly selected using a coin toss”
Allocation concealment (selection bias)	Unclear risk	No information in the article and the authors did not provide further information
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information in the article and the authors did not provide further information
Incomplete outcome data (attrition bias) All outcomes	Low risk	All data presented
Selective reporting (reporting bias)	Low risk	All outcomes appear to be detected
Other bias	Low risk	None detected