Randomization and blinding
GN
RECRUITMENT
Sequence generation was executed using simple randomization by a computer-generated list from numbers 1:40 by an investigator (NM) who was not involved in recruitment nor treatment. Allocation concealment was implemented by the same investigator using sequentially numbered, opaque, sealed envelopes handled to the surgeon (GN) who did not open them until the beginning of the interventions. After pretreatment phase, eligible participants were randomly assigned into two parallel groups with a 1:1 allocation ratio to receive either SCTG following atraumatic extraction (test group) or minimally-traumatic extraction followed by spontaneous healing only (control group) based on the generated sequence. Due to the difference in the intervention’s techniques, both the operating surgeon and the participants could not be blinded to the procedure. The outcome assessor (SN) and statistician (GNA) were blinded.