Forty patients participated in this prospective, randomized, double-blind clinical trial. Vertical mattress sutures were used following resective periodontal surgery performed by one operator. Four suture materials were selected for evaluation: 5-0 silk; 5-0 polypropylene; 5-0 polyglycolic acid (PGA), and 4-0 polytetrafluoroethylene (PTFE). Seven days after the surgical procedure, the surgeon assessed suture loosening and removed the sutures. A blind researcher clinically evaluated erythema and edema.