Bacterial adherence to silk and expanded polytatrafluorethilene sutures: an in vivo human study

After oral surgery, bacterial adhesion to suture can cause surgical site infections and delay wound healing. Microbial adherence to the suture is influenced by its physical configuration and chemical structure. The aim of this study was to compare in vivo the bacterial adhesion to two suture materials used in oral surgery: silk and monofilament expanded polytetrafluoethilene (e-PTFE). After sinus lift surgery, 15 flaps were sutured with silk (nonabsorbable, organic, braided, 4.0) and 15 were sutured with e-PTFE (nonabsorbable, synthetic, monofilament, 4.0). Seven days after surgery, bacterial adherence, in terms of percentage of the surface covered, was evaluated for each suture material by scanning electron microscope (SEM). Onto silk suture, plaque consisted of a few cocci and a higher proportion of rods and filamentous-shaped bacteria, with some mineralized plaque. Onto e-PTFE speciments, only small colonies of a few cocci or no bacteria were observed, with empty spaces between the colonies and no plaque mineralization. The surface covered by bacteria on e-PTFE specimens was significantly lower than that of silk sutures. (22.1% ±4.96% vs 54.3% ± 7.9%; P =0.0001). The results of the present study suggest that multifilament structure of silk favours a greater bacterial adherence, proliferation, and persistence, so monofilament and e- PTFE suture should be preferred in oral surgery.