Non-absorbable Sutures

Materials	Polyamide  (Nylon)	Silk	Polypropylene (eg. prolene)	Polyester (eg. Mersilene)
Types	*monofilaments	2 types of fine silk sutures: *virgin silk  (fibrin coated by sericin) *braided silk  (degummed ie sericin is removed)  Both are multifilaments	*monofilaments    also available as *multifilaments	*monofilaments
Tissue reaction	*minimal	*moderate	*minimal	*minimal
Tensile strength	*high, losing 10 to 15% of  strength per year	*moderate, lasting 3 to 6 months	*high, maintain strength  for over 2 years	*high, permanent
Other characteristics	*mild elasticity *stiff suture ends which     must be buried to avoid     irritation	*inelastic *suture ends soft and     therefore  well-tolerated	*most elastic suture materials *stiff suture ends and irritate     if not buried	*strongest monofilament    and less elasticity than  other monofilaments
Indications	*most widely suture for   corneal wound sutures	*rarely used to close corneal   wound sutures but often   used as stay sutures.	* used mainly in iris repair    and intraocular lens fixation	*prefer by some surgeons   for its low elasticity and   high tensile strength

   Advantages of monofilament over multifilament :
   1. monofilament provides easy passage through the tissue whereas multifilament tend sto provide tissue drag
   2. the smooth surface of monofilament does not support bacterial growth whereas multifilament provide a nidus for infection

magnified view of monofilament magnified view of multifilament