Rayon is obtained from the wood of the spruce tree. The timber is freed from the bark. It is treated chemically to remove resins, washed and bleached. This mass of white fibers is converted into alkali cellulose by maceration with caustic soda. This is shredded, further soaked in alkali and shredded into crumbs. It is then…
Cellulose wadding is prepared from timber (usually pine). The wood is disintegrated to separate the fibers. It is then treated to remove the lignin and bleached to obtain a white product. It is then compressed into sheets and rolled. Uses: This is used as an absorbent and protective either alone or in combination with other materials…
Wool consists of the hairs from the fleece of the sheep Ovis aries. The hairs are coated with wool fat. It is removed by kneading in water, where the fat gets emulsified with water. This process also helps in washing other impurities. It is marketed as yellowish-white, continuous, slightly twisted and coherent pieces. It is highly hygroscopic…
The most common fiber used in surgical dressings is cotton. Regenerated cellulose, wood fibers and wool are also used. Cotton also forms the basis for most of the surgical dressings such as gauze, lint, bandages and plasters. Absorbent Cotton Wool (Gossypium Absorbens; Syn. Absorbent Cotton, Absorbent Wool) Learning Objectives Cotton is obtained from the epidermal trichomes…
Learning Objective The dressings may be classified into the following types:
Learning Objective Surgical dressings are mainly applied on the skin in case of injury or wounds. During any damage to the skin, the wound gets plugged with a blood clot, which is a form of natural first aid that prevents any further loss of blood or damage to the injured part. The skin is then…
Stainless steel sutures are available in monofilament, braided or twisted forms. They are made of fully softened stainless steel wire. They are nonirritant, have high tensile strength in fine gauge and are found useful in plastic and orthopedic surgeries. They are readily sterilized.
Polyester fibers are synthetic braided nonabsorbable sutures that do not lose strength upon contact with water or other body fluids. They do not contain wax or other additives and have excellent knot-holding properties. They are available in the natural color or dyed to enhance visibility in the surgical field. Coated polyester fibers are available, which…
Nylon Synthetic sutures consist of nylon fibers made from nonabsorbable (i.e., nonbiodegradable) aliphatic (e.g., polyamide 6) polymers. These sutures are typically available in sterile coated thread sections (e.g., 18, 30 inches/45, 76 cm long) attached to a single-use needle as an integral device and they are frequently colored for easy identification during surgery. Nylon sutures…
Learning Objective Natural Nonabsorbable Sutures Silk The most common nonabsorbable suture is a natural fiber, silk, which undergoes a special manufacturing process to make it adequate for its use in surgery. Natural silk surgical suture is a nonabsorbable, sterile, flexible multifilament thread composed of an organic protein called fibroin. Silk sutures are made of raw…