Keywords: soft silicones; indications; wound healing.
Silicones are polymers (long-chains) with a structure that consists of alternate atoms of silicon and oxygen with organic groups attached to the silicon atoms. The degree of polymerisation determines the physical form of the silicone, which can vary from thin oils to relatively hard rubbers or resins.
Soft silicones are a particular family of solid silicones, which are soft and tacky. These properties enable them to adhere to dry surfaces.
A soft silicone dressing is a dressing coated with soft silicone as an adhesive or a wound contact layer. The intrinsic properties of soft silicone are such that these dressings may be removed without causing trauma to the wound or to the surrounding skin.
There are different types of soft silicone dressings including atraumatic wound contact layers, absorbent dressings for exuding wounds and also a dressing for the treatment of hypertrophic scars and keloids.
Soft silicone dressings are suitable for almost all indications where it is important to prevent trauma to the wound and the surrounding skin and pain to the patient. The different types of soft silicone dressings meet different clinical needs.
Silicones are chemically inert and adverse effects from the use of silicones in medicine and surgery are rare. Results of animal studies with silicones have shown they do not cause skin reactions or systemic toxicity. Soft silicone has been approved for use in wound management by regulatory bodies around the world.
Since silicone is inert, it does not interact chemically with the wound or have any effect upon the cells responsible for the healing process. Furthermore, because soft silicone dressings are easily removed, they do not traumatise the wound or the surrounding skin and therefore do not interfere with wound healing.
Soft silicone cannot enter the circulatory system. Silicone is insoluble in wound exudate and the silicone molecules are too big to penetrate through cell membranes or pass through the skin into blood vessels. They therefore cannot be transported around the body to produce any systemic effects.
Silicone is inert and less likely to cause sensitivity reactions than many other materials used in wound dressings. They are also widely used in consumer cosmetic products and as pressure sensitive adhesives in transdermal drug delivery systems.
Soft silicone is not intrinsically absorbent, but it can be applied as a facing layer to dressings containing absorbent components that are used for the management of exuding wounds.
Published studies suggest that patients whose wounds are dressed with soft silicone dressings experience less trauma, less discomfort on removal and less maceration than those dressed with conventional dressings, thus reducing treatment costs.
Soft silicone dressings are described as atraumatic dressings because in clinical studies it has been shown that they can be removed without causing trauma either to a wound or to the surrounding skin or pain to the patient.
Where there are clinical signs of infection the use of soft silicone dressings may be continued if appropriate antimicrobial treatment is initiated.
Some early reports suggest that soft silicone products may have a role in the treatment of the diabetic foot.
An international advisory group of scar management experts have recently published evidence-based clinical recommendations that support the use of silicone gel sheeting as a first-line therapy on immature, linear and widespread burn hypertrophic scars and minor keloids. Silicone gel sheeting should also be considered as a first-line prophylactic measure to help prevent the development of hypertrophic scars or keloids after surgery.
Numerous papers have been published describing the properties of silicone and the use of soft silicone dressings. These include:
Dahlstrom KK. A new silicone rubber dressing used as a temporary dressing before delayed split skin grafting. A randomised study. Scand J Plast Reconstr Surg Hand Surg 1995;29(4):325-27.
Dykes PJ, Heggie R, Hill SA. Effects of adhesive dressings on the stratum corneum of the skin. Journal Wound Care 2001; 10(2): 7-10.
Dykes PJ, Heggie R. The link between the peel force of adhesive dressings and subjective discomfort in volunteer subjects. Journal Wound Care 2003; 12(7): 260-62.
Gotschall CS, Morrison MI, Eichelberger MR. Prospective, randomized study of the efficacy of Mepitel on children with partial-thickness scalds. J Burn Care Rehabil 1998; 19(4): 279-83.
Mustoe TA, Cooter RD, Gold MH, Hobbs FDR, et al. International clinical recommendations on scar management. Plast Reconstr Surg 2002;110(2):560-71.
Platt AJ, Phipps A, Judkins K. A comparative study of silicone net dressing and paraffin gauze dressing in skin-grafted sites. Burns 1996; 22(7): 543-45.
Meaume S, Van De Looverbosch D, Heyman H, Romanelli M, Ciangherotti A, Charpin SA. Study to compare a new self-adherent soft silicone dressings with a self-adherent polymer dressing in Stage II pressure ulcers. Ostomy Wound Management 2003; 49(9):44-51.
Vloemans AF, Kreis RW. Fixation of skin grafts with a new silicone rubber dressing (Mepitel). Scand J Plast Reconstr Surg Hand Surg 1994; 28(1): 75-76.
Williams C. Mepitel. Br J Nurs 1995; 4(1): 51-52, 54-55.
Young M, Robbie J. Case studies: use of Mepitel and Mepilex. Management of the diabetic foot: a guide to the assessment and management of diabetic foot ulcers. The Diabetic Foot 2002; 5(3): Suppl.