What is silicone?
Silicones are inert synthetic polymers made up long chains of siloxanes. These contain silicon and other elements. Silicones have many industrial uses and can vary in form from oil, to rubber and hard resins.
Why use silicone for medical dressings?
The following specific properties make silicone useful for medical dressings:
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Safe
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Low thermal conductivity
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Low chemical reactivity
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Low toxicity – adverse reactions are rare as silicone cannot be absorbed into the body
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Repels water and forms a watertight seal
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Does not support microbial growth
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High gas permeability
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Adhesive to dry skin
How do silicone dressings work?
Soft silicone is a particular family of solid silicone that is soft and “tacky”. The tack of soft silicone means it can form a seal around a wound by creating multiple points of adherent skin contact. This is particularly useful to patients with fragile skin (eg epidermolysis bullosa and elderly patients).
Silicone has a stable and immediate adhesive profile unlike acrylic adhesives, which progressively become more adhesive with duration of application. The “tack” of silicone dressings is retained, allowing the dressing to be reapplied multiple times without loss of adhesion.
The hydrophobic property of silicone prevents adherence to moist wound bases, so it is relatively atraumatic.
Soft silicone dressings are designed to:
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Be comfortable
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Reduce pain and trauma of epidermal stripping during dressing changes
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Protect skin around the wound from contact with exudate
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Not adhere to moist surfaces
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Not leave a residue following removal
What types of silicone dressings are there?
Primary wound contact layers
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These are composed of a non-absorbent polyamide net
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Allow exudate to pass through to an absorbent dressing
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Useful for superficial wounds
Foam dressings with silicone adhesive
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Thin adhesive silicone layer that wicks fluid vertically
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Absorbent dressing
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Minimises exudate contact with periwound skin
Silicone gel sheets
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Thick sheet of silicone gel
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Does not require a secondary dressing
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Designed to be used on healed wounds
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Used to minimise hypertrophic/keloid scars
Reference to Author: Dr lan Logan