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:
- Safe
- Low thermal conductivity
- Low chemical reactivity
- Low toxicity – adverse reactions are rare as silicone cannot be absorbed into the body
- Repels water and forms a watertight seal
- Does not support microbial growth
- High gas permeability
- Adhesive to dry skin
However:
- The cost of silicone dressings may limit their use.
- There is lack of strong evidence of effectiveness for established scar reduction or prophylaxis against hypertrophic or keloid scars,
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:
- Be comfortable
- Reduce pain and trauma of epidermal stripping during dressing changes
- Protect skin around the wound from contact with exudate
- Not adhere to moist surfaces
- Not leave a residue following removal
What types of silicone dressings are there?
Primary wound contact layers
- These are composed of a non-absorbent polyamide net
- Allow exudate to pass through to an absorbent dressing
- Useful for superficial wounds
Foam dressings with silicone adhesive
- Thin adhesive silicone layer that wicks fluid vertically
- Absorbent dressing
- Minimises exudate contact with periwound skin
Silicone gel sheets
- Thick sheet of silicone gel
- Does not require a secondary dressing
- Designed to be used on healed wounds
- Used to minimise hypertrophic/keloid scars
Silicone wound dressings
Silicone dressing types and uses*
Absorbent dressings
The properties of absorbent dressings such as Eclypse® adherent, Episil® absorbent include:
- High capacity exudate absorption
- Atraumatic dressings
- Breathable fluid repellent backing
- Moist wound healing environment
They are recommended for:
- Highly exudative wounds
- Topics /Silicone dressings
- Pressure sores
- Sloughy or granulating wounds
- Postoperative sutured or dehisced wounds
- Fungating wounds
- Skin graft donor sites
Foam with silicone adhesive
The properties of foam dressings such as Advazorb® border, 3M Tegaderm®, Allevyn® Gentle border include:
- Absorbs fluid and retains it within the dressing promoting a moist wound healing environment
- Hydrophilic foam bacterial barrier
- High breathability
They are recommended for
- Low-high exudative wounds
- Leg ulcers
- Pressure sores
- Cuts and abrasions
- Surgical wounds
- Minor thermal burns
- Skin tears
- Friable or delicate skin
Primary wound contact layers
The properties of dressings such as Silflex® include:
- Adheres only to dry skin not to a moist wound
- Atraumatic soft silicone; reduced pain on dressing change
- Allows passage of exudate
- Soft and conformable
- For use with absorbent secondary dressings
They are recommended for:
- Skin tears
- Skin abrasions
- Surgical wounds
- Second degree thermal burns
- Lacerations
- Leg ulcers
- Pressure sores
- Negative pressure wound therapy
Primary dressing silicone sheets
The properties of primary dressing silicone sheets such as Molnlycke Mepiform®, Advasil® conform include:
- Minimal pain and trauma at dressing changes
- No extra fixation is needed
- Thin, flexible and discreet
- Can be worn in daily activities
- Can be reapplied
- Can be cut to size
- Waterproof
They are used for:
- Hypertrophic and keloid scars (old and new)
- Closed wounds – as prophylaxis against hypertrophic or keloid scar development
Silicone gel
Silicone gels such as Silderm®, Kelocote® are:
- Easy to use
- No requirement for adhesive dressings
They are also used for:
- Hypertrophic and keloid scars (old and new)
- Closed wounds – as prophylaxis against hypertrophic or keloid scar development
Silicone tape
Silicone tape includes Siltape®, 3M Kind® removal.
- Atraumatic soft silicone
- Reduced pain on change, adjustment, or removal
- Soft and conformable
- Adheres only to dry skin not to a moist wound
- Easily adjustable with no loss of adherence
It is used to:
- Hold dressings in place
- Tape down eyelids (in theatre)
- Secure IV lines
- Over small incision sites
- Protect from pressure damage or sores from tubing
*For specific details of recommendations for use, consult the manufacturer’s product information.