Disposable gowns: weight is not a measure of protection, and it is the commonest purchasing error

The disposable gown is almost always bought by looking at two numbers: the price and the weight. The second is read as an index of quality, and it is the commonest error in this category.

Weight, expressed in grams per square metre, indicates how much the nonwoven fabric weighs. It says something about mechanical robustness — a 20-gram gown tears more easily than a 40-gram one — but nothing about the capacity to stop fluids.

Protection depends on the structure of the material, not on its weight. Plain spunbond, however heavy, lets fluids through because the fibres form a mesh with open spaces. SMS, alternating spunbond and meltblown layers, stops fluids even at lower weights.

The meltblown layer does the work: far finer fibres forming a physical barrier to fluids while maintaining air passage. It is the same principle as surgical masks, where protection lies in the inner layer and not in overall thickness.

The European reference standard classifies gowns by performance against fluid penetration, and the class is stated on the packaging. A gown without a stated class is a work coat, not protective equipment, however robust it appears.

For most dental procedures a barrier against splashes and aerosol is required, not against immersion. A 35-gram SMS with elasticated cuffs covers nearly all daily requirements.

Procedures with heavy bleeding — complex extractions, implant surgery, sinus lift — require a gown with impermeable reinforcement on chest and sleeves, where contamination is most likely.

The reinforcement is typically a laminated polyethylene layer applied only to critical zones. It makes sense precisely because it is localised: a fully impermeable gown becomes unbearable after twenty minutes, and an overheated operator is a distracted operator.

Breathability is not comfort but performance. Perspiration under an occlusive gown reduces precision in long procedures and prompts touching the face — which is exactly the gesture the gown should render unnecessary.

Cuffs deserve attention because they are the point where the barrier is interrupted. The elasticated knit cuff must go under the glove, not over it: the correct overlap is glove over cuff, otherwise fluid runs along the forearm.

Rear closure is preferable to front closure in surgical procedures, because the front remains intact. In restorative sessions a front-closing gown is acceptable and quicker to put on.

A practical detail affecting consumption: the disposable gown is single-use per patient, not per day. Reusing it between patients defeats the reason it exists, and the temptation grows when the gown still looks clean — but aerosol contamination is not visible.

In summary, a gown is chosen by reading the protection class and the material type, not the weight. A 35-gram SMS with a stated class protects better than a 50-gram spunbond without one, and costs less.