An N95 mask does not have to dam all particles, so even if there is a poor seal, any air flowing by way of the filter means cleaner respiratory for you.
Surgical and N95 Masks are personal protecting equipment used to guard the mouth and nostril from contact with doubtlessly contaminated airborne particles.
An N95 respirator is a respiratory protecting system designed to realize a very shut facial fit and very environment friendly filtration of airborne particles.