Effect of the topical application of 50% lignocaine hydrochloride on the sensitivity of dentine in man

Lignocaine will diffuse into exposed dentine and block the pain evoked by probing and air-blast stimuli provided that a sufficiently steep diffusion gradient is created. A topical application of a 50% (w/v) solution of lignocaine HCl for 10 min will anaesthetise dentine within 30 min.