Amino-acid Composition of the Acquired Pellicle of Human Tooth Enamel

AFTER eruption human teeth acquire a structureless film, tenaciously attached to the enamel surface, which may be liberated from clean, debris-free, healthy teeth by immersion in a solution of strong mineral acid. This acid-insoluble cuticular structure has been given various names by different authorities, and in a review of the confused nomenclature on this subject it was recommended that the term ‘acquired pellicle’ be used 1 . Various possible origins for this pellicle layer have been proposed, and while it has usually been assumed that it is most probably of salivary origin it has also been considered that it may be ( a ) a horny keratinous layer formed from oral epithelium 2 ; ( b ) the remains of a collagenous cementum-like layer over the occlusal surface of the teeth 3 ; ( c ) dental plaque which had become structureless due to lysis of its bacteria 4 . A recent suggestion is that it may be derived from denatured haemoglobin 5 .