intrinsic staining

in·trin·sic stain·ing

(in-trinzik stāning)
Discoloration of internal tooth structure due to factors derived from within the body; an effect of substances such as the antibiotic tetracycline. Such stains are not usually removable but may be treated through cosmetic dental procedures.
References in periodicals archive ?
The intra-oral examination when the child reported at 17 months showed green intrinsic staining of all the erupted primary teeth (chlorodontia).
Harder/deeper extrinsic discoloration and intrinsic staining require various bleaching techniques.
Conditions which cause intrinsic staining of teeth are: