can be either extrinsic or intrinsic. extrinsic stain is located on the outside of the tooth surface originating from external substances such as tobacco, coffee, tea or food; usually removed by polishing the teeth with an abrasive prophylaxis paste. Intrinsic stain originates from the ingestion of certain materials or chemical substances during tooth development, or from the presence of caries. This stain is permanent and cannot be removed.