Assertion: whitening's result | /r/Causes | stain
Facets:
value: in some cases
type: TEMPORAL
value: on tooth enamel
type: LOCATION
Source sentences:
text: While strips and lights and in-office procedures have all been touted as the next big thing in tooth-whitening, their results aren't always consistent, and, in some cases, can even cause stains on tooth enamel.