I learned that tetracycline can cause tooth discoloratoin when taken orally. How about topical use as a creme? Can tetracycline also stain the tooth through skin absorption?
Tetracycline topical is generally well tolerated. Side effects reported with systemic administered tetracycline such as gastrointestinal complaints, vaginitis, hematologic abnormalities, dental, and skeletal disorders have not been reported and are unlikely to occur with topical administration.
A faint yellowing of the skin has been reported, especially around the hair roots
This link agrees with the above.
When taken orally tetracycline can cause discolouration in developing teeth and should be avoided - when possible - in young children. Systemic tetracycline will have no effects on the colour of fully erupted teeth. So not something an adult needs to worry about !
"Discolouration of the teeth occurs in a high proportion of children undergoing antibiotic therapy with drugs of the tetracycline group during the time of tooth development."
Oral Diagnosis 2nd Edition W R Tyldesley page 69