Indentured servants or bonded laborers
An indentured servant, or the U.S. bonded laborer, is a laborer under contract to work for an employer for a specific amount of time, to pay off a passage to a new country or home
Typically the employers provided little if any monetary pay, but they were responsible for accommodations, food, other essentials, and training. Upon completion of the term of the contract the laborer sometimes received a lump sum payment; such as, a parcel of land and was free to farm or take up a trade of his own.
Indentured servants, were furnished passage to various British colonies (not just America) on the condition that they work upon arrival for their sponsor, were so-called because they were bound by a document called an "indenture", a legal contract spelling out the terms of their agreement.
"Indentures" originally had a metaphorical relation to teeth. One of the earliest methods of ensuring the authenticity of a legal document or contract was to make two or more copies, sign them, place them in a stack, and tear or cut all the copies along a jagged or notched line.
Any later challenge to the legality of one copy could then be resolved by matching the jagged edge to that on another of the copies. Given that such jagged or notched tears resembled teeth, the term "indenture" (from the Latin indentare, meaning "to furnish with teeth") has been in use since the 14th century.
The term comes from the medieval English "indenture of retainer" which was a contract written in duplicate on the same sheet, with the copies separated by cutting along a jagged ("toothed", hence the term indenture) line so that the "teeth" of the two parts could later be refitted to confirm authenticity.
Some "indentured labor" has been classified as a form of slavery; for example, there were situations where indentured servants were forced to purchase goods or services from the employer in exchange for an extension to the period of their indenture.
To put a "dent" in something is not related to the "tooth" dent
It should be noted that our modern indent, or to make a dent comes from a different origin. The familiar verb "dent" is rooted in the older term dint meaning "to make an impression in something"; and is completely unrelated to the dent of the "teeth" family.
From about the year 1325, "a strike" or "a blow", a dialectal variant of Middle English dint.