Zipper
a screw is a fastening device
Allen Key or Hex Key
nails
A homonym for "zip" is "zip," as it can mean a buzzing sound, a fastening device, or to move quickly.
The name of the fastening device made from round or oval wire is a "staple." Staples are commonly used to join or bind materials together by driving them into the material with a stapler or similar tool.
Screws, bolts, etc. with a hexagonal hole are known as "hex" or "Allen". Said fastening devices are driven into (or out of) substrate with a "hex key" or "Allen key" set.
A zip, short for zipper, is a fastening device used in textiles to open and close garments or accessories. Zips typically consist of two strips of fabric with interlocking teeth that slide together to secure the opening. They are commonly used in clothing, bags, and other textile products.
Zippers are typically made out of metal, plastic, or coil teeth attached to a fabric tape. The teeth interlock to close the zipper and create a secure fastening mechanism for clothing, bags, and other items.
Because, without teeth, your mouth would have no other device to chew with.
Bristles or a screening device
Cameras are an electronic device that takes pictures and videos. Therefore a camera is incapable of brushing its teeth because it has no teeth like people do.
retainer