Abrasive And Polishing Units In Dentistry

Abrasive And Polishing Units In Dentistry

Write a short note on abrasive and polishing units.
Answer:

Following are the Abrasive and Polishing Units:

• Finishing burs: Burs are made of stainless steel or tungsten carbide. 12–40 fluted carbide burs are usually recommended for finishing depending upon the restorative material. Plain burs are also used before final polishing.
• Diamond instruments and pastes: It is considered a super abrasive because it is the hardest material known and is capable of abrading almost any other material. It is available commercially in the form of bonded abrasive rotary instruments, metal-backed abrasive strips, and polishing pastes.
• Finishing diamonds of medium-fie grit contain diamond particles of 840 µm in diameter. They should always be used with a light force and copious water spray to preserve the very fie diamond coatings. Diamond polishing pastes are also available with particle sizes ranging from 2–5 µm. Diamond abrasives are preferably used on ceramic and composite materials.
• Brushes: Brushes can be used either alone or in combination with abrasive particles. Most of the brushes have synthetic bristles, others may have wire bristles for polishing cast restorations.
• Cloth: Cloth carried on a metal wheel may be used for final polishing with/without a polishing medium.
• Felt: Felt is used to attain luster for the metallic restorations usually with a polishing agent. It is available in different shapes of wheels, cones, and cylinders.
• Rotary rubber instruments:
  • Rubber-ended rotary tools are commonly used for polishing procedures.
  • They can be obtained in various shapes of cups, wheels, cones, etc., and are commonly used with other abrasives or polishing pastes.
• Coated discs and strips:
  • The abrasive particles such as sand, cute, garnet, boron carbide, silicon carbide, etc. are held onto a flexible heavy-weight paper or mylar strips with a suitable adhesive material.
  • The discs may be attached to a mandrel for rotary finishing. Abrasive strips are used by hand in a back-and-forth motion, especially for finishing proximal areas.