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Chapter 35

Chapter 35. Dental Handpieces and Accessories. Dental Handpieces and Accessories. Pronounce, define, and spell the Key Terms. Discuss the historical importance of the dental handpiece. Discuss dental handpieces, including: Describe the low-speed handpiece and its uses in dentistry.

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Chapter 35

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  1. Chapter 35 Dental Handpieces and Accessories

  2. Dental Handpieces and Accessories Pronounce, define, and spell the Key Terms. Discuss the historical importance of the dental handpiece. Discuss dental handpieces, including: Describe the low-speed handpiece and its uses in dentistry. Describe the attachments used with the low-speed handpiece. Describe the high-speed handpiece and its uses in dentistry. Review other handpieces used in dentistry. Discuss handpiece maintenance. Lesson 35.1

  3. Dental Handpieces and Accessories Describe rotary instruments and how they are used. Do the following regarding burs: List the parts of a bur. Describe the composition, shape, and uses of diamond burs. Explain the difference between a finishing bur and a cutting bur. List the types of abrasive rotary instruments. Explain the difference between laboratory burs and dental burs. Lesson 35.1

  4. Introduction • When attached to a specific handpiece, rotary instruments operate at different speeds to accomplish different functions in the cutting, polishing, and finishing of tooth structure in the restoration process

  5. Evolution of Rotary Equipment • 1940s • Introduction of rotary instruments • Belt-driven handpiece • Development of diamond cutting burs • 1950s • Invention of tungsten carbide • Development of the air-driven turbine handpiece

  6. Dental Handpieces • The dental handpiece is the most frequently used instrument in restorative dentistry • It provides power to a rotary instrument that is used to complete the actual cutting or polishing of tooth structure and castings

  7. Low-Speed Handpiece • Designed two sizes: standard length and “shorty” • Speeds range from 10,000 to 30,000 rotations per minute (rpm) • The rotary instrument (bur) can be positioned to operate in both a forward and a backward movement

  8. Low-Speed Handpiece (Cont.) From Robinson D, Bird D: Essentials of dental assisting, ed 5, St Louis, 2013, Saunders.

  9. Uses of the Low-Speed Handpiece • Clinical • Removal of soft decay and fine finishing of a cavity preparation • Finishing and polishing of restorations • Coronal polishing and removal of stains • Porcelain adjustments • Root canal treatment • Laboratory • Trimming and contouring of temporary crowns • Trimming and relining of removable partials and dentures • Trimming and contouring of orthodontic appliances

  10. Straight Attachment • Slides onto the low-speed motor and locks into place • Most commonly used for • Laboratory procedures • To trim provisionals and additional acrylic prostheses made outside of the mouth

  11. Contra-Angle Attachment • Slides onto the low-speed motor and locks into place • The angle of the attachment is designed to allow the operator intraoral access with easier adaptation to tooth surfaces • This attachment holds: • Latch-type rotary instruments • Latch-type endodontic files • Latch-type prophy cups • Latch-type mandrels

  12. Prophylaxis Angle • Used during polishing procedures to hold the prophylaxis cup and bristle brush • Two types • Plastic disposable “prophy” angle • Metal “prophy” angle

  13. Disposable Prophy Cup and Brush

  14. High-Speed Handpiece • Design • One-piece unit with a slight curve • Operated by air pressure • Operates at speeds as high as 450,000 rpm • Maintains a water-coolant system • Friction-grip locking system for rotary instruments • Fiberoptic lighting

  15. High-Speed Handpiece (Cont.) From Boyd LRB: Dental instruments: a pocket guide, ed 5, St Louis, 2015, Saunders.

  16. Uses of the High-Speed Handpiece • Removal of decay • Removal of an old or faulty restoration • Reduction of the crown portion of a tooth in preparation for a crown or bridge • Preparation of an outline and retention grooves for a new restoration • Finishing or polishing of a restoration • Sectioning of a tooth during surgery

  17. Water Coolant System • The extreme high speed of the bur or stone attached to the high-speed handpiece can generate frictional heat on a tooth, possibly causing damage to the pulp • The high-speed handpiece is designed to handle a water coolant system • The tooth and bur are constantly sprayed with cool water while operating • The water spray also helps remove debris from the tooth preparation and allows the operator better visibility

  18. Bur Adaptation • Burs for high-speed handpieces have a different locking system than those for low-speed handpieces • High-speed handpieces operate with a friction-grip device • Some older handpieces require the use of a bur-changing device • For others with a release built into the head of the handpiece, a bur-changing device is not required

  19. Fiber Optic Lighting • High-speed handpieces are equipped with a fiber optic light that is mounted in the head of the handpiece • Light ports near the bur deliver the proper amount of light directly onto the operating site

  20. Ultrasonic Handpiece • Design • Attaches to the dental unit for water, or has its own self-contained water or medicament supply • Powered by electricity • Used for scaling and root planing and prophylaxis appointments • Attachments similar in appearance to scaling instruments • Delivers a pulsating spray of water

  21. Ultrasonic Handpiece (Cont.) Courtesy Dentsply Professional Division, York, PA.

  22. Laser Handpiece • Uses a beam of laser light to cauterize soft tissue or vaporize decayed tooth structure • Resemblance to a standard handpiece • Water and air to cool the tooth and keep the area clean • Benefits include painlessness and not having to wait for anesthesia to work

  23. Precautions of Laser Handpieces • Do not sharply bend or twist the fiber optic cable • Do not touch the exposed fiber optic cable • Do not touch the end of the fiber optic cable connector • Keep the connecting parts clean

  24. Air Abrasion Handpiece • Small version of a sandblaster • Designed to remove stains and tooth decay • High-pressure delivery of aluminum oxide particles through a small probe • Removes enamel, dentin, and restorative materials without compromising healthy tooth structure

  25. Uses of the Air Abrasion Handpiece • Preparation of teeth for sealants • Removal of external stains • Class I through class VI preparations • Endodontic access • Crown margins • Preparation of the tooth surface for the cementation of a cast restoration (e.g., a crown or veneer)

  26. Laboratory Handpiece • Operates at speeds as high as 20,000 rpm • Uses laboratory burs • Greater torque than that of handpieces used intraorally

  27. Handpiece Maintenance • General considerations • Wear personal protective equipment and follow universal precautions • Clean debris from the external surface • Clean the internal components of the handpiece • Handpiece must be dry before being packaged • Wrap the handpiece for sterilization • Sterilize the handpiece • Wipe the light port on the fiber optic with an alcohol swab to remove any excess lubricant

  28. Sterilization Procedure Sheets • Sterilization instructions vary not only between manufacturers but also between different models made by the same manufacturer • Use of a sterilization procedure sheet is one way to avoid errors in handpiece sterilization

  29. Rotary Cutting Instruments • Three basic parts to a rotary instrument • Shank: Portion that fits into the handpiece • Straight shank • Latch-type shank • Friction-grip shank • Neck: Portion of the rotary instrument that connects the shank and the head • Head: The cutting, polishing, or finishing portion

  30. Bur Parts and Types of Shanks From Robinson D, Bird D: Essentials of dental assisting, ed 5, St Louis, 2013, Saunders.

  31. Dental Burs • All rotary instruments with sharp cutting head • Uses: • Preparing the tooth • Excavating the decay • Finishing cavity walls • Finishing restoration surfaces • Removing old fillings • Finishing crown preparations • Separating crowns and bridges • Adjusting and correcting acrylic temporary crowns

  32. Bur Shapes • When discussing the “shape” of a bur, you are referring to the contour or design of the head of the bur • Burs are manufactured in a variety of shapes, and each shape is available in a variety of sizes • A bur will have a name, a series of numbers attached to its shape, and a purpose for use

  33. Diamond Rotary Instruments • Diamond burs are often used for crown preparations • Diamond burs have a metal base, with flecks of industrial diamonds embedded into the base • The most frequently selected diamond burs include: • Round: Provide access to pulp chamber • Flat end taper: Reduce tooth structure during a crown preparation • Flame: Reduce tooth structure in preparation for a crown • Wheel: Make subgingival bevels in a crown preparation

  34. Finishing Rotary Instruments • A finishing bur is similar in appearance to the cutting bur, except the number of blades, or flutes, in the working end of the finishing bur is increased • The greater the number of cutting surfaces on the head of a bur, the greater is its polishing or finishing capability • Tapered, round, or flame-shaped

  35. Finishing Burs Courtesy Miltex Inc., York, PA.

  36. Abrasive Rotary Instruments • The most varied of the rotary instruments • Many types of abrasive material are applied to many shapes to create a flexible working surface that can be adapted to the contour of a tooth or restoration • Abrasive materials are made in shapes ranging from disks and stones to points and strips

  37. Accessory Attachments for Rotary Instruments B from Boyd L: Dental instruments: a pocket guide, ed 5, St Louis, 2015, Saunders.

  38. Accessory Attachments for Rotary Instruments (Cont.) D from Boyd L: Dental instruments: a pocket guide, ed 5, St Louis, 2015, Saunders.

  39. Accessories • Abrasive disks and wheels are supplied separately and are not attached to a shank • A mandrel is used to attach these abrasives to the dental handpiece • Mandrels are designed according to the different types of shank so that they may be used in both low-speed and high-speed handpieces

  40. Laboratory Rotary Instruments • Laboratory burs have a longer shank and a larger head than dental burs • Laboratory burs are used in the low-speed handpiece for functions such as cutting and polishing of acrylic • The acrylic bur is the bur that is most commonly used in the laboratory

  41. Varying Shapes of Laboratory Acrylic Burs Courtesy Integra LifeSciences Cor­poration, Plainsboro, NJ.

  42. Questions?

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