Rotary Technical Considerations

 

PROPER USE:

These instruments have been designed for their specific uses and are to be used by dentists and other qualified dental professionals who are familiar with the safe handling of these rotary tools. Improper use can cause harm to the instruments and handpieces, but more importantly, hazard to the patient and user.

  • The instruments must be inserted into the handpiece chuck as far as possible.
  • The shafts of the burs must be secured properly into the handpiece.
  • Ensure that the instrument and handpiece are operating at the proper working speed before applying to the material surface.
  • Always use the proper operating speeds and working pressures when using rotary instruments.

RECOMMENDED SPEEDS:

  • Please observe the recommended speeds for the instruments.
  • When using instruments that have a larger working area than that of the diameter of their shank, increased centrifugal forces may occur when the speed is too high. This can lead to bending of the shank and/or breakage of the instrument. For this reason, the maximum permissible speed must not be exceeded.
  • Please note – the larger the working part, the slower the speed.

WORKING FORCE & COOLING:

  • Excessive contact pressure must always be avoided. With cutting tools, the application of added force and pressure by the operator does not result in faster material removal material, but tends to damage the working surfaces of the instruments, causing blade fracture, head separation and the dislodging of abrasive grit. Too much working pressure can also cause added heat generation that leads to irreversible tissue and dental pulp injury.
  • To avoid high heat generation, sufficient use of irrigation (at least 50 mL/min) must be provided.

DISINFECTION, CLEANING & STORAGE:

  • All instruments are packaged in a non-sterile condition and must be sterilized prior to use. Sterilization has to be carried out according to appropriate, validated procedures.
  • Prior to the first use on the patient and immediately after each use, all rotary instruments have to be disinfected, cleaned and material-compatible sterilized.

STEPS TO PROPERLY CLEAN AND STERILIZE CARBIDE & DIAMOND INSTRUMENTS:

CLEANING:

  1. Wear gloves when handling contaminated instruments. To loosen debris, pre-soak instruments in a container of soapy water. Ultrasonic cleaning is highly effective, but it is recommended that cutting instruments be separated from one another in a bur block during immersion to prevent damage to the cutting surfaces.
  2. Brush away remaining debris and rinse burs under running water.
  3. After rinsing, dry burs thoroughly.

STERILIZATION:

(Always refer to the user manual of your specific sterilization equipment for specific protocols)

  1. Dry Heat Sterilizers 170°C (340°F) for 1 hour. This method, when used according to manufacturer instructions, will reduce corrosion and will lessen the dulling effects on carbide burs.
  2. Steam autoclaves 121°C (250°F) for 20 minutes @ 15 p.s.i. Steam autoclaves will effectively sterilize carbide and diamond cutting tools; however, potential for corrosion is present.

Cold Sterilization solutions should be avoided as they often contain oxidizing agents and glutaraldehyde that may weaken carbide burs and can attack the matrix that adheres the diamond particles to steel blanks.

WORN INSTRUMENTS:

Pay close attention to the performance of your rotary tools for excessive wear, dulling and damage to the cutting surface. Damaged instruments that are beyond their service life and instruments that exhibit bent or non-concentric properties need to be immediately discarded. Further use of such worn, damaged or deficient instruments can lead to the operator applying more pressure resulting in excessive heat and possible breakage of the instrument.