Ultrasonic scalers

• What is an ultrasonic scaler?

  A power-driven scaling instrument
• What frequency range does an ultrasonic scaler operate in?

  25,000 to 50,000 cycles per second
• How does an ultrasonic scaler convert electrical energy?

  Into mechanical vibrations
• What are the three modes of action of ultrasonic scalers?

  Mechanical vibration, cavitation, irrigation
• What happens during mechanical vibration in ultrasonic scalers?

  Electrical energy converts to high-frequency sound waves
• What effect do sound waves have in ultrasonic scalers?

  They produce rapid vibrations in the scaling tip
• What is the result of vibrations applied to deposits on teeth?

  Deposits are shattered from the tooth surface
• Why is water essential in the cavitation process?

  To dissipate heat produced from the vibrating tip
• What occurs when water meets the vibrating tip?

  Minute bubbles are created that collapse
• What is the purpose of cavitation in ultrasonic scaling?

  To destroy surface bacteria and remove endotoxin
• How does irrigation assist during ultrasonic scaling?

  It flushes endotoxins and loose debris out
• What chemical solution was previously used for irrigation?

  Chlorhexidine
• What is amplitude in the context of ultrasonic scalers?

  Distance of tip movement
• What is frequency in the context of ultrasonic scalers?

  Speed of movement
• What are the two types of powered scalers at UPDA?

  Magnetostrictive and piezo-electric scalers
• How does a magnetostrictive scaler work?

  It produces a magnetic field causing vibration
• What is the frequency range of magnetostrictive scalers?

  18,000 to 45,000 cycles per second
• What pattern does the metal tip of a magnetostrictive scaler move in?

  Elliptical pattern
• How many surfaces of the insert tip are active in magnetostrictive scalers?

  All surfaces/sides of the insert tip
• How does a piezo-electric scaler operate?

  Electric current causes dimensional change in crystals
• What is the frequency range of piezo-electric scalers?

  25,000 to 50,000 cycles per second
• What type of movement does the tip of a piezo-electric scaler have?

  Linear movement
• How many sides of the insert/tip are active in piezo-electric scalers?

  Two sides of the insert/tip
• What are nodal points in ultrasonic scalers?

  Areas that do not create any vibration
• Why is it important to check the length of the tip using a wear guide?

  Shorter tips reduce movement near nodal points
• What are some general contraindications for using ultrasonic scalers?

  Infectious diseases, immunosuppression, respiratory problems
• What oral condition contraindicates the use of ultrasonic scalers?

  Demineralisation
• What is another oral condition that contraindicates ultrasonic scalers?

  Exposed dentine
• What precautions should be taken with certain materials during ultrasonic scaling?

  Amalgam, porcelain, composite, titanium implants
• What is the purpose of using ultrasonic units in a phantom head?

  To rotate stations and experience both types
• What should be done with ultrasonic units after use in a phantom head?

  Leave them as found at the start
• What are the key components of ultrasonic scalers' operation?

  • Mechanical vibration
  • Cavitation
  • Irrigation
• What are the differences between magnetostrictive and piezo-electric scalers?

  Magnetostrictive:

  • 18,000 to 45,000 cycles per second
  • Elliptical tip movement
  • All surfaces active

  
  

  Piezo-electric:

  • 25,000 to 50,000 cycles per second
  • Linear tip movement
  • Two sides active
• What are the contraindications for using ultrasonic scalers?

  General contraindications:

  • Infectious diseases
  • Immunosuppression
  • Respiratory problems

  
  

  Oral conditions:

  • Demineralisation
  • Exposed dentine
• What precautions should be taken with materials during ultrasonic scaling?

  • Amalgam
  • Porcelain
  • Composite
  • Titanium Implant Abutments
• What does "supra-gingival" mean?

  "Above" the gingiva
• What is calculus in dentistry?

  An adherent calcified substance on teeth
• What is the composition of calculus?

  • 20-30% Organic:
  • Plaque matrix
  • Protein & Carbohydrate
  • Desquamated epithelial cells
  • Leucocytes
  • Food debris
  • Micro-organisms
  • 70-80% Inorganic:
  • Mainly Calcium Phosphate
  • 2/3 in crystalline form
• Why do we remove calculus?

  It encourages plaque formation
• What is the role of dental professionals regarding calculus?

  To enable patients to maintain plaque control