Ultrasonics Magnetostrictive

Question 1

Why do we use ultrasonic scalers?

Answer 1

The goals of periodontal debridement are to:

1. Arrest infection and maintain a healthy periodontium by eliminating the pathogenic microorganisms on the tooth and root surface
2. Remove hardened calculus deposits and dental plaque biofilm from the sulcus or pocket
3. Produce a biologically acceptable tooth/root surface

Question 2

Describe the fundamental differences between a Magnetostrictive, Piezoelectric and Sonic Scaler in terms of:

• Optimal freqeuncy
• Transducer (what converts energy to vibration)
• Stroke pattern
• Power dispersion to tip

Answer 2

Magnetostrictive:
Optimal frequency
* 20- 42 kHz

Transducer (what converts energy to vibration)
* Nickel alloy wafers or solid rod

Stroke pattern
* Elliptical

Power dispersion to tip
* All surfaces active

Piezoelectric:
Optimal frequency
* 29- 32 kHz

Transducer (what converts energy to vibration)
* Ceramic

Stroke pattern
* Linear

Power dispersion to tip
* Lateral surfaces more active

Sonic Scaler:
Optimal frequency
* 2500 - 7000 cycles per second

Transducer (what converts energy to vibration)
* Driven by compressed air

Stroke pattern
* Elliptical or orbital

Power dispersion to tip
* All surfaces active

Question 3

Describe the characteristics of the Magnetostrictive ultrasonic, including tip motion, cavitation, acoustic streaming and irrigation

Answer 3

• Tip motion: The tip oscillates at ultrasonic frequencies (25kHz, 30kHz or sometimes slightly higher). The tip vibrates in an elliptical path.
• Cavitation: The ultrasonic oscillation of the tip also causes cavitation of the water coolant. Cavitation is the production of microscopic bubbles which implode, releasing energy. This helps disrupt the calculus on the surface of the tooth and has also been thought to have an antibacterial action

Question 4

Describe pre-use assessment for ultrasonic use

• Clinical data
• Pre use assessment

Answer 4

Start with clinical data:
• Use clinical data to determine best possible instruments to achieve optimal clinical outcomes
• Periodontal chart and current radiographs 
• Deposit characteristics 
• Heavy or light 
• Anatomical features 
• Pocket topography 
• Root morphology 
• Instrument access

Pre-use assessment:
• Patient: Significant supra-/ sub-gingival calculus is evident. Be aware of contraindications and other considerations
• Explain procedure to patient
• PPE for you and patient
• Water control available: Slow speed suction and High volume suction (HVE)

Question 5

Understand and discuss the contraindications for use

• Systemic issues
• Teeth related

Answer 5

Systemic issues
• Patients with a predisposition to infection (i.e. after organ transplants, etc.)
• Patients with infectious diseases transmitted by aerosols (i.e. Tuberculosis, Strep Throat, patients suffering from severe Cold/Flu Virus etc.)
• Patients with Respiratory/Pulmonary diseases (i.e. severe Asthma, Emphysema, Cystic fibrous etc.)
• Patients with an Unshielded pacemaker (magnetostrictive)
• Women who are pregnant 1st trimester ??? (evidence currently unclear)

Teeth related
• Areas of demineralisation or occlusal surfaces
• Areas of recession or sensitivity
• On restorations (i.e. porcelain veneers, margin of gold/porcelain crowns, etc.)
• Around titanium implants without a plastic/teflon coated tip
• Children: primary/newly erupted permanent teeth
• Occlusal surfaces

Question 6

List the Advantages and Disadvantages of Magnetostrictive use

Answer 6

Advantages
• Less time consuming
• Lavage (flow of water) improves vision
• Easier access for furcations 
• Less physical stress for the hand/oral health therapist

Disadvantages
• Reduced tactile sensitivity 
• Production of contaminated aerosol
• Potential to damage root surfaces if not used properly
• Producing rough root surfaces

Question 7

Identify the types of tips available

Answer 7

Round

Diamond shape

After Five - Right and Left Inserts

Question 8

Describe the uses of round, diamond shaped and after five tips

Answer 8

Round: straight shank can be used on all accessible tooth surfaces

After Five® Inserts (Straight, Left and Right): Probe-sized inserts used to remove light deposits in periodontal pockets with improved adaptation in interproximal areas

Diamond shaped:
• Beveled edge design
• Unique pattern of bends increases access interproximally and around line angles

Question 9

Identify the appropriateness of power level selection

Answer 9

Power
• Ultrasonic systems convert electrical energy into mechanical vibration of the instrument tip

• Frequency (speed): The number of times the tip travels back and forth per second. Measured in cycles per second (CPS) or (Hz)
• Amplitude (distance): the distance the tip travels with each stroke
• Frequency + Amplitude = power
• Increasing power on ultrasonic scalers = increased stroke length and tip vibration

Question 10

Describe the proper use and set up and technique of the magnetostrictive ultrasonic scaler

Answer 10

• Place the power driven instrument on a stable countertop
• Fill handpiece with water to expel air bubbles and prevent the hand piece from overheating
• Grasp the insert grip and gently twist the insert into the handpiece until it snaps into place
• Set Power and Water volume: Medium to Low power, depending on type of deposit being removed. Slow to medium water

• Using too little water with a warm hand piece a warning sign of inadequate water

Question 11

What are the types of strokes available subgingivally?

Answer 11

Steps: The deepest part of the pocket of the respective site is detected using vertical strokes
• The tip is then moved slowly towards the sulcus using horizontal/oblique strokes

• Vertical detection strokes are used again to detect the neighbouring bottom of the pocket
• The neighbouring 2-3mm is cleaned using horizontal or oblique strokes, slightly overlapping the former 2-3mm

Question 12

Discuss the correct tip placement of an Magnetostrictive ultrasonic scaler

Answer 12

• Face of Magnetoconstictive powered instrument tip should not be directly adapted to tooth surface
• The Point can be used with caution but only to “tap” directly onto large calculus deposits to help break them from the tooth surface, NEVER on tooth surfaces directly
• The last 2-4mm of the lateral surfaces are the active portion of the tip and must be in contact with the tooth at all times
• The tip-to-tooth surface angulation should be close to zero degrees (parallel)

Question 13

Discuss the difference between an effective and ineffective scaling tip due to wear

Answer 13

• Scaling efficiency is significantly diminished with worn insert tips, requiring greater effort and time to achieve desired results
• 2mm of wear = time to replace the tip
• For optimal scaling efficiency, check tips regularly for signs of wear using the Tip Wear Guides provided by all manufacturers