Power-Driven Scalers in Periodontal Treatment

• Power Driven Scalers use magnetostrictive.
• Foundations of Clinical Skills and Practice

GDC Learning Outcomes

• 1.1.1
• 1.1.5
• 1.5.3
• 1.8.1
• 1.11.3
• 8.2
• 9.6
• 10.8

Intended Learning Outcomes

• Explain the rationale for using a Power Driven Scaler (PDS) as a part of periodontal treatment.
• Explain the modes of action of a PDS
• Discuss the advantages and disadvantages of PDS
• Explain the difference on frequency and amplitude in PDS and their impact on delivery of care
• Explain the anatomy of the PDS tip and impact of clinical adaptation
• Explain the key differences between sonic, piezo and magnetostrictive scalers
• Discuss key safety checks to be undertaken prior to and during PDS use

History

• Manual instrumentation/debridement was the only method available for the safe removal of supra and sub gingival calculus until ultrasonic devices were introduced around 1950.

Power Driven Scalers

• An umbrella term for al power driven scalers, routinely seen is general practice
• Piezoelectric
• Magnetostrictive
• Sonic

What is a Power Driven Scaler?

• A power driven scaler accomplishes the task of removing plaque and calculus from the tooth surface by means of a mechanical action.
• Power driven scalers convert high frequency electrical energy (ultrasonic) or air pressure (sonic) into high frequency sound waves.
• The energy at the tips fracture calculus from the tooth surface
• Assists in cleansing pathogens from within the periodontal pocket

Why Use a Power Driven Scaler?

• Optimal treatment outcomes
• Better access to complex areas
• Disturbance of plaque biofilm
• Reduce operator fatigue
• Make optimum use of appointment time
• Reduced patient discomfort

Modes of Action of PDS

• Cavitation effect
• Acoustic turbulence
• Lavage
• Mechanical

Cavitational Affect

• Cavitation is the formation of pulsating bubbles that are powered by an ultrasonic field.
• When an ultrasound wave passes through water, molecules are pushed closer together and pulled apart in a split second.
• Micromillimeter-sized bubbles expand and collapse violently when movement of these sound waves is high.
• The subsequent energy is released as a shock wave, heat, and/or abrupt changes in nearby hydraulic pressures.
• Within the coolant, thousands if not millions, of other bubbles are produced that will then collapse, creating the appearance of pulsation.

Acoustic Micro Streaming

• Acoustic micro streaming is another energy released around ultrasonic devices.
• This phenomenon is characterized by the movement of small currents in the water.
• Micro streaming commonly occurs around oscillating objects, such as cavitation bubbles or the scaler tip.
• Currents produce shear forces strong enough to break up clumps of bacteria but not powerful enough to break down bacterial cell walls.
• These forces break up colonies of bacteria and disrupt biofilm.

Advantages of Power Driven Scalers

• Easier removal of heavy deposits/stain
• Reduction of tissue trauma
• Lavage
• Cavitational effect
• Acoustic disturbances
• Furcation tip access causes less damage
• Less tissue distension
• Conservation of cementum
• Time management
• No sharpening needed
• Reduces operator fatigue and likelihood of carpel tunnel syndrome/repetitive strain
• Patient prefers it

Disadvantages of Power Driven Scalers

• Reduced visibility due to water accumulation
• Patients who cannot breath through their nose
• Tooth sensitivity during procedure
• Reduced tactile sense
• Mirror use limited due to water spray
• Aerosol formation
• Noise
• Compromised procedure without nursing assistance
• Running out of water in the bottle
• Patients wearing hearing aids may have to remove them
• Patient dislikes it

Clinician considerations of PDS use

• Oral Control
• Contraindications of use
• How it works
• Adaptation - Tip anatomy
• Recognising a failing tip
• Maintenance

Contraindications to Use

• Pacemaker *
• High susceptibility to infections
• Respiratory risk
• Difficulty in swallowing
• Prone to gagging
• Sensitivity
• Untreated cleft palate
• Areas of demineralisation
• Around crowns/implants? *

Frequency

• Frequency relates to the power
• Described as Low Power (Blue Zone), Med. Power, and High Power

Frequency

• Ultrasonic powered devices operate at 18,000 to 45,000 cycles per second
• Sonic powered devices operate at a lower frequency of 3,000 to 8,000 cycles per second

Tip Anatomy

• Active tip area

• Points of energy dispersion at Point, Back, Face, Lateral Surface

• Output of surfaces (most powerful to least powerful) is:

• Point (most powerful), concave face, convex back, and lateral surfaces (least)

Tip Geometry

• Defined by number of planes that the shank of the tip crosses.

Tip Selection

• Common tip selections are FSI 10, FSI 100, FSI 1000, THINSert, FSI SLI 1000, FSI SLI straight, FSI SLI Right, FSI SLI Left, and Implant Insert.

Furcation Entrances on Maxillary and Mandibular First Molars

• Gracey Curet: 0.76mm
• Furcation 0.63mm
• Ultrasonic tip 0.55mm

Stroke Directions

• Vertical strokes
• Oblique strokes
• Circumferential strokes

Lateral Pressure

• Light grip
• Guides into pocket
• NO tip use

Tip extends beyond blue line

• Optimum Efficiency (Scale Away)

Tip touches blue Line

• 25% Efficiency Loss (Reorder)

Tip touches red line

• 50% Efficiency Loss (Discard)

New Insert details

• Active Length = 4.2mm
• Efficiency is 100%

Worn Insert (25% Blue Line) details

• Active Length = 3.1 mm
• Efficiency is 75%

Maintenance Checks

• Check tips for wear before EVERY use
• Ensure all equipment is working correctly
• Ensure there is enough water
• Ensure inserts are not bent

Piezon Maintenance Checks

• Piezo tips will disappear down the drain, in a flash!
• Ensure the tip is tighened correctly

Bent, broken or separated stacks

• DO NOT USE

Where did that PDS tip go?

• A fractured tip within the mouth is a serious cause of concern.
• It could be wedged in a periodontal pocket, swallowed, spat out, or inhaled
• If the tip cannot be found, the patient will have to undergo a chest x ray

Insert and Handpiece Cleaning

• Reprocess as soon as possible
• Remove insert from the handpiece
• Remove handpiece from the cable
• Wipe/rinse thoroughly
• Remove excess soil
• Check for signs of visible contamination

Insert cleaning methods:

• Ultrasonic bath: Water bath for 15 minutes OR pH neutral cleaning solution for 15 minutes
• Follow manufacturer's instructions observing concentration rates and contact times

Insert malfunctions include:

• Overheating
• Improperly adjusted water
• Not filling handpiece with water prior to insert insertion
• Use of an unserviceable insert
• Water source

Common problems

• Clogged water requires clearing clog with Finger Spreader
• Leaking water require O-ring replacement

Comparison of Ultrasonic Scalers

• Magnetostrictive operates at 20 - 40 kHz, elliptical stroke pattern, metal rod or stack of metal sheets energy conversion, and power dispersion on all surfaces.
• Piezoelectric operates at 29 - 50 kHz, linear stroke pattern, crystals activated by ceramic handpiece for energy conversion, and power dispersion only active on lateral sides.

Sonics

• Sonic scalers are air-turbine units that operate at low frequencies ranging between 3000 and 8000 cycles per second
• Tip movement is general orbital
• Sonic scalers have a high intensity noise level because of the release of air pressure needed for movement of the tip of the sonic hand-piece

Final Safety Check

• Always remove/make safe the Power Driven Scaler between use, even for a few minutes!
• Never leave the tip pointing upwards
• Never leave it uncovered
• A needle stick accident waiting to happen!