Sonic & ultrasonic instruments
- 1. SONIC & ULTRASONIC INSTRUMENTS Dr. Shikha Arya Dr. Nikita Kharkongor
- 2. CONTENTS: o History o Ultrasound ?? o Factors involved in M.O.A o Mode of action o Efficacy & clinical outcomes o Indications o Types of power scalers o Ultrasonic instrumentation. o Types of insert tips o Tip wear , care & maintenance o U/S associated hazards o Conclusion
- 3. WHAT LEDTOTHE DISCOVERY OF POWER DRIVEN SCALERS ??
- 4. Humans can hear sound at frequencies up to 20,000 Hz or 20 kHz. ULTRASONIC – Of or involving sound waves with a frequency above the upper limit of human hearing i.e., greater than 20 Khz Ultrasound is used in many different fields, typically to penetrate a medium and measure the reflection signature (e.g., sonography used in obstetrics) or to supply focused energy (e.g., ultrasonic cleaning of jewelry)
- 5. WHAT FACTORS INVOLVED IN M.O.A. OF POWER SCALERS ?? FREQUENCY • No of times per second an insert tip moves back & forth during one cycle in an orbital, elliptical, or linear stroke path • It determines the active area of the tip. • 25khz=25,000 times per second (i.e., moving tip). • Increased frequency = lesser active area of scaler tip. STROKE • The maximum distance the insert tip travels during one cycle. • Amplitude = one half of distance of the stroke. • Power knob controls stroke length of insert tip during one cycle. • power knob = distance the tip travels.(frequency =constant) • High power =longer stroke, lower power = shorter stroke. WATER FLOW • Water contributes to three physiologic effects , thereby enhancing efficacy of power scalers: • Acoustic streaming • Acoustic turbulence • Cavitation FREQUENCY ACTIVE TIP 25Khz Terminal 4.3mm 30khz Terminal 4.2 mm 50khz Terminal 2.3mm
- 6. MODE OF ACTION : Acoustic streaming Acoustic turbulence Cavitation Lavage • Unidirectional fluid flow caused by ultrasound waves.• Is created when the movement of the tip causes the coolant to accelerate, producing an intensified swirling effect. • This turbulence continues until cavitation occurs. • Formation of bubbles in water caused by the high turbulence. • The bubbles implode and produce shock waves in the liquid creating further shock waves throughout the water. Refers to flushing of the sulcus, disruption of plaque biofilms, and removal of necrotic tissue and blood.
- 7. EFFICACY AND CLINICAL OUTCOMES : Efficacy and clinical performance have been evaluated under following parameters : • Plaque and calculus removal • Bacterial reduction and endotoxin/ cementum removal • Smooth root surface • Reduction in bleeding on probing , probing depth , and a gain in a clinical attachment • Ability to access furcation.
- 8. INDICATIONS: Removal of supragingival calculus and tenacious stains Subgingival debridement: Removal of calculus, attached biofilm and endotoxins from the root surface Removal of unattached biofilm from sulcular space Removal of orthodontic cement i.e., debonding Removal of overhanging margin of restorations
- 9. SONIC SCALERS • 2500-7000 Cps , Elliptical motion , all sides active ULTRASONIC SCALERS • MAGNETOSTRICTIVE • PIEZOELECTRIC 25000- 50000 cps , Linear motion, Lateral sides active 18000-45000 cps. Elliptical motion All sides active POWER DRIVEN SCALERS
- 10. SONIC SCALERS: Device is composed of : 1. Hand piece 2. Interchangeable scaling tips • Driven by compressed air. • Less amplitude than ultrasonic. • Produces vibrations at tip between 2500 to 7000 cps.
- 11. They create less heat at the scaling tip than an ultrasonic machine. Used with air pressure so no need for separate installation as in case of ultrasonic machine.They are noisy during use These have a low range of vibration and high tip amplitude as compared to ultrasonic scalers. A low range of vibration and high tip amplitude hardly ever leads to cavitation of water jet. ADVANTAGES DISADVANTAGES
- 12. PARTS OF AN ULTRASONIC SCALER :
- 13. COMPARISON OF POWER SCALERS :
- 15. MAGNETOSTRICTIVE SCALERS: These scalers have a metal stack containing of Ni – Fe alloy strips or a ferrite insert inserted in the handpiece. Live coil present inside the handpiece generates an alternating electromagnetic field causing expansion or contraction of ferromagnetic material resulting in vibrations which are conducted at scaler tip. The first magnetostrictive ultrasonic scaler was released in 1957 by Cavitron, Dentsply
- 16. Figure 3.2 Diagram of a magnetostrictive insert. Application of an electromagnetic field to the stack of nickel strips results in magnetostriction – elongation then contraction – of the nickel stack along its length, producing longitudinal vibrations Figure 3.3 Longitudinal vibrations travel from the nickel stack through a connecting body to the tip of the insert.
- 17. Composed of a stack of thin nickel strips soldered together at the ends and attached by a connecting body to a tip Holds the insert to surround the nickel stack in a spiral of copper wire which generates a magnetic field upon application of electrical current, resulting in magnetostriction of the stack The handpiece of a magnetostrictive unit contains a spiral of copper wire (visible in the lower, cut-out handpiece), which surrounds the stack once the insert is seated in the handpiece A magnetostrictive insert
- 18. PIEZOELECTRIC SCALERS : The first piezoelectric device was introduced in market in 1970 by Satelec . In piezoelectric units the electrical energy is applied to ceramic crystals. This causes changes in the crystal lattice shape and the alternate expansion and compression of the ceramic discs results in Micro movement of the tip. Piezoelectric scalers rely upon linear movement. Given the linear fashion in which the tip moves, it is the tip’s two lateral surfaces that are the most active. Tip moves in a linear pattern i.e., back & forth motion.
- 21. ULTRASONIC INSTRUMENTATION : Adaptation Angulation Lateral pressure Working Stroke Insertion Grasp Fulcrum
- 22. Principle Ultrasonic instrumentation Hand instrumentation Adaptation Adapt any surface of the active tip Vertical orientation Horizontal orientation (interproximal surfaces only) Adapt lateral surface of toe/tip Oblique orientation Angulation 0–15° to tooth surface 45–90° to tooth surface Lateral pressure Light pressure applied to maintain contact with tooth Moderate pressure applied to eng cutting edge Working Stroke Constant and varied in direction Intermittent and apico-coronal in direction Insertion At gingival margin or outer edge of deposit Below deposit Grasp Light standard pen Firm modified pen Fulcrum Established at a distance from treatment site for stabilization Established in immediate treatme to leverage working stroke
- 23. Adaptation technique Description Indication for use Vertical (Parallel) Active area of tip is parallel to long axis of tooth, with point of tip directed apically, toward base of the pocket Instrumentation of all subgingival and supragingival surfaces (excluding interproximal spaces) using any surface of the tip Horizontal (Perpendicular) Active area of tip is perpendicular to the long axis of the tooth Instrumentation of interproximal space using back or face of the tip Oblique Active area of a lateral surface is oblique to the long axis of the tooth Manual instrumentation; not recommended by authors for ultrasonic instrumentation ADAPTATION:
- 24. Angulation of the active area of the oscillating tip to the tooth surface being treated should be maintained between 0 and 15 degrees: as close to 0° as possible, but never exceeding 15° ANGULATION FOR ULTRASONICS FOR MANUAL INSTRUMENTATION Increasing (opening) this tip-tooth angulation beyond the recommended 0–15° increases the amount of root substance lost during sonic and ultrasonic instrumentation.
- 25. The amount of lateral pressure to apply to the oscillating tip varies according to the type of deposit to be removed, ranging between 0.5 N and 2.0 N. Forces below this range (<0.5 N) may inhibit the clinician’s ability to maintain continuous adaptation of the tip to the tooth. Forces above this range (>2 N) affect the efficiency of deposit removal and the amount of root surface damage. Strong lateral pressure : More scratching Cementum removal Dentin exposure. LATERAL PRESSURE : FORCE in manual instrumentation : between 1.01 and 15.73 N
- 26. WORKING STROKES:
- 27. INSERTIO N:
- 28. GRASP: To make sure you have the correct grasp and placement, balance the handle between your thumb and index finger in a position where little or no assistance is required. At that point, bring thumb and index finger together and grasp only tightly enough to keep it in place. During scaling, the grasp should always be very light so that maximum efficiency is achieved. Having a light grasp ensures that you are maintaining light lateral pressure,
- 29. FULCRUMS :
- 30. For removal of Heavy tenacious calculus . INSERTTIPS
- 34. TIPWEA New Insert Active Length = 4.2mm Efficiency is 100% Worn Insert 25% (Blue Line) Active Length = 3.1 mm Efficiency is 75% 4.2mm Active length 3.1mm Active length Tip wear reduces efficiency
- 36. PRECAUTIONS Damage to integrity of restoration Porcelain- fracture, loss of marginal integrity Amalgam – surface defects Composite –surface alteration Titanium implant abutments Deciduous teeth. Demineralized tooth structure.
- 37. U/S ASSOCIATED HAZARDS : Aerosol production Cardiac pacemakers
- 39. Preventive measures : •Personal protective barriers. •Routine use of preprocedural antiseptic rinse ( listerine or CHX for 1min). •High volume suction : can reduce upto 90 - 98% aerosols
- 41. Initial pacemakers were more susceptible to the external electromagnetic field as their circuit was not shielded Current pacemakers are relatively immune to electromagnetic interference because the circuitry is shielded inside a sealed titanium or stainless steel case that often has an additional insulative coating. Piezoelectric ultrasonic devices do not interfere with pacemaker functioning.
- 42. CONTRAINDICATIONS : Communicable diseases: patients with a communicable disease that can be transmitted by aerosols, such as TB. Susceptibility to infection : Immunosuppression from disease or chemotherapy, uncontrolled diabetes, kidney or other organ transplant. Dysphagia Cardiac tissues (pacemakers).
- 43. Increased efficiency Biofilm disruption No need to sharpen instruments. Reduced lateral pressure required Easy to debride inaccessible furcation areas. Reduced operator fatigue DISADVANTAGES ADVANTAGES oLess tactile sensation oPotential occupational hazards oAerosol production oReduced visibility oRequires power supply
- 44. CONCLUSION : Power scalers have emerged from being adjuncts for removing heavy supragingival calculus to a tool that may be used for all aspects of scaling , deplaquing, supragingival scaling. Power scalers may produce more aerosols than hand instruments, but appropriate universal precautions minimize the risk to the patient and clinician.
- 45. REFRENCES :Carranza (10th & 11th edition) Periobasics.com http://www.ultrasonics.org (University of Birmingham) www.dentsplysirona.com www.pocketdentistry.com www.hufriedy.com
- 46. THANKYOU
Editor's Notes
- #16: Electrical energy is applied to the Hand piece of the device and this generates magnetic energy. The magnetic energy is applied to the insert’s stacked metal strips, which converts energy from the hand piece into mechanical oscillations that activates tip Magnetostrictive scalers rely on the elliptical movement of the insert tip. Magnetostrictive technology results in all surfaces of the insert being active; this allows more flexibility in adaptation to the tooth surface. However, the most active area of the insert’s tip is the point and the lateral surfaces are the least active. The length of the active tip varies according to the energy output and frequency at which the ultrasonic device operates.
- #19: Quartz is not conductive.(it doesn’t carry electricity like most metals ) Piezoelectric materials are non-conductive materials which generate electricity when u subject them to pressure . They undergo physical deformation when u run electricity thru them. Rochelle salts,
- #20: In ultrasonic dental devices with a piezoelectric transducer, an alternating electrical current is applied across a ceramic or quartz disk (Figure 3.9). In response to the alternating application of current, the crystalline structure alternatingly expands then contracts, producing vibrations that result in high-frequency oscillation of the tip (Laird and Walmsley, 1991) (Figure 3.10).