Chapter 27- Ultrasonic Instrumentation
Q. All of the following influence the energy emitted from the working end of an ultrasonic insert except one. Which one is the exception? A. Pressure B. Time of exposure C. Angle of application D. Amount of water
Amount of water Feedback Water does not influence the energy emitted. The water is used to cool magnetostrictive and sonic mechanized instruments and for cavitation for all mechanized instruments. Pressure increases the effect of the insert tip. Too much pressure will cause the tip to dampen or stop. The longer the time of exposure on the same tooth surface, the greater the energy emitted. The greater the angle of application of the insert tip to the tooth, the greater the energy output.
Q. What parts of the working end surfaces of a magnetostrictive ultrasonic insert are adapted to the root of the tooth for debridement? A. Back and point B. Point and lateral surfaces C. Back and lateral surfaces D. Concave surface and back
Back and lateral surfaces Feedback The lateral surfaces generate the least amount of energy. The back is safely adapted to the tooth; however, the point is never used because it can damage the tooth or restored surface, resulting in surface damage, alterations, and sensitivity. The lateral surfaces are safely used, but the point is not safely used. The concave surface is not used because it is not an active tip area.
Q. A combination of manual and mechanized instrumentation is recommended to obtain optimal results from periodontal debridement. Advantages of mechanized instrumentation over hand-activated instrumentation include increased efficiency, water for lavage, and less pressure at times. A. Both statements are true. B. Both statements are false. C. The first statement is true, and the second statement is false. D. The first statement is false, and the second statement is true.
Both statements are true. Feedback A combination of manual and mechanized instrumentation is recommended to obtain optimal periodontal debridement and clinical outcome. Research has not established that use of mechanized instrumentation alone is better than the use of manual instrumentation. Advantages of mechanized instrumentation over hand-activated instrumentation include increased efficiency, water for lavage, and less pressure at times. Both statements are client education issues discussed in Chapter 25.
Q. What is the action created by the formation and collapse of bubbles in water by high-frequency sound waves surrounding an ultrasonic insert tip? A. Clinical power B. Mechanical action C. Cavitation D. Acoustic microstreaming
Cavitation Feedback The definition given is that of cavitation. Cavitation results in lavage, the therapeutic washing of the periodontal pocket or sulcus. Acoustic microstreaming occurs because agitation of the fluids surrounding a rapidly vibrating ultrasonic tip has the potential to destroy or disrupt the oral biofilm. Clinical power is the ability of the instrument to remove dental calculus. Mechanical action refers to the vibration of the ultrasonic instrument's working tip.
Q. All of the following are contraindications for use of mechanized instrumentation except one. Which one is the exception? A. Cardiovascular disease with secondary pulmonary disease B. Communicable diseases C. Multiple dystrophy with dysphagia D. Chronic pulmonary disease
Communicable diseases Feedback: Communicable diseases such as hepatitis, tuberculosis, strep throat, and respiratory infections could all be transmitted via aerosols. Nonsurgical periodontal therapy (NSPT) should not occur until the disease has been treated for an appropriate length of time as determined in consultation with the physician of record. When it is determined that it is appropriate for the patient to receive NSPT, standard precautions are employed to meet infection-control guidelines. The rest of the responses do represent contraindications based on limited research and clinical judgment. Chronic pulmonary disease such as asthma, emphysema, cystic fibrosis, and pneumonia all probably increase the risk for infection if microorganisms in oral biofilm are aspirated into the lungs. Cardiac disease with secondary pulmonary disease again potentially puts the client at risk for aspiration of oral biofilm microorganisms that could adversely affect the cardiovascular system.
Q. All of the following are true about activation of mechanized instruments except which one? A. The insert is in motion at all times. B. Overlapping and multidirectional strokes are used. C. Excessive lateral pressure is used. D. Immediate outcome from instrumentation is evaluated using the dental light, air, and a periodontal explorer.
Excessive lateral pressure is used. Feedback This is not true about activation of mechanized instruments. In fact, excessive lateral pressure is never recommended because it could cause undesirable surface alterations and sensitivity. Only light lateral pressure is applied, as the mechanical action of the instrument itself removes deposit, oral biofilm, and endotoxins. The remainder of the answers are true regarding activation of mechanized instruments.
Q. Sonic instruments differ from ultrasonic instruments in which of the following? A. Frequency of the mechanized instrumentation B. Motion of the tip C. Activated surfaces of the working end D. Purpose of the water
Frequency of the mechanized instrumentation Feedback The frequency of sonic instruments is much lower than that of ultrasonic instruments. Sonic instrumentation is actually air turbine driven, and the frequency is from 2500 to 7000 cycles per second. The frequency of ultrasonic instruments (magnetostrictive or piezoelectric units) ranges from 25,000 to 50,000 cycles per second. The motion of the tip of the sonic instrument is similar to that in the magnetostrictive unit (elliptical), the activated surfaces of the working end are the same as in the magnetostrictive unit (all), and the purpose of the water is for cooling, which is the same as in the magnetostrictive ultrasonic instrument.
Q. Sensitivity experienced by a client during mechanized instrumentation is most likely due to which of the following? A. Fulcrum placement B. Incorrect adaptation C. "Vibrato" or fast activation D. Inappropriate stroke direction
Incorrect adaptation Feedback Incorrect adaptation can create sensitivity. If the tooth-to-tip angle is greater than 15 degrees, energy is emitted that can create sensitivity. Intraoral or extraoral fulcrum placement should not affect sensitivity, although extraoral fulcrum placement facilitates lighter pressure with precision thin inserts. Faster activation is indicated to smooth a tooth and should not, in itself, create sensitivity. All stroke directions (vertical, horizontal, oblique) are appropriate.
Q. Which of the following describes the power (amplitude) of ultrasonic energy? A. It is the length of the stroke. B. It adjusts the volume of water. C. It is how fast the stroke moves. D. It is the speed of movement across the tooth.
It is the length of the stroke. Feedback A clinician who adjusts the power is affecting the length of the stroke itself. Increasing the power setting increases the distance the working end moves. The distance the working end travels in the single vibration is called tip displacement. Power, or the power knob, is not related to the volume of water. The water knob adjusts the flow of water. How fast the stroke moves describes the frequency. Stroke speed across the tooth is controlled by the clinician and not the mechanized instrument.
Q. Precision thin inserts are designed and indicated for which of the following? A. Heavy calculus removal B. Light periodontal root debridement C. Removal of extrinsic tooth stain only D. Removal of orthodontic cement
Light periodontal root debridement Feedback Precision thin inserts were designed for light periodontal debridement (for subgingival access, client comfort, and tactile sensitivity). Because they are narrower in diameter than standard designs, they are generally used with less power (and frequency) than standard inserts. Heavy calculus removal is accomplished with standard inserts. Extrinsic tooth stain occurs supragingivally; therefore a standard insert is usually indicated. Orthodontic cement is tenacious and therefore must be removed with a standard insert.
Q. Which one of the following is an indication for using a standard ultrasonic insert? A. Generalized tobacco stain or localized light subgingival moderate calculus in a child B. Moderate to heavy supragingival calculus in a young adult, accompanied by tobacco stain C. Fine subgingival deposit in deep periodontal pockets and intrinsic tooth stain D. Light generalized tobacco stain and fine subgingival scaling generalized in the mouth of a senior citizen
Moderate to heavy supragingival calculus in a young adult, accompanied by tobacco stain Feedback Moderate or heavy dental calculus is exactly what standard inserts are designed and recommended for because they are bulkier and larger than precision thin inserts. Localized light subgingival dental calculus is contraindicated because of the type of calculus; also, the child client is a precaution because of large pulp chambers. The best insert tips for light subgingival calculus are precision thin inserts. Generalized tobacco stain is an indication for ultrasonic instrumentation and standard inserts; however, intrinsic tooth stain of any type is not an indication because this stain cannot be removed by instrumentation. Fine subgingival deposit in deep periodontal pockets is an indication for precision thin inserts because the tips are narrower than standard tips and in some cases longer and the calculus is located subgingivally in deep periodontal pockets, presumably pockets over 5 mm. Use of mechanized instrumentation with geriatric clients is indicated provided they do not have any contraindications related to age alone.
Q. Which of the following are disadvantages of mechanized instrumentation when compared with hand-activated instrumentation? A. Increased efficiency, no need to sharpen, reduced lateral pressure B. Less tissue distention, lavage, acoustic microstreaming C. Water, increased efficiency, and increased lateral pressure D. More precautions and limitations, aerosol production, possible temporary hearing shifts
More precautions and limitations, aerosol production, possible temporary hearing shifts Feedback Because of aerosol production and mechanized tip action, there are potentially more precautions and contraindications than with hand-activated instrumentation. Also, temporary hearing shifts have been documented; however, more research is needed. Increased efficiency, no need to sharpen, and reduced lateral pressure are all advantages of mechanized instrumentation. Less tissue distention, lavage, and potential acoustic microstreaming occur with mechanized instrumentation than with hand-activated instrumentation. These are also all advantages and not disadvantages of using mechanized instrumentation. The water flow or cavitation, however, can limit visibility when compared with hand-activated instrumentation.
Q. When a precision thin insert is used for ultrasonic scaling, what tuning is recommended? A. Out of phase B. In phase C. Neither of the above D. Both out of phase and in phase tuning are routinely used
Out of phase Feedback Precision thin inserts are generally used detuned from resonance frequency. "Out of phase" represents a fine water spray mist with a water drip. Out of phase tuning is thought to enhance client comfort and results in less vibration for debridement procedures for which precision thin inserts are indicated. More vibration, or tuning "in phase," is probably needed for removal of heavier dental calculus deposits.
Q. In which of the following ways could an ultrasonic tip cause an undesirable surface alteration? A. Power setting is too low. B. Water spray is too great. C. Point is adapted to the tooth. D. Light pressure is used on the tooth.
Point is adapted to the tooth. Feedback: The tip of the insert is adapted to the surface of the enamel or cementum at a 15-degree angle to prevent any undue striations from occurring to the tooth structure, particularly cementum covering the root. Striations in the root surface could occur if the point is adapted to the tooth. Also, sensitivity could result. A power setting that is too low will not cause undesirable surface alterations; however, the power may not be high enough to remove the type of deposit present depending on its size and tenacity. Strong water spray will not have an effect on the tooth surface. Light pressure on the tooth surface is what is recommended. Too much pressure could cause undesirable surface alterations.
Q. One of the major differences between the piezoelectric ultrasonic instrument and the magnetostrictive ultrasonic instrument is which of the following? A. The purpose of the water that is emitted at the tip B. The activated surfaces of the working end C. The frequency used D. The type of stroke employed when activating
The activated surfaces of the working end Feedback One clear difference between magnetostrictive and piezoelectric units is the surfaces that are activated at the working end of the insert. All surfaces are activated on the tip of the magnetostrictive insert. The working end of the piezoelectric ultrasonic is activated on two lateral sides. This is one difference between the two units. Another difference is that the motion of the insert is elliptic or orbital with the magnetostrictive unit and linear with the piezoelectric unit. The purpose of the water and the frequency and type of stoke employed are similar with both units.
Q. Which of the following is the main difference between a manually tuned and an autotuned ultrasonic instrument or unit? A. The manually tuned instrument has less "clinical power" than the autotuned instrument. B. The autotuned unit has a preset frequency, and the manually tuned unit does not. C. The manually tuned unit does not require water as a coolant, but the autotuned unit does. D. Amplitude is greater with the autotuned unit than with the manually tuned unit.
The autotuned unit has a preset frequency, and the manually tuned unit does not. Feedback The autotuned unit has a preset frequency, and the manually tuned unit does not. The preset frequency within the autotuned unit tunes the cycles per second; therefore there is no frequency knob. Manually tuned and autotuned ultrasonic instruments have "clinical power," referring to their ability to remove calculus under load. Both autotuned and manually tuned magnetostrictive ultrasonic scaling units require water as a coolant; piezoelectric ultrasonic scaling units, in general, do not require water as a coolant. Both autotuned and manually tuned units have amplitude (also known as power).
Q. All of the following are verified health-related issues or outcomes associated with mechanized instrumentation except one. Which one is the exception? A. Interproximal areas, furcations, the cementoenamel junction, and multirooted teeth will most likely exhibit residual calculus regardless of instrument method. B. Bleeding on probing and probing depths are both reduced to equivalent levels when sonic and ultrasonic methods are compared with each other and with manual scaling. C. The best results from nonsurgical periodontal therapy occur with the use of mechanized instrumentation versus manual instrumentation or a combination of both. D. Longitudinal studies are needed to evaluate clinical parameters such as clinical attachment levels after mechanized instrumentation.
The best results from nonsurgical periodontal therapy occur with the use of mechanized instrumentation versus manual instrumentation or a combination of both. Feedback Research suggests that probably a combination of ultrasonic, sonic, and hand-activated instrumentation provides the best results for nonsurgical periodontal therapy. All the rest of the responses are true health-related issues or outcomes as evidenced by research. Also, more longitudinal research is needed to evaluate clinical parameters such as clinical attachment levels after mechanized instrumentation.
Q. Hand-activated and mechanized instrumentation are equally effective in removing subgingival oral biofilm and dental calculus. The effort to remove endotoxin is also equal with hand-activated and mechanized instrumentation. A. Both statements are true. B. Both statements are false. C. The first statement is true, and the second statement is false. D. The first statement is false, and the second statement is true.
The first statement is true, and the second statement is false. Feedback Literature reveals that hand-activated and mechanized instrumentation are equally effective in removing subgingival oral biofilm and dental calculus. However, endotoxin is probably removed more easily and quickly with mechanized instrumentation when compared with hand-activated instrumentation because of the powered actions (cavitation, lavage, microstreaming).
Q. What actually causes the tip of an ultrasonic insert to vibrate? A. The voltage in the generator B. The transducer contracting and expanding C. The cavitation D. Acoustic microstreaming
The transducer contracting and expanding Feedback The transducer is the part of the mechanized ultrasonic instrument where electrical energy is converted to mechanical energy, which in turn causes the tip to vibrate. The contraction and expansion of this part causes the tip to vibrate. The transducer is located within the handpiece and is a stack of metal strips in a magnetostrictive unit and a ceramic rod in a piezoelectric unit. Cavitation and acoustic microstreaming are both related to the water flow, which does not cause the vibration of the tip. The water flow is a byproduct of the unit for cooling, and flushing of the sulcus or periodontal pocket.
Q. Which of the following is true about the correct adaptation of an ultrasonic insert tip to the tooth surface? A. The working end is angulated at more than 45 degrees and less than 60 degrees. B. The working end should be angulated at 15 degrees or almost parallel to the long axis of the tooth. C. The working end is angulated at 60 degrees to 80 degrees to the tooth surface. D. The tip of the working end is angulated at zero degrees to the tooth surface.
The working end should be angulated at 15 degrees or almost parallel to the long axis of the tooth. Feedback Fifteen degrees is the optimum angle of the tip to the tooth surface because it does not cause undesirable surface alterations such as striations that have depth and volume. If the tip is angulated at 45 to 60 degrees, the angle between the tip and the tooth is too great and undesirable root surface alterations can occur. This is the recommended angle for the curet blade to be adapted to the tooth surface when the tooth surface is smoothed (root debridement or root planing). If an ultrasonic insert tip were adapted at a 60- to 80-degree angle, the depth of the striation and volume of the striation (stroke) it caused might be too great. This angulation is recommended for a working stroke with a curet to remove calculus deposits. It would be nearly impossible to adapt the ultrasonic tip at a zero-degree angle. In this case the tip would not be adapting to calculus itself to remove it via tip vibration.
Q. When magnetostrictive ultrasonic instrumentation is used, the function of the water that circulates through the handpiece and exits as a spray at the working end is which of the following? A. To lubricate the moving parts of the handpiece B. To cool the transducer and the tip C. To stop bleeding D. To destroy or disrupt bacteria
To cool the transducer and the tip Feedback The water that flows through the instrument cools the transducer and working tip. The tip generates frictional heat that needs to be cooled. The water does not lubricate, and the instrument itself needs no lubrication. The water flow does reduce bleeding; however, it does not stop bleeding. Acoustic microstreaming is the term that describes the potential to destroy or disrupt bacteria by agitation in the fluids that surround the rapidly vibrating ultrasonic tip. It is a byproduct of the water that is needed to cool the system.
Q. Mechanized instrumentation has all of the following modes of action except one. Which one is the exception? A. Cavitation B. Transduction C. Mechanical action D. Acoustic microstreaming
Transduction Ultrasonic instruments convert electrical energy to mechanized energy via a transducer that is part of the insert, not a transductor. This feature is not one of the three modes of action of mechanized instruments. Cavitation is the action created by the formation and collapse of bubbles in water by high-frequency sound waves surrounding a mechanized tip, resulting in lavage and irrigation. Mechanized action is the vibration of the tip of the insert that results in deposit removal. Acoustic microstreaming is the destruction or disruption of bacteria by the agitation of the fluids surrounding a rapidly vibrating power-driven tip.
Q. Which of the following necessitate precautions when mechanized instrumentation is used? A. Unshielded pacemakers, demineralized tooth surfaces, and children B. Tobacco stain, orthodontic cement, and pericoronitis C. Necrotizing periodontal diseases, communicable diseases, and immunosuppression D. Periodontal debridement, dysphagia, and intrinsic tooth stain
Unshielded pacemakers, demineralized tooth surfaces, and children Feedback Each of these factors is an indication for caution during use of mechanized instruments. None of these factors necessarily contraindicates the use of mechanized instruments. Instead, caution is used. For example, unshielded pacemakers may be disrupted by external electric fields such as that generated with the magnetostrictive unit. Older models of pacemakers were unipolar and less insulated from dental equipment. Newer shielded models are bipolar and well insulated; therefore the small amount of electromagnetic radiation generated by dental equipment does not threaten their function. Consultation with a cardiologist of record will provide information on the pacemaker type and recommendations for use of magnetostrictive ultrasonic instrumentation. Demineralized tooth surfaces are avoided with mechanized instrumentation. Mechanized instrumentation can occur adjacent to demineralized areas. Use of mechanized instrumentation with children is a concern because vibrations might negatively affect young growing tissue. Primary and newly erupted teeth have large pulp chambers that are more susceptible to heat generated by dental instruments. If mechanized instruments are used, the lowest possible power setting and adequate water flow for cooling are recommended.
Q. Which of the following descriptions provides a visual cue to the clinician to correct the tuning of a standard ultrasonic insert? A. A narrow steady stream of water B. Very fine droplets of water covering a large area C. Large drops of water covering a large area D. Fine droplets of water and a narrow stream of water covering a large area
Very fine droplets of water covering a large area Feedback: Generally, the standard insert should be adjusted to a resonance frequency for maximum energy output. This level of tuning puts the insert at peak efficiency suitable for light to heavy deposit (dental calculus) removal. The covering of a large area by very fine droplets is a way to describe the widest spray of mist that the operator is striving to achieve when the frequency is adjusted "in phase" for a standard insert. If a stream of water accompanies the water spray, the insert is not adjusted for maximum energy output. Likewise, if a narrow steady stream of water is present, the insert is not adjusted "in phase" for maximum energy output necessary to remove dental calculus efficiently.
Q. Which of the following best describes the water spray that is recommended when precision thin inserts are used for nonsurgical periodontal therapy? A. A narrow steady stream of water B. Large droplets of water over a large area C. Very fine droplets of water in a fine mist or spray D. Fine droplets of water and a narrow stream of water covering a large area
Very fine droplets of water in a fine mist or spray Feedback: This description best describes "out of phase" tuning recommended for precision thin inserts. A water spray adjusted out of phase appears as a fine mist with a water drip. This is how the clinician knows that the tip is not tuned to resonance frequency for maximum energy output. Maximum energy output is not needed for periodontal debridement accomplished with precision thin inserts.
