Question 1

Precision thin inserts are designed and indicated for which of the following?

Accepted Answer

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. Tenacious deposits usually require the use of a standard insert. If a light deposit is tenacious due to burnishing, a diamond-coated tip with an endoscope might be an option. The clinician should look for a thinner. Another option for the latter situation is a thinner working end recommended to be used with higher power.

Question 2

What parts of the working end surfaces of a magnetostrictive ultrasonic insert are adapted to the root of the tooth for debridement?

Accepted Answer

The lateral surfaces generate the least amount of energy. The back is safely adapted to the tooth. Although the back is used, the point is never used because it can damage the tooth or restored surface, resulting in unwanted surface alterations and sensitivity. The lateral surfaces are safely used, but the point is not safely used. The concave surface is generally not used. It generates the second most amount of energy, after the point, and would be difficult to adapt to root surfaces due to its shape. Again the concave surfaces are not used. As previously discussed, both of these surfaces are not used. They generate more energy than the lateral or back sides.

Question 3

Which one of the following is an indication for using a standard ultrasonic insert or tip?

Accepted Answer

Moderate or heavy dental calculus is exactly what standard inserts and tips are designed and recommended for because they are bulkier and larger than precision thin inserts. Generalized tobacco stain is an indication for ultrasonic instrumentation and standard inserts; however, light subgingival calculus is not an indication for a standard design, especially not in a child depending on age and maturation of tooth structures. Fine subgingival deposit in deep periodontal pockets is an indication for precision thin inserts or tips because the working end is narrower than standard designs and in some cases longer, and the calculus is located subgingivally in deep periodontal pockets, presumably pockets over 5 mm. Of course intrinsic tooth stain is not an indication for periodontal debridement of any type. Again, generalized tobacco stain could be an indication and so could a client of geriatric status; however, subgingival periodontal debridement is not an indication of a standard bulky design. Use of mechanized instrumentation with geriatric clients is indicated provided they do not have any contraindications. This case description is an exact indication for thin designs.

Question 4

Which of the following is the main difference between a manually tuned and an autotuned ultrasonic instrument or unit?

Accepted Answer

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. Both 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). Manually tuned and autotuned units refer to magnetostrictive units only; thus, these units require an insert to mechanically remove deposits. Piezoelectric units are all attuned.

Question 5

Which of the following are disadvantages of mechanized instrumentation when compared with hand-activated instrumentation?

Accepted Answer

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 acoustic microstreaming occur with mechanized instrumentation and not with hand-activated instrumentation. These are also all advantages and not disadvantages of using mechanized instrumentation. The water flow, however, can limit visibility when compared with hand-activated instrumentation. Increased efficiency is not a disadvantage to the client or dental hygienist. Efficacy is reported to be equivalent as measured by the long-term response of healing parameters. A blended approach, however, is probably best for thorough debridement. Time involved given equal intraoral conditions would seem to be less with the mechanized instruments. Cost is not a factor for the client; however, a cost advantage in relation to less wear on curets in the clinical environment might be noticed.

Question 6

What is the action created by the formation and collapse of bubbles in water by high-frequency sound waves surrounding an ultrasonic tip?

Accepted Answer

The definition given is that of cavitation. Cavitation results in lavage, the therapeutic washing of the periodontal pocket or sulcus that occurs with both the piezoelectric and magnetostrictive units. Acoustic microstreaming occurs because agitation of the fluids surrounding a rapidly vibrating ultrasonic working end has the potential to destroy or disrupt the oral biofilm. Clinical power is the ability of the instrument to remove dental calculus. Increasing the power increases the distance the working end moves and the length of the stroke. Mechanical action refers to the vibration of the ultrasonic instrument's working end. Amplitude is synonymous with clinical power.

Question 7

Which of the following is true about the correct adaptation of an ultrasonic working end to the tooth surface?

Accepted Answer

Fifteen degrees is the optimum angle of the working end to the tooth surface because it does not cause undesirable surface alterations such as striations that have depth and volume. If the working end is angulated at 45 to 60 degrees, the angle between the end 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 or 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 working end at a zero-degree angle. In this case the working end would not be adapting to calculus itself to remove it via mechanical vibration. This statement is inaccurate. The working ends of both types of units are adapted as close to 15 degrees to the tooth as possible.

Question 8

When a thin insert is used for ultrasonic periodontal debridement, what tuning is recommended?

Accepted Answer

Thin inserts or tips 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.

Question 9

Which of the following best describes the water spray that is recommended when precision thin inserts are used for nonsurgical periodontal therapy?

Accepted Answer

This description best describes "out of phase" tuning recommended for precision thin inserts and tips. A water spray adjusted "out of phase" appears as a fine mist with a water drip. This is how the clinician knows that the insert or 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. A narrow steady stream of water describes tuning neither "in phase" nor "out of phase." Large droplets of water over a large area are not appropriate for "out of phase" tuning needed with thin inserts. Fine droplets of water and a narrow stream of water covering a large area does not accurately describe "out of phase" tuning.

Question 10

One of the major differences between the piezoelectric ultrasonic instrument and the magnetostrictive ultrasonic instrument is which of the following?

Accepted Answer

One clear difference between magnetostrictive and piezoelectric units is the working end surfaces that are adapted to the tooth. The lateral and back surfaces are adapted on a magnetostrictive insert and the two lateral surfaces only are adapted on the piezoelectric tip. This is one difference between the two units. The purpose of the water is similar in both units although the motion of the piezoelectric transducer does not emit heat. Cavitation and atomization are produced by both units. Frequency can be the same for both ultrasonic units, particularly if the magnetostrictive unit is autotuned. The type of stoke employed is similar with both units. The power used for both types of units is similar. Both units have adjustable power controls.

Question 11

All of the following influence the energy emitted from the working end of an ultrasonic instrument except:

Accepted Answer

Water does not influence the energy emitted. The water is used to cool magnetostrictive instruments and for cavitation for all ultrasonic instruments. Pressure increases the effect of the working end on the root or crown. Too much pressure will cause the tip to dampen or stop. When too much pressure is used, calculus removal can be less effective. The longer the time of exposure on the same tooth surface, the greater the energy emitted. The greater the angle of application of the working end to the tooth, the greater the energy output. The tooth to working end angle should be 15 degrees or less. A square end emits more energy. Rounded working ends are preferred for light periodontal debridement to enhance comfort and prevent potential hard and soft-tissue trauma.

Question 12

Excessive cementum removal during periodontal debridement could result in which of the following?

Accepted Answer

Ultrasonic instrumentation and hand instrumentation both can create dentinal sensitivity if too much root surface, or cementum, is removed. This surface could be located subgingivally or be supragingival if recession has occurred. Caries is an infectious disease process that is not initiated by instrumentation. Cementum could be removed evenly, even with overinstrumentation, and root surface damage usually refers to striations or defects. Pulpitis is inflammation in the pulp of the tooth for various reasons. The immature pulp of children is cited as one reason that ultrasonic instruments are sometimes contraindicated in this age group of clients. The heat generated could negatively affect the pulp, although cases of pulpits have not been reported in recent literature. Enamel is not lost with periodontal debridement with hand or ultrasonic instruments provided it is a healthy tooth structure of sufficient hardness. Dental hygienists do not instrument compromised enamel (demineralized).

Question 13

Power-driven instrumentation produces all of the following modes of action except:

Accepted Answer

Ultrasonic instruments convert electrical energy to mechanized energy via a transducer that is part of the insert, not a transductor. 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 working end 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. Atomization is produced and is the water flow that contacts the moving working end resulting in fine droplets and a fine spray.

Question 14

What actually causes the working end of an ultrasonic insert or tip to vibrate?

Accepted Answer

The transducer is the part of the mechanized ultrasonic instrument where electrical energy is converted to mechanical energy, which in turn causes the working end to vibrate. The contraction and expansion of this part causes the working end 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 working end. The water flow is a byproduct of the unit for cooling, and flushing of the sulcus or periodontal pocket. The foot pedal of any unit starts the activation of the entire ultrasonic process; however, it alone is not responsible for the working end activation.

Question 15

Which of the following descriptions provides a visual cue to the clinician to correct the tuning of a standard ultrasonic insert?

Accepted Answer

Generally, the standard working ends 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 narrow steady stream of water is present, it is not adjusted "in phase" for the maximum energy output necessary to remove dental calculus efficiently. This description, large droplets of water, might occur in the tuning process and describes water when it is neither "in phase" nor "out of phase." Status of the insert or tip should be reassessed for cracks, O-ring maintenance on the insert, or other problems. This description describes tuning for the instrument toward the "out of phase" status, which is indicated for thin working ends. If a steady stream of water accompanies the water spray, the working end is not adjusted for maximum energy output needed for the standard designs.

Question 16

Which of the following describes the power (amplitude) of ultrasonic energy?

Accepted Answer

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. The direction of the stroke, once the working end is loaded onto the tooth appears to be elliptical in both types of ultrasonic units.

Question 17

Sensitivity experienced by a client during power-driven instrumentation is most likely due to which of the following?

Accepted Answer

Incorrect adaptation can create sensitivity. If the tooth-to-working end 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. Methodical activation tends to refer to the motions used to cover the root surface with periodontal debridement to ensure calculus and biofilm removal is thorough. Generally, as long as the working end is in motion at all times over the tooth, sensitivity should not be felt. Faster activation to smooth a tooth should not, in itself, create sensitivity. All stroke directions (vertical, horizontal, oblique) are appropriate as long as the proper tooth-to-working end angulation is maintained.

Question 18

All of the following are contraindications for use of ultrasonic instrumentation except:

Accepted Answer

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. This represents a contraindication based on limited research and clinical judgment. Cardiac disease with secondary pulmonary disease potentially puts the client at risk for aspiration of oral biofilm microorganisms that could adversely affect the systems. 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. Dysphagia for any reason would make it difficult for a client to tolerate ultrasonic instrumentation. Specific cardiac pacemakers may not be affected; however, caution is still advised. Finding out as much information about the cardiac device is recommended, along with a consultation to the appropriate medical professional if use is highly indicated.

Question 19

In which of the following ways could an ultrasonic working end cause an undesirable surface alteration?

Accepted Answer

Striations in the root surface could occur if the point is adapted to the tooth. Also, sensitivity could result. The point is pointed so it is contraindicated for adaptation. 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. The working end of the insert is adapted to the surface of the enamel or cementum at a 15-degree angle or less to prevent any undue striations from occurring to the tooth structure, particularly cementum covering the root.

Question 20

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?

Accepted Answer

The water that flows through the instrument cools the transducer and working tip. The tip generates frictional heat that needs to be cooled. In a piezoelectric unit cooling is not needed; however, water is used for all the other advantages. 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. The water does not remove calculus or biofilm per se; the mechanical energy at the working end does.

Quiz 27: Ultrasonic Instrumentation