1. The mechanism of action of ultrasonic debridement includes mechanical, irrigation, cavitation, and acoustic microstreaming. The primary mechanism of deposit removal is cavitation.
The mechanism of action of ultrasonic debridement includes mechanical, irrigation, cavitation, and acoustic microstreaming. The primary mechanism of deposit removal is mechanical. The high-frequency oscillating action of the blunt tip contacting the deposit (biofilm or calculus) mechanically disrupts or fractures the deposit.
George, M. D. (2020). Ultrasonic Instrumentation. In D. M. Bowen & J. A. Pieren, Darby and Walsh Dental Hygiene: Theory and Practice (5th ed., pp. 456-474). Elsevier.
2. Ultrasonic cavitation and acoustic microstreaming work synergistically to disrupt biofilm up to how many millimeters from the contact point of the ultrasonic insert tip?
Cavitation and acoustic microstreaming are biophysical phenomena that act synergistically to disrupt biofilm up to 0.5 mm from the point of contact of the ultrasonic insert tip.
George, M. D. (2020). Ultrasonic Instrumentation. In D. M. Bowen & J. A. Pieren, Darby and Walsh Dental Hygiene: Theory and Practice (5th ed., pp. 456-474). Elsevier.
3. The lavage produced by ultrasonic scalers removes loosely attached biofilm and endotoxin from the root surface, in addition to flushing debris from the treatment site.
Irrigation is utilized with ultrasonic instrumentation to reduce heat generated by friction from the oscillating tip contacting the tooth surface. In addition, the irrigation produces a lavage, which has been demonstrated to remove loosely attached biofilm and endotoxin from the root surface and flush debris from the treatment site.
George, M. D. (2020). Ultrasonic Instrumentation. In D. M. Bowen & J. A. Pieren, Darby and Walsh Dental Hygiene: Theory and Practice (5th ed., pp. 456-474). Elsevier.
4. Which of the following mechanisms of action are characterized by a vigorous swirling motion of fluid?
Acoustic microstreaming occurs near any object in oscillatory motion in liquid and is characterized by a vigorous swirling motion of fluid. This phenomenon occurs when implementing ultrasonic instrumentation. When acoustic microstreaming and cavitation occur together, they produce the energy that disrupts biofilm.
George, M. D. (2020). Ultrasonic Instrumentation. In D. M. Bowen & J. A. Pieren, Darby and Walsh Dental Hygiene: Theory and Practice (5th ed., pp. 456-474). Elsevier.
5. A piezoelectric ultrasonic scaler insert is composed of a stack of thin nickel strips soldered together at the ends and attached by a connecting body to a tip. A magnetostrictive ultrasonic scaling insert contains a crystalline (ceramic or quartz) disc.
A magnetostrictive ultrasonic scaling insert is composed of a stack of thin nickel strips soldered together at the ends and attached by a connecting body to a tip. A piezoelectric ultrasonic scaler insert contains a crystalline (ceramic or quartz) disc that expands and then contracts in response to an alternating application of current, producing vibrations that result in high-frequency oscillations of the tip.
George, M. D. (2020). Ultrasonic Instrumentation. In D. M. Bowen & J. A. Pieren, Darby and Walsh Dental Hygiene: Theory and Practice (5th ed., pp. 456-474). Elsevier.
6. When utilizing ultrasonic scalers, which of the following should be implemented for proper aerosol management?
Aerosol management during ultrasonic instrumentation includes:
- Barrier protection: Personal barrier protection for the clinician and patient and surface barrier protection of clinical contact surfaces that cannot be cleaned by sterilization or disinfection.
- Preprocedural rinsing: An essential oil antiseptic rinse or 0.12% chlorhexidine gluconate rinse has been shown to reduce the bacterial count in the aerosol generated by ultrasonic scaler use.
- Retracting the patient's lip or cheek: Pulling out the patient's lip or cheek, then up/down (lips) or forward (cheek), forms a cup that helps contain the aerosol to the oral cavity where it can be evacuated.
- High-volume evacuation (HVE): HVE should be used during the entire debridement procedure to remove as much of the aerosol as possible and minimize the amount that escapes the operative site.
George, M. D. (2020). Ultrasonic Instrumentation. In D. M. Bowen & J. A. Pieren, Darby and Walsh Dental Hygiene: Theory and Practice (5th ed., pp. 456-474). Elsevier.
