Atlas · Plate XI · Instrumentation · 08
Ultrasonic and piezo scalers
Magnetostrictive units vibrate at about 18,000-45,000 cycles per second in an elliptical path with every tip surface active; piezoelectric units vibrate at 25,000-50,000 cycles per second in a linear path with the lateral surfaces most active. Use the side of the last 2-4 mm with feather-light pressure, never the point. Water cools the tip and flushes the pocket.
High-yield facts · 9
- Magnetostrictive units vibrate at about 18,000-45,000 cycles per second (commonly 25 or 30 kHz) with an elliptical (figure-8) tip path; all tip surfaces are active.T3
- Piezoelectric units vibrate at about 25,000-50,000 cycles per second with a linear path; the lateral surfaces are most active.T3
- Use the side of the last 2-4 mm of the tip with feather-light pressure, tip at 0-15 degrees to the tooth, constantly moving.T3
- Never point the tip straight at the tooth (gouging).T3
- Water cools the tip and gives lavage and cavitation (bubbles that disrupt bacteria).T3
- Thin (slim) tips at low to medium power reach deep pockets and furcations; standard tips at higher power remove heavy supragingival deposits.T3
- Worn tips lose efficiency: 1 mm of wear reduces efficiency about 25%, 2 mm about 50%; replace beyond that.T3
- Precautions: older unshielded pacemakers or ICDs (follow the manufacturer), infectious respiratory disease, swallowing problems, young children, porcelain and composite restorations, titanium without special tips.T3
- Reduce aerosols with high-volume evacuation, preprocedural rinse and appropriate PPE.S7T3
Facts are written in our own words; each tag links to its source. Values marked "sources vary" differ between references, so check the one your program uses.