This fact is from Periodontal Instruments in Periodontology. It is a commonly tested concept in NEET MDS examinations. Understanding this fact is crucial for answering MCQs correctly.
Gracey curettes = area-specific = single cutting edge
Gracey 7/8 = buccal lingual posteriors
Gracey 11/12 = mesial posteriors
Gracey 13/14 = distal posteriors
Ultrasonic scaling better than hand for deep pockets
Piezoelectric vs magnetostrictive ultrasonic devices.