The objective of scaling and root planing, otherwise known as conventional periodontal therapy or non-surgical periodontal therapy, is to remove or eliminate the etiologic agents which cause inflammation: dental plaque, its products and calculus, thus helping to establish a periodontium that is free of disease. Periodontal scaling procedures "include the removal of plaque, calculus and stain from the crown and root surfaces of teeth, whereas root planing is a specific treatment that removes the roughened cementum and surface dentin that is impregnated with calculus, microorganisms and their toxins." Scaling and root planing are often referred to as deep cleaning, and may be performed using a number of dental tools, including ultrasonic instruments and hand instruments, such as periodontal scalers and currettes.
Removal of adherent plaque and calculus with hand instruments can also be performed on patients without periodontal disease. This treatment would then be referred to as a prophylaxis (a cleaning, although literally, it means "prevention"), or a prophy for short. Sometimes this device may be electric, known as an ultrasonic or sonic scaler. At present though, there is inadequate research evidence to claim that periodic pre-emptive scaling reduces the incidence of periodontal disease.
Sonic and ultrasonic scalers are powered by a system that causes the tip to vibrate. Sonic scalers are typically powered by an air-driven turbine. Ultrasonic scalers typically utilize either magnetostrictive or piezoelectric systems to create vibration. Magnetostrictive scalers utilize a stack of metal plates bonded to the tool tip. The stack is induced to vibrate by an external coil connected to an AC source. Many ultrasonic scalers also include a liquid output or lavage, which aids in cooling the tool during use. The lavage can also be used to deliver antimicrobial agents. There is some debate over whether there is an advantage to sonic or ultrasonic scaling over hand scaling and some issues arise from powered scalers. However, powered scalers tend to create aerosols, which can spread pathogens.