The longer the UIT’s exposure time on a specific area, the greater the risk of negative effects. To avoid this pitfall, clinicians must keep the UIT moving at all times. The moving strokes should overlap and be multidirectional. Patients who are not indicated for pain control should not feel sensitivity while the UIT is moved constantly over the surface if tuning and dental supplies technique are correct, and the likelihood of iatrogenic damage should also be reduced.
Tip wear may affect the performance of UITs by reducing their displacement amplitude.19 With a magnetostrictive insert, wear is evaluated by examining the stack and working ends for damage. With both piezoelectric and magnetostrictive instruments, the length of the working end is also assessed. Shortening of the working end reduces efficiency, lengthens instrumentation time, creates the need to use increased power settings, and raises the risk for tip fracture. Unfortunately, a 1 mm loss of the working end length results in 25% less efficiency. A 2 mm loss results in 50% less efficiency, at which point tip replacement is indicated.19, Efficiency guides are available from manufacturers to objectively assess tip wear.
Clinicians should use UITs that work at optimal levels and have not outlived their usefulness. A recent study found that significantly more root surface roughness was found when worn UITs were implemented vs new UITs, and the roughness change was dependent on angle of application and power setting.20 Arabaci et al20 concluded that tip wear is just as important as other factors in preventing surface roughness.
A review of the literature assessing the use of power-driven and hand-delivered instrumentation reveals similar clinical outcomes.21 Just as with hand instrumentation, clinicians may overtreat roots with ultrasonic therapy. In addition to causing iatrogenic problems with the tooth, overinstrumentation can lead to discomfort and sensitivity, as well as loss of efficiency20 during care. The manufacturer instructions for proper use of the unit should always be followed. Patients’ nonverbal and verbal cues, such as grimaces, may indicate pain.
In the future, UITs with different materials might be recommended depending on the status of the root surface. For example, Rühling et al22 found that a teflon-coated sonic tip removed less root surface than a curet or traditional UITs, and might be an alternative for periodontal maintenance patients. In the study, a curet and a conventional sonic scaler insert removed the most root surface compared to a piezoelectric tip.22 As use of the dental endoscope grows in conventional therapy, clinicians will be able to assess the factors of optimal instrumentation while analyzing the deposit removal effectiveness, and more in vivo research will be conducted.
Analysis of the risk of overinstrumentation with ultrasonic therapy is difficult but necessary. The occurrence of overinstrumentation can be prevented using the best practices recommended by researchers, manufacturers, and clinicians. By adhering to the recommendations regarding the key factors of quality ultrasonic dental equipment, clinicians can provide both effective and safe care to their patients.