What is the life of magnetostrictive inserts and piezoelectric tips? How often should they be replaced and how do you know when it’s time?
The life of inserts or tips depends on how many are available for use, the number used per procedure, patient load, calculus type/tenacity, and sterilization processes. A calculator that estimates insert/tip cost by procedure and usage per year is available online.1
To assess the condition of an insert/tip, the shape and length should be evaluated. Misshapen or bent tips might result in reduced vibration, inadequate water flow, and patient discomfort. Loss of length in the tip can cause reduced efficiency.2 With a 1-mm and 2-mm reduction in length, tips experienced a decrease in vibration, which could affect instrumentation performance.2 To compensate, clinicians might increase pressure and power, which is not advised.3
The simplest way to evaluate the shape and length of inserts/tips is to use the manufacturer’s wear/efficiency guide. If the shape of the tip does not match the silhouette of the shape on the guide, replace the insert. Also, match the tip to the appropriate outline to measure length. Generally, it is time to reorder when the insert/tip is operating at 25% efficiency (ie, loss of 1 mm of active tip). At 50% efficiency (ie, loss of 2 mm of the active tip) the insert/tip should be replaced. Another option for assessing tip shape and length is to compare the used insert/tip to a new one. Make sure to compare old and new inserts/tips of the same design and manufacturer.
Three additional parts of magnetostrictive inserts are important to asses: the stack, o-rings, and external water port. The layers of the stack should lay next to one another and not be splayed, fractured, bent, or detached. Any of these conditions might result in inadequate power or no vibration. Inserts with compromised stacks need replacement. It is best to handle the insert by the grip to prevent any undue pressure on the stack. Use of cassettes during cleaning and sterilization should protect the insert.
O-rings might become dry, brittle, or cracked, causing water to leak at the handpiece and insert junction. Additionally, the insert may not seem secure in the handpiece. To lubricate the o-rings use water; oil-based products, such as petroleum jelly, can cause drying or cracking and may get into the water channel.4 You can change the o-ring to extend the insert’s life. Use dressing pliers to pull the o-ring over the stack, then slide a wide drink straw over the stack.4 Apply the new o-ring to the bottom of the straw and roll it into the o-ring slot.4 Also, a bent water port could compromise the water irrigation, interfering with correct tuning and performance. The insert might need to be replaced if water cannot be delivered correctly.
Piezoelectric tips do not have a stack, o-ring, or external water delivery. However, they have wrenches to protect the tip and the clinician, and the tips should stay securely in the wrenches. Worn or cracked wrenches need to be replaced. If a piezoelectric tip does not stay in the handpiece, the “flats” on the base of the tip might be worn and replacement is indicated.
In conclusion, always examine inserts/tips in patient set-ups before use to quickly evaluate the shape, length, and condition. Check your inserts/tips routinely for a more in-depth assessment. Some clinicians use a coding system to identify inserts/tips that are worn (1 mm tip loss) and will soon need replacing. Use manufacturer’s guides to aid in decision making. Correct instrument processing should not affect the lifespan of inserts/tips. Check the manufacturer’s instructions for proper cleaning and sterilization.
- Hu-Friedy. Calculate Your Magneto Insert/Piezo Tip Cost Per Use. Available at: hu-friedy.com/cost-calculator. Accessed January 29, 2020.
- Lea SC, Landini G. Walmsley AD. 2006. The effect of wear on ultrasonic scaler tip displacement amplitude. J Clin Periodontol. 2006;33;1:37–41.
- Arabaci T, Cicek Y, Dilsiz A, Erdogan Y, Kose O, Kizildag A. Influence of tip wear of piezoelectric ultrasonic scalers on rot surface roughness at different working parameters. A profilometric and atomic force microscopy study. Int J Dent Hyg. 2013;11:69–74.
- Hu-Friedy. Magneto Inserts and Piezo Tips Performance Assessment Guide. Available at: hu-friedy.com/sites/default/files/2018-10/828_Magneto%20Piezo_Assessment_Guide_0518_v9.pdf. Accessed January 29, 2020.
From Dimensions of Dental Hygiene. February 2020;18(2):46.