Effects of Preventive Scaling and Ultrasonic use on Dental Restorations

Many patients receive preventive dental hygiene procedures twice a year and periodontal maintenance procedures up to four times per year. The instrumentation technique and products selected by the dental hygienist can be beneficial or detrimental to the patient’s dental restorations. Therefore, it is imperative to identify the restorative materials that are present before starting treatment. Restorations can be identified through reviewing radiographs, tactile detection and applying air to the surface of the restoration. Often times, a black line of metal may be apparent when an explorer is used on the restoration. Esthetic restorations may also reveal a dry, chalky appearance when air is applied.¹

Preventive and maintenance procedures are often performed using a combination of hand and ultrasonic instrumentation, which is usually followed by polishing. It is important to use the combination that will be most effective for deposit removal, while causing the least amount of damage to restoration and tooth structure. There is conflicting evidence regarding the effect of scaling with hand instruments versus ultrasonic instrumentation and the amount of tooth structure that is lost in each case. Some studies report that scaling with hand instruments produces greater loss of tooth structure.^2,23,24 However, other studies indicate that there is not a significant difference in the amount of tooth structure lost when comparing hand and ultrasonic instrumentation.^25,26 A recent systematic review indicated that both manual and ultrasonic instrumentation helped improve clinical outcomes.³⁸

Instrumentation with ultrasonic scalers and hand instruments has the potential to damage composite restorations (hybrid and microfilled), glass ionomers, laminate veneers and titanium implant abutments. When using ultrasonic instrumentation, the clinician should always establish proper water flow to prevent overheating, use the appropriate power level that is needed for deposit removal, and maintain correct adaptation of the side of the tip.²¹ Generally, the water flow should be increased as the power setting is increased for more tenacious deposits. Ultrasonics have the potential to alter the margins of amalgam restorations and fracture porcelain. In order to avoid damaging the restoration, the tips of scalers should never be directed into the junction where the enamel and restorative material meet.³ Make sure not to direct the tip perpendicularly to the restoration or margin, but keep the lower third of the tip parallel with the long axis of the tooth (or surface being instrumented).