Substance loss caused by scaling with different sonic scaler inserts--an in vitro study

BACKGROUND, AIMS: Depending on the phase of periodontal treatment, power-driven inserts with different power levels are necessary: during initial treatment and flap operations, it must be possible to remove calculus which firmly adheres to the root surface with great efficiency; in contrast, gentle root-surface instrumentation has a high priority during maintenance treatment. Recently, modified sonic scaler inserts have been introduced: diamond-coated inserts for open flap operations and slim probe-shaped sonic scaler inserts for deplaqueing during maintenance. METHOD: We compared the substance removal by these inserts to that of a conventional insert. In a bench system which allows application force, stroke height, and width and frequency of instrumentation to be monitored and also permits assessment of the topography before and after instrumentation (yielding depth removal and removed volume), we instrumented aluminum rods in triplicate and bovine roots in a 5-fold repetition. RESULTS: With high application forces (1.0 N), the diamond-coated inserts removed 30 to 50% more substance than the conventional one. Except for the slim inserts, there was a significant linear relationship between increasing force and removed volume. Probe-shaped inserts do not remove considerable substance even with increasing pressures. CONCLUSIONS: Diamond-coated inserts remove tooth substance very effectively and must thus be handled with care: more pressure effects more removal. Probe-shaped inserts can be used without risk during maintenance visits.