Clinical study on the effect of professional cleaning of occlusal tooth surfaces on laser fluorescence measurements.

Manufacturer's advice is to professionally clean teeth before using a laser fluorescence (LF) device in order to avoid false-positive diagnoses. Professional cleaning is not included in routine dental check-ups in children in Finland because it is time-consuming. The aim of our present study was to evaluate the effect of professional cleaning of teeth on LF in children. A total of 642 occlusal surfaces in permanent molars and premolars in 9- to 16-year-olds (n = 46) were first examined visually. After that the first measurements with LF were made without cleaning the teeth. At the same appointment the second measurements were carried out after professional cleaning using a soft rubber cup and either polishing paste or plain water spray. The differences in LF of uncleaned and cleaned teeth were determined separately for teeth with a visual score of 0 (sound) and > 0. In premolars cleaning had no significant effect on LF. In molars, the values increased when the teeth were cleaned, the difference of the measurements being statistically significant in molars with visual score > 0 cleaned with plain water spray. For molars that were cleaned with paste, the differences were not statistically significant. Sealants did not modify the effect of cleaning. As a conclusion cleaning with a rotating instrument and water spray before LF measurements is recommended in teeth with visible plaque. Also in clean teeth, cleaning is advisable in cases where LF readings approach threshold level for operative intervention. The finding that uncleaned teeth gave lower values than cleaned teeth is opposite to what has been suggested. Copyright 2005 S. Karger AG, Basel.