PROOF OF EFFICACY OF DIFFERENT MODIFIED SONIC SCALER INSERTS USED FORDEBRIDEMENT IN FURCATIONS - A DUMMY HEAD TRIAL

The purpose of this study was to determine the suitability of differen t scaling instruments for surgical removal of hard and soft bacterial deposits and for the removal of soft accretions only for maintenance t reatment within furcations. 12 upper and 12 lower plastic replicated m olars, with through-and-through furcations, were instrumented 3x with 4 different types of instruments: (1) hand instruments; (2) a conventi onal sonic scaler insert; (3) a set of 3 modified sonic scaler inserts with budded tips and different angulated shafts; (4) a set of 3 sonic scaler inserts with a plastic- coating and different angulated shafts . The plastic replicas were fixed in a dummy head without any replicat ed soft tissues. In the furcation area, an easily removable surface co ating material was applied to the teeth to represent the ''plaque'' an d a second, more stubborn lacquer layer representing ''calculus/cement um''. Following instrumentation, the following parameters were recorde d to assess efficacy; time required for instrumentation, loss of weigh t, depth of substance removal at the furcation entrance, % of furcatio n area instrumented, whereby removal of these 2 layers was judged sepa rately. Only minor differences were observed between hand instruments, conventional and budded sonic scaler inserts as to loss of weight, de pth of substance loss and area instrumented. The plastic-coated sonic scaler inserts were just as effective in surface layer removal represe nting ''plaque'' as the 3 other instruments, but resulted in less loss of weight and less depth of substance removal. In conclusion, the mor e aggressive hand instruments, the conventional and budded sonic scale r insert, are preferably used for the surgical phase to increased ease of entry into the furcation dome. An effective debridement of the fur cation roof seems only possible with an odontoplastic, for which a fur cation is fitted to the instrument by means of an intensive instrument ation, thus leading to weight loss and pronounced substance removal. T he plastic-coated sonic scaler inserts seems to be a reasonable choice for maintenance treatment within furcation, since this treatment phas e is usually restricted to removal of soft bacterial deposits.