Background/aims: In a dummy-head trial, we assessed how effectively untrained operators were able to learn scaling with curettes and power-driven instruments.
Methods: Two untrained operator groups (n = 11 each) received six 2-h lessons during a 10-week period following a training program. Subgingival scaling was performed with curettes (GRA) and a power-driven system (PP). At 6 test days each subject had to instrument 10 test teeth. The percentage of debrided area was assessed with an image analysis program. Learning success was measured as a percentage of debrided root area and scaling time. Furthermore, the effectivity was related to difficulty in anatomical situations and access to root surfaces. Statistical analysis was carried out with SPSS.
Results: At baseline, effectivity was 63.1% (GRA) vs. 52.3% (PP). Between weeks 9 and 11, operators reached a plateau for group GRA at 84.7% and group PP at 81.3%. Scaling time did not differ between the two groups. Debridement of teeth with complex root shapes that were hard to access was less effective with the power-driven system.
Conclusion: Independent of the instrument used, untrained operators were only able to debride root surfaces at low levels of efficacy. With systematical training, effective scaling with the power- driven system was as easy to learn as with hand instruments. On root surfaces with complicated shape and anatomy or difficult accessibility, the power-driven system works significantly less effectively.