Objective: Previous studies have shown that endotoxins are located on the periodontally diseased root cementum and not within it. To what extent a Teflon-tubed sonic scaler was capable of removing bacterial deposits in comparison to conventional scaling instruments, and the resulting root surface roughness and root surface topography, were recently assessed. The objective of the present study was to evaluate how much root cementum is removed with these instruments. Methods and Materials: Eighty-two teeth were treated subgingivally on one approximal site either with a Teflon-coated sonic scaler insert (tSS), a Gracey curette, a conventional sonic scaler (SS), a piezoelectric ultrasonic scaler insert (US), or an oscillating Periotor insert (PT) before extraction. The untreated site served as control. The width and length of cementum removal were compared histomorphometrically. Nonparametric analyses were carried out for statistical comparison. Results: The US, PT, and tSS inserts removed less substance than the curettes or SS inserts. The cementum removed was 40 µm for root surfaces treated with the curette or SS, 30 µm for those treated with US, 20 µm for PT, and 17 µm for tSS. Conclusion: The Teflon-coated sonic scaler inserts can be a reasonable choice for gentle maintenance treatment of compliant patients with good plaque control, and little or no subgingival deposits. Schlagwörter: curette, debridement, subgingival polishing, substance removal, sonic instrument, ultrasonic