Fig. 7From: Influence of scaler tip design on root surface roughness, tooth substance loss and patients’ pain perception: an in vitro and a randomised clinical trialScanning electron micrograph showing a cross-section of the tooth before scaling at × 50 magnification. Two reference points shown: upper reference point (UR) and lower reference point (LR). Tooth thickness (D) is measured from the outer tooth surface (T) (dotted lines) to the reference points, UR and LR. c is cementum, d is dentine and p is pulpBack to article page