1. Ahmed Abdulelah Abduljawad Al-jawady College of dentistry Mosul-Iraq

2. What is the difference? Scaling: removal of deposits around tooth surface without removal of tooth structure. Root planning: removal of subgingival plaque,calculus and infected cementum to produce a smooth, hard and clean surface. 3. Healing following scaling and root planing: Reduction in pocket depth occurs by two principal mechanisms: 1- Recession of the gingival margin due to resolution of inflammation and subsequent reduction in swelling and hyperplasia 2- Reattachment to the root surface. This occurs primarily by the formation of a long junctional epithelial attachment. Epithelial cells grow from the gingival sulcus to repopulate the pocket lining and attach by hemidesmosomes to the root surface. This is most likely to occur in the absence of inflammation. Whilst the periodontal ligament contains precursor cells that have the ability to form a connective tissue reattachment. 4. Scaling and Curettage Instruments 1- Sickle Scalers. Sickle scalers have a flat surface and two cutting edges that converge in a sharply pointed tip. The sickle scaler is used primarily to remove supragingival calculus. Because of the design of this instrument, it is difficult to insert a large sickle blade under the gingiva without damaging the surrounding gingival tissues 5. 2- Curettes. The curette is the instrument of choice for removing deep subgingival calculus, root planing altered cementum, and removing the soft tissue lining the periodontal pocket . 6. Double-ended Gracey curettes are paired in the following manner: Gracey #1-2 and 3-4: Anterior teeth Gracey #5-6: Anterior teeth and premolars Gracey #7-8 and 9-10: Posterior teeth: facial and lingual Gracey #11-12: Posterior teeth: mesial Gracey #13-14: Posterior teeth: distal 7. Technique: