Periodontitis affected root surfaces are hypermineralized and contaminated with cytotoxic and other biologically active substances.The instrumented surface will inervitably be coverd by a smear layer following root planing with or without flap.Smear layer is resistant to saline rinsing, but may be removed with agents such as acids (e.g.citric acid), tetracyclines, EDTA, and laser.Low pH aqueous...