Cementum is the calcified tissue that covers the root dentin of teeth. It is classified as either acellular or cellular. Acellular cementum forms during root development and contains mineralized Sharpey's fibers. Cellular cementum lies over acellular cementum and contains cementocytes in lacunae. It is thicker in the apical root region. Cementum contains collagen types I, III, V, XII and XIV which are produced by fibroblasts and cementoblasts. It also contains non-collagenous proteins and cells. Cementum can be classified as acellular afibrillar, acellular extrinsic fiber, cellular mixed stratified or cellular intrinsic fiber depending on its