The anatomical crown of the tooth is covered by enamel and root is covered by cementum. The dentin forms the major part of the tooth. The dentin structure is very similar to that of the bone both physically and chemically which is why many scientists have wondered about using its properties for developing a novel bone graft material. In contrast with hard and brittle enamel dentin is viscoelastic. The organic structure of dentin which is about 35% is composed of mainly type I collagen embedded in mucopolysaccharides ground substance. Approximately half of the non-collagenous composition consists of hyperphosphorylated proteins. The acidic glycoproteins, Gla-proteins, serum proteins, proteoglycans etc. composes the remaining part. The dentin matrix consists of many similar proteins as that of bone like dentin phosphoprotein, dentin sialoprotein etc.. The matrix also consists of many growth factors. Any external disturbance like an infection, trauma, calcium or phosphorous metabolic changes can lead to defective amelogenesis. Mutational changes can lead to defect in dentin. An early diagnosis can result in a satisfactory treatment plan contributing to functional and esthetical compensation.