Primary teeth or baby teeth are important for three reasons: They promote proper chewing and eating They provide space for the permanent teeth and guide them into the correct position They permit normal development of speech and add to an attractive appearance Primary front teeth are replaced at an early age 6-8 years. The back teeth cuspids and molars aren’t replaced until age 10-13. It is very important to maintain the health of the primary teeth. Neglected cavities can and frequently do lead to problems, which affect developing permanent teeth.