Difference between primary and permanent.ppt
- 1. Primary vs Permanent Teeth Prof. Dr. Deepthi K Dept of Oral and Maxillofacial Pathology
- 2. Primary • Lighter in colour: bluish white –milky white (MILK TEETH) • 6 months to 5-6 years • 20 teeth • Smaller in dimension Permanent • Darker in colour, grayish or yellowish white • 6 years onwards • 32 teeth • Larger in dimension
- 4. Primary Permanent • First molar is smaller in dimension than second molar • Mamelons absent • More supplemental grooves • Contact areas are broader ,flatter and gingival • First molar is larger in dimension than second molar • Mamelons are present on newly erupted teeth • Less supplemental grooves • Contact points are more occlusally placed
- 7. Primary Permanent wider mesiodistally wider cervico incisally
- 8. Primary • Cervical ridges are prominent especially on buccal aspect • Narrow occlusal tables • Sharp cervical constriction Permanent • Cervical ridges are less prominent • Less convergence of buccal and lingual surfaces hence wider occlusal table • Less constriction of the neck
- 10. Enamel Primary • Thinner and uniformly thick(1mm) • Less number of striae • Less mineralized Permanent • About 2-3 mm thick • More number of striae • Highly mineralized
- 11. Primary Enamel rods at the cervical slopes occlusally from DEJ Permanent Enamel rods are oriented gingivally
- 12. Primary • DEJ is less scalloped • Neonatal lines present in all primary teeth Permanent • More scalloped • Present only in first molars
- 13. Dentin Primary • Less mineralized • Dentin is less dense so It cuts more easily • Dentinal tubules are less regular • Reparative dentin formation is more extensive and irregular Permanent • Highly mineralized • Dentin is difficult to cut as it is more dense • Dentinal tubules are more regular • Reparative dentin formation is less
- 15. Root Primary • The roots are larger and slender compared to crown size • Root trunk is smaller • Roots flare outward to accommodate permanent teeth • Physiologic resorption during shedding Permanent • Roots are more bulbous and shorter in comparison to crown • Root trunk is larger • Marked flaring is absent • Physiologic resorption is absent
- 19. Pulp Primary • Pulp chamber is larger in relation to crown size • Pulp horns are more prominent and are closer to the outer surface • High degree of cellularity and vascularity in tissue Permanent • smaller in relation to crown size • comparatively away from the outer surface • Comparatively less degree of cellularity and vascularity
- 21. Pulp Primary • High potential for repair • Root canals are ribbon like. Radicular pulp is thin, tortuous and branch • Accessory canals are present in good number • Density of innervation is less of which primary teeth are less sensitive Permanent • Less potential for repair • Root canals are well defined with less branching • Floor of pulp chamber does not have any accessory canals • Density of innervation is more
- 22. Accessory canals
- 23. Pulp Primary • Enlarged apical foramen, abundant blood supply, demonstrates an inflammatory response • Localisation of infection and inflammation is poorer in pulp Permanent • Foramens are restricted Reduced blood supply favours calcific response • Inflammation and infection in pulp is localised
- 25. Periodontium Primary • Cementum is very thin • Secondary cementum is absent • Majority of CEJs are knife edge • Alveolar atrophy is rare • Gingivitis is generally absent in a healthy child Permanent • Thick • Present • Majority of CEJs are over lapping type • Alveolar atrophy occurs • Gingivitis is common in adults