1. Regressive and Traumatic Alterations of Teeth Unit 4

2. Regressive Alteration Attrition Abrasion Erosion

3. Attrition Physiologic wearing away Incisal, occlusal and interproximal surfaces Part of aging process Bruxism – pathologic attrition

5. Attrition – Radiologic Features Change in normal outline Flat occlusal plane Loss of mamelon Pulp chamber, canal size Hypercementosis

6. Attrition

9. Abrasion Non-physiologic wearing away Habits Toothbrush trauma Dental floss injury Occupational hazards

10. Abrasion – Radiologic Features Radiolucent defects at the cervical region Well-defined semilunar defects Pulp chambers sclerosed In case of dental floss injury, distal surfaces more involved

11. You will write cases today Describe –Type of film(s) –Location / number of lesions (problem) –Size –Shape –Border –Content –Effects on neighboring structures

12. Case 1 for write-up

13. March 2000May 2003

14. Erosion Chemical cause No bacteria involved Diet Regurgitation Occupational hazards

15. Erosion - Radiologic Features Radiolucent defects Dietary acids – labial surface Regurgitation – mandibular lingual surface Occupational – all surfaces

18. Resorption Phenomenon External Internal

19. External Resorption Periapical pathology Trauma Mechanical forces Tumors and cysts Impacted teeth Osteosclerosis Idiopathic

20. Ext. Resorption: Periapical Path

21. Ext. Resorption: Trauma

22. Case for Brett Moore

23. Ext. Resorption: Orthodontic

25. Ext. Resorption: Tumors/cysts

28. Ext. Resorption:

30. Ext. Resorption: Impacted Tooth

32. Ext. Resorption: Osteosclerosis

33. Ext. Resorption: Idiopathic

35. Case for Ruth Atterberg

36. Internal Resorption Trauma Idiopathic

37. Int. Resorption: Idiopathic

38. Internal Resorption: Trauma

40. Traumatic Injury to Teeth Concussion Luxation Avulsion

41. Concussion No displacement or loosening Crushing injury to adjoining areas Early radiographic changes may be minimal Widened PDL spaces: few days to weeks Long term effects: pulpal sclerosis, necrosis, periapical lesions

42. Luxation Dislocation of teeth: intrusion, extrusion, lateral, lingual or buccal Early radiographic observation: widened PDL spaces Long term effect: pulpal sclerosis, necrosis, periapical lesion

43. Avulsion Loss of tooth Socket outline Fracture of alveolar bone Possibility of reimplantation

44. Fracture of Teeth Coronal fracture –Cusp –Pulp Root fracture –Horizontal –Vertical (Details of fracture in Unit 11)