Endodontics
Course Review
Enoch Ng, DDS 2014
External Root Resorption
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Pathologic process initiated in periodontium, initially affecting external tooth surfaces
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Clastic cells from the periodontium
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Radiographic features
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Irregular radiolucent enlargement of canal
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Root canal space can be followed through resorptive defect
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Defect moves on off angled radiographs
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External Surface Resorption
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Physiologic process causing small superficial defects in cementum and underlying dentin, which are
repaired by deposition of new cementum
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Localized inflammatory response/localized area of resorption/repair
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Transient (2-3 weeks long)
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Self-limiting
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Occurs in >90% of teeth
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Small, generally not radiographically visible
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No treatment
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External Replacement Resorption
Ankylosis – clinical diagnosis of end result of replacement resorption where tooth is no longer
capable of normal physiologic movement from fusion of bone to root surface
Dull sound from percussion
Change in incisal edge as patients grow/develop
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Pathologic loss of cementum, dentin, PDL, with subsequent replacement of such structures by bone,
causing fusion of bone and tooth – a “mistake” vs a disease process
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Frequent complication of avulsions and luxation injuries
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Loss of PDL and cementum layer leads to replacement of tooth structure with bone
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Diagnosis
Radiographic loss of PDL, bone replacing tooth structure
Lack of physiologic mobility
Metallic sound upon percussion
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Treatment
No predictable treatment
Slow progression
Goal is prevention
