Changes

[[File:Draining sinus 2.jpg|200px|right|thumb|Draining sinus - periapical abscess complications]]

[[File:Draining sinus 2.jpg|200px|right|thumb|Draining sinus - periapical abscess complications]]

[[File:Combined endodontic and periodontic lesion.jpg|200px|right|thumb|Combined endodontic and periodontic lesion]]

[[File:Combined endodontic and periodontic lesion.jpg|200px|right|thumb|Combined endodontic and periodontic lesion]]

Trauma to a [[:Category:Teeth - Anatomy & Physiology|tooth]] (mechanical, chemical, thermal, infective) often results in [[Enamel Organ#Pulp|pulpal]] inflammation ('''pulpitis''').   

Trauma to a [[:Category:Teeth - Anatomy & Physiology|tooth]] (mechanical, chemical, thermal, infective) often results in [[Tooth - Anatomy & Physiology#Pulp|pulpal]] inflammation ('''pulpitis''').   

Depending on the type of trauma, its severity and duration, the pulpitis may be reversible, but often this is not the case and the inflammation becomes irreversible. The result of untreated '''irreversible pulpitis''' is '''pulp necrosis''', followed by the spread of inflammation to affect the apical periodontium (apical periodontitis) and the periapical bone, resulting in bone destruction around the apex of the root (periapical disease).

Depending on the type of trauma, its severity and duration, the pulpitis may be reversible, but often this is not the case and the inflammation becomes irreversible. The result of untreated '''irreversible pulpitis''' is '''pulp necrosis''', followed by the spread of inflammation to affect the apical periodontium (apical periodontitis) and the periapical bone, resulting in bone destruction around the apex of the root (periapical disease).

==Pulpal Reactions==

==Pulpal Reactions==

[[Tooth Fractures#Crown Fractures|Crown fracture]] very often involves exposure of the [[Enamel Organ#Pulp|pulp]] in the young and older animal as the pulp chamber follows the contour of the [[Enamel Organ#Crown|crown]]. As the animal gets older there is normally a reduction in the size of the pulp cavity, which is associated with continued deposition of secondary [[Enamel Organ#Dentin|dentine]]. There are conditions that accelerate the rate of deposition of secondary dentine, thus prematurely reducing the size of the pulp cavity. [[Tooth Abrasion and Attrition|Attrition and abrasion]] are two common conditions resulting in a narrow pulp cavity. Injury, orthodontic force and disease can all alter and decrease the pulp chamber and canals. In extreme cases, injury to a [[:Category:Teeth - Anatomy & Physiology|tooth]] will result in the complete obliteration of the pulp chamber and root canals. Less commonly, the obliteration is partial, with the pulp chamber retaining the size and shape it had at the time of the injury, and the root canals becoming completely obliterated. On the other hand, injuries that cause inflammation and degeneration/necrosis of the pulp also account for many abnormally large pulp cavities, as dentine production ceases when the pulp is chronically inflamed or necrotic.

[[Tooth Fractures#Crown Fractures|Crown fracture]] very often involves exposure of the [[Tooth - Anatomy & Physiology#Pulp|pulp]] in the young and older animal as the pulp chamber follows the contour of the [[Tooth - Anatomy & Physiology#Crown|crown]]. As the animal gets older there is normally a reduction in the size of the pulp cavity, which is associated with continued deposition of secondary [[Tooth - Anatomy & Physiology#Dentin|dentine]]. There are conditions that accelerate the rate of deposition of secondary dentine, thus prematurely reducing the size of the pulp cavity. [[Tooth Abrasion and Attrition|Attrition and abrasion]] are two common conditions resulting in a narrow pulp cavity. Injury, orthodontic force and disease can all alter and decrease the pulp chamber and canals. In extreme cases, injury to a [[:Category:Teeth - Anatomy & Physiology|tooth]] will result in the complete obliteration of the pulp chamber and root canals. Less commonly, the obliteration is partial, with the pulp chamber retaining the size and shape it had at the time of the injury, and the root canals becoming completely obliterated. On the other hand, injuries that cause inflammation and degeneration/necrosis of the pulp also account for many abnormally large pulp cavities, as dentine production ceases when the pulp is chronically inflamed or necrotic.

==Periapical Lesions==

==Periapical Lesions==