Changes

==Introduction==

==Introduction==

The normal colour of teeth varies and depends on the shade, translucency and thickness of the enamel.  

The normal colour of teeth varies and depends on the shade, translucency and thickness of the [[Enamel Organ#Enamel|enamel]].  

There are two basic kinds of discolouration:

There are two basic kinds of discolouration:

:'''Intrinsic staining''': secondary to endogenous factors discolouring the underlying dentin

:'''Intrinsic staining''': secondary to endogenous factors discolouring the underlying [[Enamel Organ#Dentine|dentine]]

:'''Extrinsic staining''': from surface accumulation of exogenous pigment

:'''Extrinsic staining''': from surface accumulation of exogenous pigment

===Intrinsic Staining===

===Intrinsic Staining===

'''Hyperbilirubinaemia''': affects all teeth, occurs when dentin is being formed and bilirubin accumulates in the tooth. Lines of resolution may be seen on the teeth if the problem is solved during dentin development

'''[[Hyperbilirubinaemia]]''': affects all teeth, occurs when dentin is being formed and [[bilirubin]] accumulates in the tooth. Lines of resolution may be seen on the teeth if the problem is solved during dentin development

'''Red blood cell destruction''': following traumatic injury to the tooth. Haemoglobin breakdown in the pulp from a pulpitis, which progressed from pink to grey to black.  

'''Red blood cell destruction''': following traumatic injury to the tooth. Haemoglobin breakdown in the pulp from a pulpitis, which progresses from pink to grey to black.  

'''Amelogenesis imperfecta''': developmental alteration in the structure of the enamel, giving a chalky appearance and a pinkish colour to all teeth.  

'''Amelogenesis imperfecta''': developmental alteration in the structure of the enamel, giving a chalky appearance and a pinkish colour to all teeth.  

'''Infectious agents''': parvovirus and distemper virus especially affect the formation of enamel. There is '''enamel hypoplasia''' and the pitted areas have black edges and the dentin is brownish.

'''Infectious agents''': [[:Category:Parvoviridae|parvovirus]] and [[Canine Distemper Virus|distemper virus]] especially affect the formation of enamel. There is '''enamel hypoplasia''' and the pitted areas have black edges and the dentin is brownish.

'''Dental fluorosis''': excess fluoride consumption leads to enamel hypoplasia with black edges. The enamel is lusterless and has yellow-brown zones of discolouration.

'''Dental fluorosis''': excess fluoride consumption leads to enamel hypoplasia with black edges. The enamel is lusterless and has yellow-brown zones of discolouration.

===External Resorption===

===External Resorption===

This is caused by many conditions such as '''trauma, orthodontic treatment, periodontal disease, tumours and periapical inflammation'''. Osteoclasts resorb the tooth structure.

This is caused by many conditions such as '''trauma, orthodontic treatment, [[Periododntal Disease|periodontal disease]], tumours and periapical inflammation'''. [[Bones - Anatomy & Physiology#Cells|Osteoclasts]] resorb the tooth structure.

===Medications===

===Medications===

'''Tetracycline''': binds to calcium and forms a calcium orthophosphate complex that is laid down into the collagen matrix of the enamel.  

'''Tetracycline''': binds to [[calcium]] and forms a calcium orthophosphate complex that is laid down into the collagen matrix of the enamel.  

It results in a yellow-brown discolouration. This can only occur when the enamel is being formed.

It results in a yellow-brown discolouration. This can only occur when the enamel is being formed.

There may be a '''history of treatment''' with a particular drug or supplement, or a history of trauma.

There may be a '''history of treatment''' with a particular drug or supplement, or a history of trauma.

If the animal is '''young''' this may indicate of a developmental process.

If the animal is '''young''' this may indicate a developmental process.

Food or plaque-related discolourations should be obvious on close dental examination and probing.

Food or plaque-related discolourations should be obvious on close dental examination and probing.

Lobprise, H. (2007) '''Blackwell's Five Minute Consult Clinical Companion: Veterinary Dentistry''' ''Wiley-Blackwell''

Lobprise, H. (2007) '''Blackwell's Five Minute Consult Clinical Companion: Veterinary Dentistry''' ''Wiley-Blackwell''

[[Category:To Do - Helen]]

 

[[Category:To Do - Review]]

[[Category:Teeth - Pathology]]

[[Category:Dental Diseases - Cat]]

[[Category:Expert Review]]