Changes

==Introduction==

==Introduction==

[[File:Dental discoloration.jpg|right|200px|thumb|Tooth discolouration following trauma]]

[[File:Dental discoloration.jpg|right|200px|thumb|Tooth discolouration following trauma]]

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

The normal colour of teeth varies and depends on the shade, translucency and thickness of the [[Tooth - Anatomy & Physiology#Enamel|enamel]].  

Teeth can discolour following trauma to the tooth. It can be any colour from pink to black, resulting from the haemoglobin breakdown products settling in the dentinal tubules. Studies show that 92% of discoloured teeth have irreversible pulpitis. The pulp may then get secondary infected by anachoresis.  

Teeth can discolour following trauma to the tooth. It can be any colour from pink to black, resulting from the haemoglobin breakdown products settling in the dentinal tubules. Studies show that 92% of discoloured teeth have irreversible pulpitis. The pulp may then get secondary infected by anachoresis.  

There are two basic kinds of discolouration:

There are two basic kinds of discolouration:

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

:'''Intrinsic staining''': secondary to endogenous factors discolouring the underlying [[Tooth - Anatomy & Physiology#Dentine|dentine]]

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

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

'''Medications''': most commonly tetracyclines given prior to development of the permanent teeth.

'''Medications''': most commonly tetracyclines given prior to development of the permanent teeth.

'''Metal''': wear from chewing on cages or from removed endodontic bands or wires

'''Metal''': wear from chewing on cages or from removed orthodontic bands or wires

===Intrinsic Staining===

===Intrinsic Staining===

'''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.  

'''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. The teeth may appear pinkish in colour due to the visible pulp through the poor quality enamel.

 

'''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.

===Internal Resorption===

===Internal Resorption===

'''Pulpal injury''' causes vascular changes with increased oxygen tension and a decreased pH, resulting in destruction of the tooth from within the pulp from dentinoclasts.

'''Pulpal injury''' causes vascular changes with increased oxygen tension and a decreased pH, resulting in destruction of the tooth from within the pulp from odontoclasts.

The tooth has a pinkish hue.

The tooth has a pinkish hue.

===External Resorption===

===External Resorption===

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

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

===Medications===

===Medications===

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.

'''Radiographs''' should be performed to assess the viability of the tooth.

'''Radiographs''' should be performed to assess the secondary complications from pulp necrosis of the tooth.

==Treatment==

==Treatment==

For '''extrinsic staining''', internal or external bleaching can be performed, or veneers or crowns can be placed on the tooth.

For '''extrinsic staining''', veneers or crowns can be placed on the tooth.

For '''intrinsic staining''', endodontic treatment is often the treatment of choice.

For '''intrinsic staining''', endodontic treatment is often the treatment of choice if the pulp is nonvital.

Restorative procedures such as crowns or veneers will protect both the tooth and the pulp.

Restorative procedures such as crowns or veneers will protect both the tooth and the pulp.

{{Learning

{{Learning

|flashcards = [[Veterinary Dentistry Q&A 04]]

|flashcards = [[Veterinary Dentistry Q&A 04]]

}}

}}