July 2007
Dr Gerhard Steenkamp

A 5-year-old Cocker Spaniel is presented for a routine scale and polish procedure.  The dog is in good health and there is no history of inappetence.  While doing a thorough oral inspection under general anaesthesia, you see the following pathology.
 

a) Which tooth/teeth are involved?
b) Give 3 differential diagnoses for this pathology.
c) What is the pathogenesis of caries in dogs?
d) What treatment options are available for carious teeth?

Memo

a) The right maxillary 1st (109) and 2nd (110) molars.

b) Caries (tooth decay), Resorptive lesions, Crown fractures.

c) The pathogenesis of caries is complex.  Cariogenic bacteria, that is bacteria that metabolises refined carbohydrates and produce weak organic acids with a resultant decrease in the localised pH.  These bacteria usually colonises pits and fissures of the flat occlusal surfaces (molars).  When the saliva is unable to buffer the lowered localised pH, demineralisation of the adjacent enamel and dentin occurs resulting in cavitation.  This process continuous until the pulp is finally exposed and pulpitis develops.  If the pulpitis is left untreated it will progress to pulp necrosis

d) When caries are restricted to the enamel only or very shallow in the dentin, a restoration of the tooth is indicated.

As soon as the caries are very deep, or the pulp is exposed, an endodontic procedure (root canal therapy) is indicated to treat the inflamed pulp. Thereafter a restoration should be placed.

In cases as depicted on the photo, there is marked crown destruction as well as pulp exposure and extraction of the tooth is the only treatment available.

Caries is a preventable chronic disease by brushing teeth regularly and reducing the intake of refined carbohydrates