EQUINE | Abstracts
A histological and ultrastructural study of equine
peripheral caries
D. Borkent, S. Smith, P. M. Dixon
Background Main limitations
Objectives Conclusion
Peripheral caries (PC) has recently been shown to
affect over half of UK and Australian horses.
To examine affected cheek teeth histologically and
ultrastructurally, to assess the possible route(s) of
carious infection into the dental tissues and to further
describe the pathological changes in affected teeth.
Study design
No dental histories were available; all teeth were
examined on a single occasion.
Equine PC causes different patterns of cemental lesions
that appear dependent on the route of cariogenic
bacterial invasion. Progression of caries can lead
to pulpitis and tooth loss. Gross examination can
underestimate the true extent of caries.
Descriptive pathological study.
Methods
Four control and 16 cheek teeth with different grades
of PC were examined grossly, histologically and by
electron microscopy.
Results
Cariogenic bacteria from plaque entered peripheral
cementum perpendicular to the sides of teeth
alongside Sharpey’s fibres or vascular channels
or more horizontally alongside exposed intrinsic
fibres and cemental growth lines. Subsequent intra‐
cemental bacterial spread created different patterns
of caries including vertical and horizontal flake‐
like patterns; deep, large flask‐shaped or smaller
superficial ellipsoid‐shaped lytic lesions. Cemental
caries progressed to affect enamel, dentine and even
pulp. Gross examination underestimated the degree of
caries observed on histological evaluation.
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• Equine Health Update •