A histological and ultrastructural study of equine peripheral caries.
Authors: Borkent D, Smith S, Dixon P M
Journal: Equine veterinary journal
Summary
# Peripheral Caries in Equine Cheek Teeth: Histological Insights into Bacterial Invasion Pathways and Lesion Progression Affecting over half of UK and Australian horses, peripheral caries (PC) represents a significant but poorly understood pathological condition; this 2020 study by Borkent, Smith and Dixon examined 16 affected cheek teeth alongside four controls using histological and electron microscopy techniques to map how cariogenic bacteria invade dental tissues and characterise the resulting lesion patterns. The researchers identified multiple bacterial entry routes into peripheral cementum—perpendicular invasion alongside Sharpey's fibres and vascular channels, as well as more horizontal spread along exposed intrinsic fibres and cemental growth lines—each producing distinct carious patterns ranging from vertical and horizontal flake-like lesions to deep flask-shaped or smaller superficial ellipsoid cavitations. Critically, cementum-bound infection progressed into enamel, dentine and occasionally pulp tissue, yet gross oral examination substantially underestimated the true extent of caries visible histologically. For practitioners, this work emphasises that early-stage PC may be more extensive than visual inspection suggests, reinforcing the need for thorough probing and potentially advanced imaging when PC is suspected; understanding the variable lesion morphologies and invasion pathways informs surgical approach planning, whilst the documented progression to pulpitis underscores the importance of timely intervention to prevent tooth loss.
Read the full abstract on PubMed
Practical Takeaways
- •Peripheral caries is highly prevalent and may be underdiagnosed on routine oral examination; detailed histological assessment is needed to determine true disease extent
- •Progressive cemental caries can lead to severe complications including pulp involvement and tooth loss, emphasizing need for early detection strategies
- •Understanding bacterial invasion routes through cemental structures may inform preventive strategies targeting plaque management and cemental integrity in affected horses
Key Findings
- •Cariogenic bacteria invade peripheral cementum via Sharpey's fibres, vascular channels, and along cemental growth lines, creating varied lesion patterns
- •Cemental caries progresses to affect enamel, dentine, and pulp, potentially leading to tooth loss
- •Gross examination significantly underestimates the extent of caries compared to histological evaluation
- •Peripheral caries affects over 50% of UK and Australian horses, representing a significant equine dental disease