A histological study of peripheral dental caries of equine cheek teeth.

Peripheral caries in equine cheek teeth is a disorder that has not been satisfactorily explained or studied, especially its histopathology. This research analyzes the histological patterns observed in 21 affected teeth, revealing cemental lesions in two formats and the presence of bacteria within the cementum and associated plaque. The grading of peripheral caries, observed by gross examination, often underestimates the intensity of the disorder as compared to histological grading.

Introduction and Methodology

• The study attempts to explore peripheral caries in equine cheek teeth, a disorder which remains inadequately examined, with the main focus being on the histopathology of the disorder.
• Decalcified sections from 21 equine peripheral caries-affected cheek teeth were histologically examined.

Findings

• Two distinct patterns of cemental lesions were observed. The first was an increasing enlargement of a specific focal flask-like lesion which was causing the breakdown of the adjacent cementum.
• The second pattern discerned was a more generalized flaking-off of thin layers of under-run surface cementum.
• A layer of plaque and food material often existed on the surface of the affected cementum, also seen within the cemental defects.
• Large numbers of bacteria within the lacunae and canaliculi of the affected peripheral cementum and within associated plaque were seen in Gram-stained sections.
• In the dentinal tubules of the adjacent, normal-appearing dentin, pioneer bacteria were noticed.
• Subgingival extension of peripheral caries lesions coupled with localized periodontal destruction was seen as quite rare.

Interpretation and Conclusion

• It was found that severity of the disorder as assessed by gross examination often underestimates the actual severity when compared to histological grading.
• This implies that the complexity and impact of peripheral caries in equine cheek teeth might be much higher than it is currently perceived.