Gross, computed tomographic and histological findings in mandibular cheek teeth extracted from horses with clinical signs of pulpitis due to apical infection.

The research investigates the pathological changes in horse teeth suffering from a specific type of dental pulpitis where the tooth’s apex is infected, with no associated coronal fractures or periodontal disease. The study uses computed tomography (CT) scans along with gross observation and histopathological examination to understand these changes and how they present in this condition.

Methodology

• The study used a descriptive method with diseased teeth and healthy teeth for comparison.
• The diseased teeth were extracted from horses showing clinical signs of pulpitis, while the control group comprised teeth from cadavers with no history of dental disease.
• The extracted teeth were subjected to CT scans in the transverse plane at 1 mm intervals.
• Once scanned, the teeth were sectioned transversely, photographed, and prepared for histopathological examination.
• The tomographic images were then compared with the corresponding gross and histological sections of the teeth.

Results

• The CT scans showed that cement, dentine, and bone had similar attenuation ranges (550-2000 Hounsfield Units, HU), but they could be differentiated from pulp (-400 to 500 HU) and enamel (> 2500 HU).
• From the gross examination, twelve different dental lesions were identified, ten of which were characterised when histologically examined.
• Previously unseen conditions such as reactive and reparative dentinogenesis and extensive pulpar mineralisation were identified.
• Pulpar oedema, neutrophilic inflammation, cement and enamel defects, and reactive cemental deposition were similarly observed.
• Mineralised tissue deposition, defects in mineralised tissue, and the presence of food material in the pulpar region corresponded well between CT and pathological findings.
• However, pulpar and dentinal necrosis and cement destruction visible in the gross and histological examinations didn’t correspond to any changes seen in the CT scans.

Conclusions

• Computed tomography is useful for identifying deposition and defects of mineralised material, but it is less effective at identifying inflammation and tissue destruction.
• Furthermore, the study concludes that the equine dentine-pulp complex reacts to infection or damage by undergoing reactive and reparative changes.

This research contributes to the developing understanding of the pathogenesis of equine dental pulpitis – a common condition causing extensive pain in horses.