Structural and chemical heterogeneity of pulp stones in young untreated bovine incisors: frequent dentin-like mineralizations.

Pulp stone research has predominantly relied on aged or clinically treated human teeth, limiting insights into early-stage mineralization processes. This study investigates young bovine incisors (3-4 years old, ≤2 years after eruption) as models for characterizing the prevalence, morphological, and material characteristics of ectopic mineralized deposits frequently found within the dentin-pulp complex. A total of 100 incisors, selected from a pool of 1000 teeth extracted from 250 lower cattle jaws (Bos Taurus Taurus), were screened using cone-beam computed tomography (CBCT). Teeth exhibiting radiopaque deposits within the pulp space were further analyzed by high-resolution micro-computed tomography (μCT). A subset of specimens underwent complementary multimodal characterization, including laminography, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), micro-X-ray fluorescence (μ-XRF), and X-ray diffraction (XRD). Adjacent healthy dentin served as a reference. Mineralized deposits were identified in the pulp spaces of 30 % of the seemingly normal teeth, appearing as free-standing structures or, more frequently, larger deposits attached to canal walls. μCT demonstrated substantial variability in size and spatial distribution, with volumes ranging from <0.01 mm3 to >5 mm3. SEM and X-ray imaging revealed heterogeneous internal architectures, including layered and channel-like features. μ-XRF analysis identified localized zinc enrichment, while XRD indicated hydroxyapatite as the dominant crystalline phase, with lattice parameters comparable to adjacent dentin. These findings highlight the morphological heterogeneity of mineralizations in young bovine teeth, though the present study does not directly reveal causative mechanisms. Given the absence of age-related and pathological confounders, bovine incisors represent a useful experimental model for investigating early-stage, partially controlled biomineralization of the extracellular matrix in the pulp of healthy normal teeth.