Time-dependent changes in dental and alveolar tissues in kidney disease

This study aimed to investigate the impact of chronic kidney disease on mineralization in dental and associated hard tissues and to characterize its time-dependent progression using micro-computed tomography and histological analyses. Six groups were established in a rat model, including three control and three CKD groups sacrificed at 1, 20, and 40 days after disease induction. CKD was induced by oral administration of adenine (80 mg/kg in 1% carboxymethyl cellulose) for 28 days, while controls received vehicle only. Mandibular bone blocks containing molars were analyzed by micro-computed tomography to evaluate dentin and alveolar bone density. Histological analysis was performed to assess pulp morphology, and immunohistochemistry was used to evaluate osteopontin (OPN), bone sialoprotein (BSP), dentin matrix protein-1 (DMP-1), and type I collagen (COL-I). Bone mineral density showed no significant effects. Dentin mineral density showed no overall disease effect, but significant effects of time and disease × time interaction, indicating different temporal patterns in control and CKD groups. Histological analysis demonstrated a progressive reduction in pulp diameter over time in the CKD groups. Immunohistochemical analyses demonstrated overall disease-associated increases in OPN, BSP, DMP-1, and COL-I expression, although the temporal and compartment-specific patterns varied among markers. These findings suggest that CKD is associated with biological alterations in dental and alveolar tissues, accompanied by increased expression of mineralization-related proteins. Although alveolar bone mineral density remained unchanged, dentin mineral density exhibited a time-dependent pattern that differed between control and CKD groups. Systemic diseases, particularly CKD, may affect oral tissues by altering the structural and biological properties of the pulp, dentin, and alveolar bone. The present findings provide experimental evidence of CKD-associated alterations in dental tissues and may help guide future translational and clinical studies investigating their potential implications for dental treatment.