Odontoblast apoptosis and intratubular mineralization of sclerotic dentin with aging. (April 2022)

• Record Type: Journal Article
• Authors: Yan, Weishi; Jiang, Edwin; Renteria, Cameron; Paranjpe, Avina; Arola, Dwayne D.; Liao, Lan; Ren, Xiuyun; Zhang, Hai
• Is Part Of: Archives of oral biology. Volume 136(2022)
• Publication Date: 2022-04
• Subjects: EDS energy-dispersive X-ray spectroscopy -- H&E hematoxylin and eosin -- SEM scanning electron microscope; Tubular sclerosis -- Ageing -- Odontoblast -- Apoptosis; Mouth -- Periodicals; Mouth -- Diseases -- Periodicals; Dentistry -- Periodicals; Electronic journals; 617.6005
• DOI: 10.1016/j.archoralbio.2022.105371
• Languages: English
• ISSNs: 0003-9969

Abstract

Abstract: Objectives: The aims of the study were to evaluate the roles of odontoblast apoptosis in the progression of tubular sclerosis of teeth from donors at different ages and assess its correlation to chemical composition and mechanical properties. Design: Healthy human teeth were obtained and divided into young (age ≤ 25, n = 12) and old (age ≥ 60, n = 12) groups. Odontoblasts were counted with standard hematoxylin and eosin staining. Odontoblast apoptosis within dentinal tubules was determined by cleaved caspase‐3 immunostaining. Teeth in each group were evaluated by dynamic nanoindentation and energy-dispersive X-ray spectroscopy (EDS). Results: The number of odontoblasts decreased significantly with age. The most prominent change occurred in the apical third of roots. Odontoblastic apoptosis was visualized within dentinal tubules. The apoptosis staining fraction was significantly higher in the outer and inner dentin of old teeth when compared with young teeth (p < 0.05). EDS showed increased calcium content in peritubular dentin but a decrease in the intertubular dentin with increasing age. Scanning based nanoindentation showed that the old intertubular dentin exhibited a significantly higher elastic modulus. Conclusions: Odontoblast apoptosis, starting at the cell extension in dentinal tubules and proceeding from outer to inner dentin, contributes to the stoichiometric Ca/P ratio in peritubular dentin, which is potentially responsible for intratubular mineralization due to an imbalance of calcium and phosphorous ions. Highlights: Odontoblasts and tubular sclerosis were analyzed for different aging groups. Odontoblasts diminish with aging and most prominent in apical third. Odontoblastic apoptosis was visualized within dentinal tubules. Stoichiometric Ca/P ratio changes with age in peritubular and intertubular dentin.