Influence of de-remineralization process on chemical, microstructural, and mechanical properties of human and bovine dentin

Tattiana Enrich-Essvein; Cristina Benavides-Reyes; Pedro Álvarez-Lloret; María Victoria Bolaños-Carmona; Alejandro B Rodríguez-Navarro; Santiago González-López

doi:10.1007/s00784-020-03371-9

Influence of de-remineralization process on chemical, microstructural, and mechanical properties of human and bovine dentin

Clin Oral Investig. 2021 Mar;25(3):841-849. doi: 10.1007/s00784-020-03371-9. Epub 2020 May 27.

Authors

Tattiana Enrich-Essvein¹, Cristina Benavides-Reyes², Pedro Álvarez-Lloret³, María Victoria Bolaños-Carmona⁴, Alejandro B Rodríguez-Navarro⁵, Santiago González-López²

Affiliations

¹ Department of Operative Dentistry, School of Dentistry, University of Granada, Campus de Cartuja, Colegio Maximo s/n, 18071, Granada, Spain. tattiana@correo.ugr.es.
² Department of Operative Dentistry, School of Dentistry, University of Granada, Campus de Cartuja, Colegio Maximo s/n, 18071, Granada, Spain.
³ Department of Geology, Faculty of Geology, University of Oviedo, Jesús Arias de Velasco s/n, 33005, Oviedo, Spain.
⁴ Department of Pediatric Dentistry, School of Dentistry, University of Granada, Campus de Cartuja, Colegio Maximo s/n, 18071, Granada, Spain.
⁵ Department of Mineralogy and Petrology, Faculty of Sciences, University of Granada, Avenida de Fuentenueva s/n, 18002, Granada, Spain.

PMID: 32462276
DOI: 10.1007/s00784-020-03371-9

Abstract

Objectives: This study compared the chemical composition, microstructural, and mechanical properties of human and bovine dentin subjected to a demineralization/remineralization process.

Materials and methods: Human and bovine incisors were sectioned to obtain 120 coronal dentin beams (6 × 1 × 1 mm³) that were randomly allocated into 4 subgroups (n = 15) according to the time of treatment (sound, pH-cycling for 3, 7, and 14 days). Three-point bending mechanical test, attenuated total reflectance-Fourier transform infrared (ATR-FTIR), thermogravimetric (TG), and X-ray diffraction (XRD) techniques were employed to characterize the dentin samples.

Results: Regarding chemical composition at the molecular level, bovine sound dentin showed significantly lower values in organic and inorganic content (collagen cross-linking, CO₃/amide I, and CO₃/PO₄; p = 0.002, p = 0.026, and p = 0.002, respectively) compared to humans. Employing XRD analyses, a higher mineral crystallinity in human dentin than in bovines at 7 and 14 days (p = 0.003 and p = 0.009, respectively) was observed. At the end of the pH-cycling, CI (ATR-FTIR) and CO₃/PO₄ ratios (ATR-FTIR) increased, while CO₃/amide I (ATR-FTIR), PO₄/amide I (ATR-FTIR), and %mineral (TG) ratios decreased. The extension by compression values increased over exposure time with significant differences between dentin types (p < 0.001, in all cases), reaching higher values in bovine dentin. However, flexural strength (MPa) did not show differences between groups. We also observed the correlation between compositional variables (i.e., PO₄/amide I, CI, and %mineral) and the extension by compression.

Conclusions: Human and bovine dentin are different in terms of microstructure, chemical composition, mechanical strength, and in their response to the demineralization/remineralization process by pH-cycling.

Clinical relevance: These dissimilarities may constitute a potential limitation when replacing human teeth with bovines in in vitro studies.

Keywords: Biomechanics; Bovine dentin; Chemical composition; Demineralization; Human dentin; Remineralization.

MeSH terms

Animals
Cattle
Dentin*
Humans
Incisor*
Minerals

Substances

Minerals

Grants and funding

CGL2015-64683-P/Research Projects of the Spanish Government