Tattiana Enrich-Essvein1, Cristina Benavides-Reyes2, Pedro Álvarez-Lloret3, María Victoria Bolaños-Carmona4, Alejandro B Rodríguez-Navarro5, Santiago González-López2. 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.
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.
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.
Entities:
Keywords:
Biomechanics; Bovine dentin; Chemical composition; Demineralization; Human dentin; Remineralization
Authors: Jefferson Luis Oshiro Tanaka; Edmundo Medici Filho; José Antônio Pereira Salgado; Miguel Angel Castillo Salgado; Luiz Cesar de Moraes; Mari Eli Leonelli de Moraes; Julio Cezar de Melo Castilho Journal: Braz Oral Res Date: 2008 Oct-Dec