Comparison of collagen features of distinct types of caries-affected dentin

• Published in: Journal of dentistry Vol. 127; p. 104310
• Main Authors: Matos, Adriana Bona, Reis, Mariana, Alania, Yvette, Wu, Christine D., Li, Wei, Bedran-Russo, Ana K.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.12.2022; Elsevier Limited
• Subjects: Adhesives; Amides - analysis; Anaerobic conditions; Biodegradability; Biodegradation; Biofilms; Birefringence; Caries-affected dentin; Chemical analysis; Chemical composition; Collagen; Collagen - analysis; Conformation; Damping capacity; Demineralizing; Dental caries; Dental Caries - pathology; Dental Caries Susceptibility; Dentin; Dentin - chemistry; Dentin-Bonding Agents - chemistry; Dentistry; Dynamic mechanical analysis; Enamel; Extracellular matrix; Humans; Mechanical properties; Microbiological model; Microscopy; Molars; Pentosidine; Phosphates; Picrosirius red staining; Post-translation; Proteins; Quality assessment; Raman spectroscopy; S. mutans; Spectrum analysis; Streptococcus infections; Substrates; Sucrose; Viscoelasticity; United States > US; Germany; Microbiological model; Collagen; S. mutans; Caries-affected dentin; Picrosirius red staining; Raman spectroscopy; Dynamic mechanical analysis
• ISSN: 0300-5712; 1879-176X
• DOI: 10.1016/j.jdent.2022.104310

To compare the biodegradability, mechanical behavior, and physicochemical features of the collagen-rich extracellular matrix (ECM) of artificial caries-affected dentin (ACAD), natural caries-affected dentin (NCAD) and sound dentin (SD). Dentin specimens from human molars were prepared and assigned into groups according to the type of dentin: ACAD, NCAD, or SD. ACAD was produced by incubation of demineralized SD with Streptococcus mutans in a chemically defined medium (CDM) with 1% sucrose for 7 days at 37 °C under anaerobic conditions. Specimens were assessed to determine collagen birefringence, biodegradability, mechanical behavior, and chemical composition. Data were individually processed and analyzed by ANOVA and post-hoc tests (α = 0.05). CDM-based biofilm challenge reduced loss, storage, and complex moduli in ACAD (p < 0.001), while the damping capacity remained unaffected (p = 0.066). Higher red and lower green birefringence were found in ACAD and NCAD when compared with SD (p < 0.001). Differently to ACAD, SD and NCAD presented higher biodegradability to exogenous proteases (p = 0.02). Chemical analysis of the integrated areas of characteristic bands that assess mineral quality (carbonate/phosphate and crystallinity index), mineral to matrix (phosphate/amide I) and post-translational modifications (amide III/CH2, pentosidine/CH2, and pentosidine/amide III) (p<0.05) showed that NCAD was significantly different from SD while ACAD exhibited intermediate values. CDM-based biofilm challenge produced a dentin ECM with decreased mechanical properties and increased collagen maturity. The compositional and structural conformation of the ACAD suggested that CDM-based biofilm challenge showed potential to produce artificial lesions by revealing a transitional condition towards mimicking critical features of NCAD. This study highlights the importance of developing a tissue that mimics the features of natural caries-affected dentin ECM for in vitro studies. Our findings suggested the potential of a modified biofilm challenge protocol to produce and simulate a relevant substrate, such as caries-affected dentin.