Polyelectrolytes such as polyaspartic acid (PAsp) are critical in biomimetic mineralization as stabilizers of amorphous calcium phosphate (ACP) precursors and as nucleation inhibitors similar to non-collagenous proteins (NCPs). Nevertheless, the application of polyelectrolyte–calcium complexes as a pre-precursor, such as PAsp–Ca complexes, in the mineralization of collagen is unexplored. Herein, we propose a polyelectrolyte–Ca complex pre-precursor (PCCP) process for collagen mineralization. By combining three-dimensional (3D) STORM, potential measurements, and cryogenic transmission electron microscopy with molecular dynamics simulations, we show that liquid-like electropositive PAsp–Ca complexes along with free calcium ions infiltrate electronegative collagen fibrils. The PAsp–Ca complexes are immobilized within the fibrils via chelation and hydrogen bonds, and outward movement of free calcium ions is prevented while phosphate and hydroxide are recruited through electrostatic attractions. Afterwards, ACP instantly forms and gradually crystallizes. The PCCP process not only unites two distinct crystallization pathways (classical (free Ca/P ions) and non-classical (polyelectrolyte–Ca complexes)), but also provides a novel strategy for rapid biomimetic mineralization of collagen.

We propose a novel fluorescent adhesive-assisted biomimetic mineralization strategy, based on which 1 wt% of sodium fluorescein and 25 wt% of polyacrylic acid stabilized amorphous calcium phosphate (PAA-ACP) nanoparticles were incorporated into a mild self-etch adhesive (Clearfil S3 Bond) as a fluorescent mineralizing adhesive. The characterization of the PAA-ACP nanoparticles indicates that they were spherical particles clustered together, each particle with a diameter of approximately 20–50 nm, in a metastable phase with two characteristic absorption peaks (1050 cm⁻¹ and 580 cm⁻¹). Our results suggest that the fluorescent mineralizing adhesive was non-cytotoxic with minimal esthetic interference and its fluorescence intensity did not significantly decrease within 6 months. Our data reveal that the fluorescent mineralizing adhesive could induce the extra- and intra-fibrillar remineralization of the reconstituted type I collagen, the demineralized enamel and dentin substrate. Our data demonstrate that a novel fluorescent adhesive-assisted biomimetic mineralization strategy will pave the way to design and produce anti-carious materials for the prevention of dental caries.

Background: Widespread exposure to phthalates may raise the probability of various diseases. However, the association of phthalate metabolites with periodontitis remains unclear. Methods: Totally 3402 participants from the National Health and Nutrition Examination Survey (NHANES) 2009 to 2014 cycles were enrolled in the cross-sectional investigation. We utilized weighted logistic regression to evaluate the association of ten phthalate metabolites with periodontitis. Restricted cubic spline analysis was applied to investigate potential nonlinear relationships. Results: The weighted prevalence of periodontitis in the study was 42.37%. A one standard deviation (SD) rise in log-transformed levels of mono-2-ethyl-5-carboxypenty phthalate (MECPP), mono-n-butyl phthalate (MnBP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-isobutyl phthalate (MiBP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-benzyl phthalate (MBzP) was associated with higher odds of periodontitis, with odds ratios (95% confidence intervals) of 1.08 (1.02-1.14), 1.07 (1.02-1.11), 1.10 (1.05-1.15), 1.05 (1.01-1.09), 1.09 (1.04-1.14), and 1.08 (1.03-1.13), respectively. Individuals with the highest quartile concentrations of MECPP, MnBP, MEHHP, MEOHP, and MBzP were associated with 32%, 20%, 30%, 25%, and 26% increased odds of periodontitis, respectively, compared to those with the lowest quartile. Additionally, mono-(3-carboxypropyl) phthalate (MCPP) demonstrated an interesting inverted J-shaped relationship with periodontitis. Conclusions: The findings indicate an association of certain phthalate metabolites with periodontitis among US adults.

Background: Dens invaginatus (DI) is a developmental anomaly, Oehlers Type III DI is the most complex type and early diagnosis and treatment is complicated and challenging. This report presents a rare case of a type IIIb DI associated with a periapical lesion in bilateral immature permanent mandibular central incisors. Case presentation: An eight-year-old boy referred to our clinic manifesting with pain along with swelling in the mandibular incisors for the past one month. Radiographic examination showed periapical radiolucency exhibiting a scantly defined border, as well as an invagination which had a central invaginated canal extending from the pulp chamber throughout the apical foramen in both mandibular central incisors. We performed two different treatment procedures on the basis of the condition of the main pulp of the mandibular central incisors. in which only the invagination root canal was treated in the right mandibular central incisor, while the invagination and main root canals were treated in the left mandibular central incisor. During the 18-month follow-up period, the teeth were clinically asymptomatic. Imaging examinations indicated complete healing of the periapical lesion and revealed that the wall of the root canal was thickened and the open apex was closed. Conclusion: For young permanent teeth with type III Dens invaginatus, it is particularly important to keep pulp vitality, which could maintain root development and allow a good long-term prognosis.