An electrospun nanocomposite fibrous material holds promise as a scaffold, as well as a drug-delivery device to aid in root maturogenesis and the regeneration of the pulp-dentine complex. A novel three-dimensional (3D) nanocomposite scaffold composed of polydioxanone (PDS II®) and halloysite nanotubes (HNTs) was designed and fabricated by electrospinning. Morphology, structure, mechanical properties and cell compatibility studies were carried out to evaluate the effects of HNTs incorporation (0.5-10 wt% relative to PDS w/w). Overall, a 3D porous network was seen in the different fabricated electrospun scaffolds, regardless of the HNT content. The incorporation of HNTs at 10 wt% led to a significant (p < 0.0001) fibre diameter increase and a reduction in scaffold strength. Moreover, PDS-HNTs scaffolds supported the attachment and proliferation of human-derived pulp fibroblast cells. Quantitative proliferation assay performed with human dental pulp-derived cells as a function of nanotubes concentration indicated that the HNTs exhibit a high level of biocompatibility, rendering them good candidates for the potential encapsulation of distinct bioactive molecules. Collectively, the reported data support the conclusion that PDS-HNTs nanocomposite fibrous structures hold potential in the development of a bioactive scaffold for regenerative endodontics.

The low concentrations of intracanal medicaments tested in this study were not cytotoxic in cultured cells. However, these concentrations are much lower than the concentrations that have been advocated in endodontic regeneration. Furthermore, the negative effects of TAP on DPCs were detected at lower concentrations by using the WST-1 assays than by measuring the LDH release.

PURPOSE This in-vitro study evaluated and compared the color stability of 3D-printed and conventional heat-polymerized acrylic resins following aging, mechanical brushing, and immersion in staining medium. MATERIALS AND METHODS Forty disc-shaped specimens (10 mm in diameter and 3 mm thick) were prepared from two 3D-printed [DentaBASE (DB) and Denture 3D+ (D3D)] and one conventional polymethylmethacrylate (PMMA) denture materials. The specimens were thermo-cycled, subjected to mechanical brushing, and were immersed in either coffee, lemon juice, coke, or artificial saliva (AS) to simulate one and two years of oral use. Color measurements of the specimens were recorded by a spectrophotometer at baseline (T0), and after one (T1) and two years (T2) of simulation. The color changes (∆E) were determined and also quantified according to the National Bureau of Standards (NBS) units. Descriptive statistics, followed by factorial ANOVA and Bonferroni post-hoc test (α=.05), were applied for data analysis. RESULTS The independent factors, namely material, staining medium, and immersion time, and interaction among these factors significantly influenced ∆E ( P <.009). Irrespective of the materials, treatments, and time, the highest and the lowest mean ∆Es were observed for PMMA in lemon juice (4.58 ± 1.30) and DB in AS (0.41 ± 0.18), respectively. Regarding the material type, PMMA demonstrated the highest mean ∆E (2.31 ± 1.37), followed by D3D (1.67 ± 0.66), and DB (0.85 ± 0.52), and the difference in ∆E between the materials were statistically significant ( P <.001). All the specimens demonstrated a decreased color changes at T2 compared to T1, and this difference in mean ∆E was statistically significant ( P <.001). CONCLUSION The color changes of 3D-printed denture resins were low compared to conventional heat polymerized PMMA. All the tested materials, irrespective of the staining medium used, demonstrated a significant decrease in ∆E values over time.