This study evaluated the effect of a 0.5% chloramine T solution on a chemical-cured universal adhesive by comparing the light-cured, one-step, self-etch adhesive for the bonding performance, mechanical properties, and resin–dentin interfacial characteristics. Caries-free human molars were randomly assigned into eight groups based on the bonding systems employed (Bond Force II, BF and Bondmer Lightless, BL), the immersion solutions used before bonding (0.5% chloramine T solution and distilled water), and the immersion durations (5 and 60 min). Microtensile bond strength (μTBS), nanoleakage evaluation, and nanoindentation tests were performed, and the surface morphology of the resin–dentin interface was examined using a focus ion beam/scanning ion microscopy system. Immersion in chloramine-T for 5 min significantly decreased the μTBS of Bondmer Lightless (from 22.62 to 12.87 MPa) compared with that in distilled water. Moreover, there was also a decreasing trend after immersing in chloramine-T for 60 min (from 19.11 to 13.93 MPa). Chloramine T was found to have no effect on the hardness, elastic modulus, or morphological characteristics of the ion-beam milled resin–dentin interfacial surfaces in the tested adhesives, suggesting that chloramine T might reduce the bond strength by interfering with the interaction and the sealing between the adhesive resin and dentin in the chemical-cured universal adhesive, albeit without affecting the mechanical properties.

Self-adhering flowable composites (SAFCs) were developed to simplify restorative procedures by eliminating separate adhesive steps; however, their bonding performance, mechanical properties, and biological properties remain controversial. This study evaluated a newly developed SAFC (SA-100R) compared with three commercial SAFCs (Fusio Liquid Dentin, Constic, and Vertise Flow) and a conventional composite (Clearfil AP-X used with a two-step self-etch adhesive). Microtensile bond strength (μTBS) to dentin, failure modes, Knoop microhardness, resin–dentin interfacial morphology (SEM), elemental composition (EDX), and cytocompatibility (CCK-8, LIVE/DEAD staining) were assessed. The conventional composite system exhibited significantly higher µTBS than all SAFCs (p < 0.05). Among SAFCs, SA-100R showed the highest bond strength and no pre-testing failures. SEM revealed abundant resin tag formation only in the conventional system, while all SAFCs showed interfacial gaps, with SA-100R exhibiting the least pronounced gaps. SA-100R showed no significant cytotoxic effects across all tested concentrations. Within the limitations of this short-term in vitro investigation, SA-100R demonstrated improved bonding performance and favorable biocompatibility compared with existing SAFCs, suggesting its potential as a simplified restorative material. However, the conventional adhesive/composite system remains the reference standard for dentin bond strength, and long-term clinical performance remains to be established through further studies.

Human dental pulp stem cells (hDPSCs) hold significant promise for bone regeneration, yet efficient osteogenic induction remains challenging. Phosphorylated oligosaccharides of calcium (POs‐Ca), a novel calcium salt derived from potato starch, has recently attracted attention for its remineralization capabilities and potential to promote stem cell differentiation. Here, we investigated the impact of POs‐Ca on the osteogenic differentiation of hDPSCs and its underlying mechanism. Isolated hDPSCs were characterized via flow cytometry based on mesenchymal surface markers. Biocompatibility and osteogenic differentiation were assessed via Cell Counting Kit‐8 (CCK‐8) assay, alkaline phosphatase (ALP) activity, Alizarin Red S staining, and protein levels of osteogenic (Collagen I, DSPP, DMP1, and RUNX2). Intracellular Ca ²⁺ flux was monitored using Fluo‐4 AM, while AMP‐activated protein kinase (AMPK) signaling and autophagic flux were analyzed by western blot (p‐AMPK, p‐ULK1, and light chain 3 (LC3)‐II), TEM, and LC3‐GFP imaging. Mechanistic studies employed verapamil (Ca ²⁺ channel blocker), Compound C (CC;AMPK inhibitor), and chloroquine (CQ;autophagy inhibitor). POs‐Ca (5 mg/mL) exhibited excellent biocompatibility and significantly promoted osteogenic differentiation, as evidenced by a 3.22‐fold increase in ALP activity and markedly enhanced mineralized nodule formation as shown by Alizarin Red S staining. Mechanistic studies revealed that POs‐Ca triggers rapid intracellular Ca ²⁺ influx, activating the AMPK pathway and inducing autophagic flux. Pharmacological inhibition established the essential causality of this cascade: verapamil abolished osteogenic enhancement, while CC and CQ suppressed ALP activity, mineralization, and osteogenic marker expression. Notably, CQ reciprocally attenuated POs‐Ca‐induced Ca ²⁺ influx, revealing novel bidirectional Ca ²⁺ ‐autophagy crosstalk. In conclusion, POs‐Ca might promote hDPSCs osteogenesis via a calcium influx‐driven AMPK‐autophagy axis, providing a foundation for novel biomaterials that exploit physiological calcium signaling. These findings offer immediate translational potential for developing minimally invasive, cost‐effective strategies in dental pulp regeneration and bone defect repair.