Periodontitis is a chronic inflammatory disease that progressively destroys periodontal tissues and alveolar bone, posing a significant challenge for clinical regeneration. Tissue engineering strategies integrating stem cells, biomaterials, and bioactive agents hold promise for overcoming the limitations of current periodontal regenerative approaches. In this study, we developed an injectable PLGA composite microscaffold-based co-delivery system with a porous architecture for the combined delivery of icariin (ICA) and bone marrow-derived mesenchymal stem cells (BMSCs). ICA-loaded PLGA composite microscaffolds (ICA-PLGA) were fabricated by a double emulsion-solvent evaporation method, followed by fibrinogen (Fg) surface modification via electrostatic layerby-layer assembly to generate ICA-PLGA-Fg microscaffolds with improved cell-adhesive properties. These porous microscaffolds exhibited sustained ICA release for up to 28 days and enhanced BMSC adhesion and spreading. In vitro, ICA-PLGA-Fg supported favorable cytocompatibility and enhanced osteogenic differentiation of BMSCs under inflammatory conditions. In vivo, BMSC-seeded ICA-PLGA-Fg constructs implanted into rat periodontitisrelated alveolar bone defects achieved markedly greater bone regeneration compared with both periodontitis and PLGA-only controls. Collectively, this co-delivery platform integrates sustained ICA release with a bioactive, cellsupportive microscaffold interface, promotes osteogenic responses in vitro, and shows therapeutic promise for enhancing periodontal bone repair in vivo.

Traumatic oral ulcers, arising from local physicochemical or mechanical stimuli, exhibit considerable discomfort, an extended healing period, and a potential for malignant transformation. Existing etiological treatments mainly include antibacterial therapy and promoting ulcer healing. Nevertheless, antibacterial therapy using antibiotics may cause unexpected side effects and drug resistance. Additionally, commonly used wound-healing drugs, such as growth factors and glucocorticoids, have drawbacks including instability, high cost, and systemic adverse reactions. To address these issues, a magnesium-incorporated photosensitive metal-organic framework (MOF) derivant, denoted as MgO/C, was developed by pyrolysis of Mg-MOF74. The MgO/C was characterized using scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The established MgO/C showed an excellent photothermal antibacterial performance upon prevalent oral ulcer pathogens under near-infrared light irradiation, featured by antibacterial rates of 97.8% and 96.5% against Streptococcus mutans and Staphylococcus aureus, respectively. Moreover, the MgO/C exhibited controlled release of magnesium ions for up to four days and effectively enhanced fibroblast proliferation, migration and adhesion, at an optimal concentration of 200 ppm. A rat traumatic oral ulcer model demonstrated that the MgO/C+NIR group could facilitate ulcer healing in vivo, resulting in an increase of wound healing rate by 23.4%, in comparison to the control on day 3. Our study revealed that MgO/C had great potential for the treatment of traumatic oral ulcers.

Root caries is a subtype of dental caries that predominantly impacts older adults. The occurrence and progression of root caries are associated with the homeostasis of dental plaque biofilm, and microbial synergistic and antagonistic interactions in the biofilm play a significant role in maintaining the oral microecological balance. The objective of the current study was to investigate the role of Veillonella parvula in the microbial interactions and the pathogenesis of root caries. The analysis of clinical samples from patients with/without root caries revealed that Veillonella and V. parvula were abundant in the saliva of patients with root caries. More importantly, a significantly increased colonization of V. parvula was observed in root carious lesions. Further in vitro biofilm and animal study showed that V. parvula colonization increased the abundance and virulence of Streptococcus mutans and Candida albicans, leading to the formation of a polymicrobial biofilm with enhanced anti-stress capacity and cariogenicity, consequently exacerbating the severity of carious lesions. Our results indicate the critical role of V. parvula infection in the occurrence of root caries, providing a new insight for the etiological investigation and prevention of root caries.

Oral microecological balance is closely associated with the development of dental caries. Oxidative stress is one of the important factors regulating the composition and structure of the oral microbial community. Streptococcus mutans is linked to the occurrence and development of dental caries. The ability of S. mutans to withstand oxidative stress affects its survival competitiveness in biofilms. The oxidative stress regulatory mechanisms of S. mutans include synthesis of reductase, regulation of metal ions uptake, regulator PerR, transcription regulator Spx, extracellular uptake of glutathione, and other related signal transduction systems. Here, we provide an overview of how S. mutans adapts to oxidative stress and its influence on oral microecology, which may offer novel options to investigate the cariogenic mechanisms of S. mutans in the oral microenvironment, and new targets for the ecological prevention and treatment of dental caries.

The oral microecological balance is closely associated with the development of dental caries. Oxidative stress is one of the important factors regulating the composition and structure of the oral microbial community. Streptococcus mutans is closely related to the occurrence and development of dental caries. The ability of S. mutans to withstand oxidative stress affects its survival competitiveness in biofilms. The oxidative stress regulatory mechanisms of S. mutans include the synthesis of reductase, the regulation of iron and manganese uptake by metalloregulatory proteins, transcription regulator Spx, extracellular uptake of glutathione and other related signal transduction systems. The current research focuses on how S. mutans adapts to a complex external environment through an oxidative stress response and its influence on oral microecology. We can design targeted small molecular compounds for key signaling pathways to inhibit oxidative stress and weaken the virulence of S. mutans, which is important for oral microecological modulation and dental caries prevention and treatment.

Background The relationship between dietary and drinking water habits and oral health are still unclear. We aimed at evaluating the association of dietary and drinking water habits with number of teeth in the elderly adults. Methods We conducted a longitudinal study based on the Chinese Longitudinal Healthy Longevity Survey from 1998 to 2018. The data of dietary and drinking water habits at baseline were collected using a questionnaire. The number of teeth at baseline and follow-up was collected for each subject. We used the linear mixed-effect model to analyze the associations of dietary habits and drinking water sources with tooth number. Results Among 19,896 participants at baseline, the mean age of the participants was 83.87 years, with the average number of natural teeth of 9.37, 8.26, 8.38, 8.68, 4.05, 1.92, 1.12, 2.20 for the first to eighth waves of survey. Compared with subjects drinking tap water, 1.036 ( 95 % CI : -1.206, -0.865), 0.880 ( 95 % CI : -1.122, -0.637) and 1.331 ( 95 % CI : -1.715, -0.947) fewer natural teeth were reported for those drinking well, surface water and spring at baseline survey. Compared with participants with rice intake as the staple food, those with wheat intake ( β = -0.684; 95 % CI : -0.865, -0.503) tended to have fewer natural teeth. Compared with participants with fresh fruit intake almost every day, those with quite often intake of fresh fruit tended to have fewer teeth with a significant dose-response trend ( P trend <0.001). Similar decreased trend for number of teeth was also indicated for increased frequency of vegetable intake ( P trend <0.001). Fewer number of teeth was found for subjects with less frequency of meat and fish intakes. Conclusions The study suggested that drinking well, surface water, and spring, intakes of wheat as staple food, as well as less frequency of fresh fruit, vegetable, meat and fish intakes were associated with significantly fewer number of teeth in the Chinese elderly population.

Introduction: The purpose of this study was to evaluate the two-body wear resistances of natural enamel and four dental materials in vitro. Methods: The testing machine was modified to form a type of pin-on-disk wear test apparatus. Four dental material specimens (Au-Pd alloy, Ag-Pd alloy, FiltekTMP60 and FiltekTMZ350 composite resins) and enamel were used as the pins, and a steatite ceramic grinding wheel was used as the abrasive counter face. The wear volume loss and the rigidity value was measured. The worn surface and the element analysis of the debris were analyzed. Result: The wear volume loss of Au-Pd alloy and its steatite antagonists were the nearest to those of the dental enamel. SEM microphotographs showed that, the main wear mechanism of the dental materials was abrasive and adhesive wear. Conclusions: Au-Pd alloy had good wear resistance and was more suitable for dental applications than other three dental materials.

Purpose: Icariin (ICA) is one of the main active constituents of Herba Epimedii for improving osteogenesis. It is necessary to create a simple and efficient method to load ICA onto the surface of titanium (Ti) implant. The purpose of this study was to establish a local ICA delivery system via a layer-by-layer (LbL) self-assembly system on phase-transited lysozyme (PTL)-primed Ti surface. Materials and methods: A PTL nanofilm was first firmly coated on the pristine Ti. Then, the ICA-loaded hyaluronic acid/chitosan (HA/CS) multilayer was applied via the LbL system to form the HA/CS-ICA surface. This established HA/CS-ICA surface was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and contact angle measurement. The ICA release pattern of the HA/CS-ICA surface was also examined. MC3T3-E1 osteoblast culture test and a rat model were used to evaluate the effects of the HA/CS-ICA surface in vitro and in vivo. Results: SEM, XPS and contact angle measurement demonstrated successful fabrication of the HA/CS-ICA surface. The HA/CS-ICA surfaces with different ICA concentrations revealed a controlled release profile of ICA during a 2-week monitoring span. Osteoblasts grown on the coated substrates displayed higher adhesion, viability, proliferation and ALP activity than those on the polished Ti surface. Furthermore, in vivo histological evaluation revealed much obvious bone formation in the ICA-coated group by histological staining and double fluorescent labeling at 2 weeks after implantation. Conclusion: The present study demonstrated that ICA-immobilized HA/CS multilayer on the PTL-primed Ti surface had a sustained release pattern of ICA which could promote the osteogenesis of osteoblasts in vitro and improve early osseointegration in vivo. This study provides a novel method for creating a sustained ICA delivery system to improve osteoblast response and osseointegration.