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Background: Acute kidney injury (AKI) is characterized by rapid renal decline. Periodontitis, a chronic oral inflammatory disease, is increasingly associated with renal dysfunction. Although periodontitis is recognized as a contributor to kidney damage, the mechanisms linking it to AKI remain unclear. Methods: This study explored the effects of Porphyromonas gingivalis (P. gingivalis) W83‐infected periodontitis on AKI in C57BL/6J mice, using ischemia‐reperfusion injury 55 days post‐infection. Gingipain inhibitors, KYT‐1 and KYT‐36, were applied. Detection of P. gingivalis was performed using quantitative real‐time polymerase chain reaction (qRT‐PCR) and PCR, while transcriptome sequencing, qRT‐PCR, immunohistochemistry, and immunofluorescence staining assessed renal damage. In vitro, HK‐2 cells were exposed to P. gingivalis at a multiplicity of infection of 10 for 48 h, with inhibition by gingipain or oncostatin M (OSM). Disruption of tight junctions (TJs) was quantified using qRT‐PCR, transepithelial electrical resistance, and cell counting kit‐8 assays. Results: Periodontitis worsened AKI, linked to P. gingivalis infection and renal TJ disruption in the kidney. P. gingivalis infection activated OSM expression, which correlated positively with gingipain. Significantly, OSM and gingipain might collaboratively contribute to the damage of renal TJs, with the reduced expression of TJ proteins. Suppressing gingipain activity presented itself as a protective strategy against the destruction of TJs and the attendant worsening of AKI due to periodontitis. Conclusions: Our study enhances the understanding of the interplay between periodontitis and AKI, highlighting the harmful impact of P. gingivalis in AKI. [ABSTRACT FROM AUTHOR]

Background: Tooth loss is closely related to cognitive impairment, especially affecting cognitive functions involving hippocampus. The most well‐known function of the hippocampus is learning and memory, and the mechanism behind is neuroplasticity, which strongly depends on the level of brain‐derived neurotrophic factor (BDNF). While research has delved into the possible mechanisms behind the loss of teeth leading to cognitive dysfunction, there are few studies on the plasticity of sensory neural pathway after tooth loss, and the changes in related indicators of synaptic plasticity still need to be further explored. Methods: In this study, the bilateral maxillary molars were extracted in Sprague–Dawley rats of two age ranges (young and middle age) to establish occlusal support loss model; then, the spatial cognition was tested by Morris Water Maze (MWM). Quantitative real‐time PCR (qPCR) and Western Blotting (WB) were used to detect BDNF, AKT, and functional proteins (viz., PSD95 and NMDAR) of hippocampal synapses. Golgi staining was used to observe changes in ascending nerve pathway. IF was used to confirm the location of BDNF and AKT expressed in hippocampus. Results: MWM showed that the spatial cognitive level of rats dropped after occlusal support loss. qPCR, WB, and IF suggested that the BDNF/AKT pathway was down‐regulated in the hippocampus. Golgi staining showed the neurons of ascending sensory pathway decreased in numbers. Conclusion: Occlusal support loss caused plastic changes in ascending nerve pathway and induced cognitive impairment in rats by down‐regulating BDNF and synaptic plasticity. [ABSTRACT FROM AUTHOR]

Background: Both animal studies and prospective observational studies on patients with neurodegenerative disease have reported a positive link between oral diseases and cognitive function. However, the effect of early tooth loss on hippocampal morphology remains unknown. Methods: In this study, 6-week-old, male, juvenile Sprague–Dawley (SD) rats were randomized into the control (C) and tooth loss (TL) groups. In the TL group, all right maxillary molars of SD rats were extracted, while in the C group, no teeth were extracted. After 3 months, the learning and memory behavior were examined by Morris Water Maze (MWM), and the protein expression and mechanic signaling pathways were analyzed by real-time polymerase chain reaction, and cresyl violet staining. Results: Two days after the operation, the body weight of both groups recovered and gradually returned to the level before operation. Three months after tooth extraction, the completion time of the C group in the MWM was significantly shorter than the TL group. The mRNA expression of BDNF, TrkB, AKT1 , and NR2B in the C group were significantly higher than in the TL group. The pyramidal neurons in the TL group was fewer than in the C group. Conclusion: Tooth loss in the juvenile SD rats will reduce the number of pyramidal neurons in the hippocampus, inhibit the expression of BDNF, TrkB, AKT1 , and NR2B , and eventually lead to cognitive dysfunction. [ABSTRACT FROM AUTHOR]

Objective: Mechanical plaque removal may alter the surface morphology of the gingival penetration part of the implant. We applied an air‐powered abrasive system (AP), titanium curette (TC), stainless curette (SC), ultrasound scaler (US), and titanium brush (TB) which are commonly used to remove plaque, to titanium or zirconia and the changes in surface morphology and the epithelial attach against substrata. Materials and Methods: (a) The morphological changes of titanium and zirconia after mechanical cleaning were assessed by scanning electron microscopy and a roughness analyser. (b) Oral epithelial cells of rats were inoculated on the surface of the materials after mechanical cleaning, and the adherence of epithelial cells was observed. (c) The maxillary first molars were extracted from the rats and replaced by experimental titanium or zirconia implants. The length of the immunoreactive laminin‐332 band was observed at the implant‐peri‐implant epithelium interface. Results: (a) The surface roughness increased in experimental groups except the AP group. (b) Among the experimental groups, the AP group showed the highest number of attached cells. (c) The length of the immunoreactive laminin‐332 band was longer in the control group than those in all five experimental groups. Among the experimental groups, the AP group showed the longest band. Conclusion: All mechanical cleaning methods increased the surface roughness of the materials except AP. AP did not cause distinct implant surface alterations. Surface alteration caused by mechanical cleaning may evoke inferior for epithelial attachment and reduce resistance against foreign infiltration. [ABSTRACT FROM AUTHOR]

Zirconia is widely employed as a material during dental implant work because of its superior esthetics. This study sought to evaluate the impact of titanium or zirconia implant abutments on epithelial attachments after ultrasonic cleaning. These implants were inserted into the extraction socket of rat maxillary first molars. Then, the length of the horseradish peroxidase (HRP) reaction was measured. In addition, titanium and zirconia disks were cleaned using an ultrasonic scaler, surface morphology changes were observed, and the number of epithelial cell attachments to the surface was measured. Ultimately, the surfaces of the titanium disks were easier to damage than those of the zirconia ones. There was no difference in the number of epithelial cell attachments between the two materials with the ultrasonic cleaning. The length of the HRP reaction was shorter on the zirconia implant abutment surface than on the titanium one after mechanical cleaning. In conclusion, zirconia is harder than titanium and a better choice for use in the epithelial tissue attachment. Zirconia is more suitable as a material for implant abutments than titanium. [ABSTRACT FROM AUTHOR]

The improvement of peri-implant epithelium (PIE) adhesion to titanium (Ti) may promote Ti dental implant stability. This study aims to investigate whether there is a positive effect of Ti hydrothermally treated (HT) with calcium chloride (CaCl2), zinc chloride (ZnCl2), and strontium chloride (SrCl2) on promoting PIE sealing. We analyzed the response of a rat oral epithelial cell (OEC) culture and performed an in vivo study in which the maxillary right first molars of rats were extracted and replaced with calcium (Ca)-HT, zinc (Zn)-HT, strontium (Sr)-HT, or non-treated control (Cont) implants. The OEC adhesion on Ca-HT and Zn-HT Ti plates had a higher expression of adhesion proteins than cells on the Cont and Sr-HT Ti plates. Additionally, the implant PIE of the Ca-HT and Zn-HT groups revealed better expression of immunoreactive laminin-332 (Ln-322) at 2 weeks after implantation. The Ca-HT and Zn-HT groups also showed better attachment at the implant–PIE interface, which inhibited horseradish peroxidase penetration. These results demonstrated that the divalent cations of Ca (Ca2+) and Zn (Zn2+)-HT improve the integration of epithelium around the implant, which may facilitate the creation of a soft barrier around the implant to protect it from foreign body penetration. [ABSTRACT FROM AUTHOR]

Background: Although alveolar bone resorption after the tooth extraction is unavoidable, the preservation of alveolar ridge has been expected. The dihydropyridine‐type calcium channel blocker, benidipine (BD) has been widely used as an antihypertensive, and recently some reports indicated the anabolic effect of BD on bone. We novelly developed BD‐loaded poly (lactic‐co‐glycolic acid) (PLGA) microspheres with sustained‐release characteristics as a possible socket preservative. Aim/Hypothesis: The aim of the present study was to examine the effect of BD on bone healing using rodent tooth extraction model with newly‐developed drug delivery system. In parallel, the effect of BD on the gene expression of hard and soft tissue cells was examined using culture study. Material and Methods: The maxillary right first molars of 5‐week‐old Wistar rats were extracted and immediately injected the suspension of BD‐loaded (or non‐loaded as a control) PLGA microspheres once, into the gingivobuccal fold just proximal to the socket. At days 1, 3, 7 and 28 after the injection, the extraction socket healing was histologically evaluated. As culture studies, the effect of BD on the proliferation of osteoblast (MC3T3‐E1), osteocyte (MLO‐Y4), fibroblast (NIH3T3) and gingival epithelial cell (GE1) was measured at the concentrations of 0, 0.1, to 10,000 nM. The effect of BD on cell migration was also observed in fibroblastic and gingival epithelial cell culture. Real‐time RT‐PCR array assay was performed using osteoblastic and osteocytic cell culture with the concentration of 100 nM BD. Results: Animal study revealed that the single injection of BD‐loaded PLGA microspheres significantly augmented bone volume and density at the extraction socket. In vitro study demonstrated that BD significantly promoted the proliferation of every tested cell. BD also enhanced the cell migration of NIH3T3 and GE1. RT‐PCR assay indicated that BD up‐regulated the mRNA expressions of Ahsg and Csf‐2 in MC3T3‐E1 and Bmp4 and Bmp6 in MLO‐Y4. Conclusions and Clinical Implications: This study demonstrated that a single topical application of BD‐loaded PLGA microspheres promoted extraction socket healing in vivo. Culture study exhibited the BD accelerating both proliferation and migration of bone and soft tissue cells. The expressions of some genes were activated, consistent with the evidence that BD group had an anabolic effect on bone metabolism. These results presented possibilities of BD as a locally‐administrable socket‐preservative or anti‐bone resorption agent. [ABSTRACT FROM AUTHOR]

Injectable calcium phosphate cement (CPC) offers significant benefits for the minimally invasive repair of irregular bone defects. However, the main limitations of CPC, including its deficiency in osteogenic properties and insufficient large porosity, require further investigation and resolution. In this study, alginate-chitosan-alginate (ACA) microcapsules were used to encapsulate and deliver rat bone mesenchymal stem cells (rBMSCs) into CPC paste, while a porous CPC scaffold was established to support cell growth. Our results demonstrated that the ACA cell microcapsules effectively protect the cells and facilitate their transport into the CPC paste, thereby enhancing cell viability post-implantation. Additionally, the ACA + CPC extracts were found to stimulate osteogenic differentiation of rBMSCs. Furthermore, results from a rat cranial parietal bone defect model showed that ACA microcapsules containing exogenous rBMSCs initially improved the in situ osteogenic potential of CPC within bone defects, providing multiple sites for bone growth. Over time, the osteogenic potential of the exogenous cells diminishes, yet the pores created by the microcapsules persist in supporting ongoing bone formation by recruiting endogenous cells to the osteogenic sites. In conclusion, the utilization of ACA loaded stem cell microcapsules satisfactorily facilitate osteogenesis and degradation of CPC, making it a promising scaffold for bone defect transplantation., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

Gingival fibroblasts play an important role in the constitution of soft tissue attachment. This study aims to investigate whether porous zirconia coating has a positive effect on promoting human gingival fibroblast attachment. The porous zirconia coating was loaded on zirconia surface by the dip coating method, surface morphology and composition were confirmed by scanning electron microscope and energy dispersive spectrometer; Tested the tensile bond strength by universal testing machine; Tested the surface roughness by roughness analyzer; Human gingival fibroblast proliferation, integrin β 1 and F-actin immunofluorescence staining explored the influence of porous zirconia on the adhesion and proliferation of human gingival fibroblast. Zirconia0.2 group showed spherical zirconia particles with diameters of 3-8 μ m are distributed on the surface; The bonding strength of zirconia particle coating group reached 16.1±0.1 MPa, and the surface roughness was 0.715±0.091 μ m; In comparison with control group ( P < 0.01), the percentage of human gingival fibroblasts adhering to zirconia was markedly higher. In zirconia group, integrin- β 1 and F-actin fluoresced more obvious than in control group. Porous zirconia coating can form a porous structure on the surface and the porous structure can promote the attachment and proliferation of human gingival fibroblast, it will be more beneficial for soft tissue early sealing.

Zirconia is widely employed as a material during dental implant work because of its superior esthetics. This study sought to evaluate the impact of titanium or zirconia implant abutments on epithelial attachments after ultrasonic cleaning. These implants were inserted into the extraction socket of rat maxillary first molars. Then, the length of the horseradish peroxidase (HRP) reaction was measured. In addition, titanium and zirconia disks were cleaned using an ultrasonic scaler, surface morphology changes were observed, and the number of epithelial cell attachments to the surface was measured. Ultimately, the surfaces of the titanium disks were easier to damage than those of the zirconia ones. There was no difference in the number of epithelial cell attachments between the two materials with the ultrasonic cleaning. The length of the HRP reaction was shorter on the zirconia implant abutment surface than on the titanium one after mechanical cleaning. In conclusion, zirconia is harder than titanium and a better choice for use in the epithelial tissue attachment. Zirconia is more suitable as a material for implant abutments than titanium.

The purpose of this study was to evaluate the effects of an injectable composite made up of calcium sulfate (CAS), fluvastatin (FS), and atelocollagen on bone augmentation in rats. Porous structures and compressive strength of composites were evaluated. The cumulative release kinetics of FS were determined in vitro by a spectrophotometer. To observe bone regeneration in vivo, five different materials (normal saline; atelocollagen gel only; composite of CAS and atelocollagen; composite containing 0.5% FS; and composite containing 1.0% FS) were injected in extraction sockets and in the crania of rats. Microcomputed tomography and histological evaluation were performed after 2, 4, and 8 weeks of healing time. The composites had high porosity (greater than 55%). FS kept a slow and stable release for >30 days. In vivo results demonstrated that more new bone was formed in the FS groups compared with the other groups, and both bone mass and bone density had prominent increase in maxillae and crania. Resorption of the composite was also observed for cranial tissues. In conclusion, this composite can be applied percutaneously, without any incision. It has excellent properties with replaceability into bone and anabolic effects for bone formation, as well as a drug delivery system for bone formation.