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.

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.

Objective: A dihydropyridine-type calcium channel blocker, benidipine (BD), is extensively used in hypertension therapy. In vitro study reported BD promoting bone metabolism. We evaluated the effect of sustained release of BDloaded poly(lactic-co-glycolic acid) (PLGA) microcarriers on the promotion of bone and gingival healing at an extraction socket in vivo. In addition, the effect of BD on osteoblasts, osteocytes, fibroblasts, and epithelial cells was evaluated in vitro. Approach: The maxillary first molar of rats was extracted. Next, PLGA microcarriers containing BD were directly injected into the gingivobuccal fold as a single dose. After injection, bone and soft-tissue healing was histologically evaluated. Effect of BD on proliferation, migration, and gene expression of gingival and bone cell was also examined in vitro. Results: After tooth extraction, BD significantly augmented bone volume and density, and also epithelial wound healing. During in vitro studies, BD promoted significant proliferation and migration of fibroblasts and epithelial cells. Real-time RT-PCR revealed that BD upregulated messenger RNA expression of Ahsg (alpha 2-HS glycoprotein) and Csf2 (colony-stimulating factor 2) in osteoblasts. Innovation: The prevention of bone and soft-tissue reduction associated with tooth extraction has been eagerly anticipated in the field of dentistry. This study first reported the effect of BD on extraction socket healing. Conclusion: A single dose of topically administered BD-loaded PLGA microcarriers promoted bone and soft-tissue healing at the extraction site of tooth.

Zirconia materials have been increasingly used in implant rehabilitation due to their excellent physical and esthetic properties. Stable peri‐implant epithelial tissue adhesion to the transmucosal implant abutment may significantly enhance the efficacy of implant long‐term stability. However, it is difficult to form stable chemical or biological bindings with peri‐implant epithelial tissue due to the strong biological inertia of zirconia materials. In the present study, we investigated whether calcium hydrothermal treatment of zirconia promotes sealing of peri‐implant epithelial tissue. In vitro experiments were performed to analyze the effects of calcium hydrothermal treatment on zirconia surface morphology and composition by scanning electron microscopy and energy dispersive spectrometry. Immunofluorescence staining of adherent proteins, namely, F‐actin and integrin β1, in human gingival fibroblast line (HGF‐l) cells was performed. In the calcium hydrothermal treatment group, there was higher expression of these adherent proteins and increased HGF‐l cell proliferation. An in vivo study was conducted by extracting the maxillary right first molars of rats and replacing them with mini‐zirconia abutment implants. The calcium hydrothermal treatment group showed better attachment at the zirconia abutment surface, which inhibited horseradish peroxidase penetration at 2 weeks post‐implantation. These results demonstrated that calcium hydrothermal treatment of zirconia improves the seal between the implant abutment and surrounding epithelial tissues, potentially increasing the long‐term stability of the implant.