中华口腔医学杂志最新文献

Temporomandibular joint osteoarthritis (TMJOA) is a kind of organic disease with synovial inflammation, cartilage degeneration and subchondral bone remodeling as the main pathological changes. The current treatment is mainly to relieve symptoms, but cannot completely stop the progression of the disease. Mesenchymal stem cells (MSC) have multi-lineage differentiation potential and have good prospects in the repair therapy of TMJOA. Intra-articular injection of MSC from bone marrow, adipose, umbilical cord, dental pulp, etc. has been shown to be effective in numerous animal studies. The above exogenous MSCs can also be used as seed cells to participate in tissue engineering and repair more severe defects. Recent studies have shown that exosomes are important mediators of MSC action and have some potential in the treatment of TMJOA. As the mechanisms of TMJOA are further investigated, there is some prospect that endogenous repair capacity can be activated by local injection of relevant drugs targeting the resident stem cells in the joint.

Objective: To investigate the effects of Porphyromonas gingivalis (Pg) persisters (Ps) on immuno-inflammatory responses in macrophages, and to explore the underlying mechanisms. Methods: Pg cells were cultured to the stationary phase (72 h), and subsequently treated by high concentration of metronidazole at 100 mg/L, amoxicillin at 100 mg/L and the combination of them for different time period, named as metronidazole group, amoxicillin group and (metronidazole+amoxicillin) group. Pg cells without treatment were used as Blank control. The survival profile of PgPs cells was measured by colony-forming unit assay. The living state of PgPs was observed by Live/Dead staining. Then, Pg and metronidazole-treated PgPs (M-PgPs) were used to treat macrophages, named as Pg group and M-PgPs group. Transmission electron microscopy (TEM) was used to observe the bacteria in the macrophages. The expression levels of proinflammatory cytokines in macrophages were determined by real-time fluorescence quantitative PCR and enzyme-linked immunosorbent assay. The location of forkhead box transcription factor 1 (FOXO1) was detected by confocal immunofluorescence microscopy. After inhibiting or enhancing the FOXO1 expressions using inhibitors (Fi) or activators (Fa) respectively, the macrophages were treated with Pg and M-PgPs, divided as Blank group, Pg group, M-PgPs group, Fi group, (Fi+Pg) group, (Fi+M-PgPs) group, Fa group, (Fa+Pg) group and (Fa+M-PgPs) group. Then, the expression pattens of proinflammatory cytokines were assessed. Results: Remarkable number of lived PgPs was observed, both in planktonic culture and Pg biofilms either treated with metronidazole, amoxicillin or both, and those persisters could form new colonies. Pg and M-PgPs were able to enter into the macrophages and the protein expression levels of interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor-α (TNF-α) [Pg group: (2 392±188), (162±29), (5 558±661), (789±155) μg/L; M-PgPs group: (2 415±420), (155±3), (5 732±782), (821±176) μg/L] were significantly upregulated than those in Blank group [(485±140), (21±9), (2 332±87), (77±7) μg/L] (P<0.01). Moreover, Pg and M-PgPs could facilitate the nuclear translocation and accumulation of FOXO1. In addition, the relative mRNA expression levels of FOXO1, B-cell lymphoma 6 and Krüppel-like factor 2 were upregulated when compared to Blank group (P<0.05). Furthermore, the protein expression levels of IL-1β, IL-6, IL-8 and TNF-α in Fi+Pg group [(1 081±168), (70±8), (1 976±544), (420±47) μg/L] were remarkably lower than Pg group [(4 411±137), (179±6), (5 161±929), (934±24) μg/L] (P<0.05). Similarly, the protein expression levels of IL-1β, IL-6, IL-8 and TNF-α in Fi+M-PgPs group [(1 032±237), (74±10), (1 861±614), (405±32) μg/L] were remarkably lower than M-PgPs group [(4 342±314), (164±17), (4 438±1 374), (957±25) μg/L] (P<0.05). On the contrary, the protein expression levels of IL-1β, IL-6, IL-8

Dental turbine is a commonly used instrument for oral clinical treatment. However, there is usually suckback during the using of the traditional dental turbine, which causes the pathogen residue in the pipeline of the dental comprehensive treatment table, leading to cross-infection. Zero suckback technology is a new oral treatment technology to avoid suckback during the usage of dental turbine, which can reduce the possibility of cross infection. However, the applications and methods of zero suckback technique in oral therapy remain to be clarified. This consensus mainly provides guidance for the clinical standard application of zero suckback technology from following aspects: field and definition, indications, applicable population, personnel requirements, operating process and evaluation of therapeutic effect.

Objective: To investigate the effect of zirconia personalized gingival structure on peri-implant soft and hard tissue stability after single-tooth implant restorations in patients with thin gingival biotypes in the anterior region, with a view to provide a clinical guideline. Methods: This retrospective study included 20 patients with thin gingival biotype and implant restorations in the anterior region. These patients included 9 males and 11 females, and the age was (35.2± 10.3) years. The patients were from the Department of Periodontal Implantology, Stomatology Hospital, Southern Medical University from January 2018 to December 2022. Computer-aided design/computer-aided manufacturing (CAD/CAM) techniques were used to fabricate a titanium base zirconia personalized gingival structure to maintain the soft-tissue perforated gingival contour of the anterior esthetic zone. This structure consists of two modalities: titanium base + zirconia outer crown or titanium base personalized zirconia abutment + zirconia outer crown. Clinical outcomes were recorded immediately and after delivery of the final restorations. Implant retention was recorded, esthetic scoring was performed using the pink esthetic index, the amount of bone resorption at the implant margins was measured based on digitized apical radiographs, and periodontal health was evaluated using the modified plaque index and the modified bleeding index. Results: The survival rate of the 20 implants was 100% after 3 years of wearing the final restorations, with a pink aesthetic score of 9.3±0.9. Bone resorption at the proximal and distal mesial margins of the implants was 0.09 (-0.21, 0.20) mm, 0.17 (-0.12, 0.27) mm after 3 years, respectively, and the difference was not statistically significant when compared to bone resorption immediately after placement of the final restoration [0(0, 0) mm] (Z=-1.03, P=0.394; Z=-2.05, P=0.065). Conclusions: Zirconia personalized gingival structure maintains the stability of peri-implant hard and soft tissues of thin gingival biotypes in the anterior region.

Objective: To investigate the presence of a distinct stem cell populations different from mesenchymal stem cells in the mandibular periosteum of both human and non-human primates (macaca mulatta), to explore its properties during intramembranous osteogenesis and to establish standard protocols for the isolation, culturing and expanding of mandibular periosteal stem cells (PSC) distinguished from other PSCs in other anatomical regions. Methods: Periosteum was harvested from the bone surface during flap bone removal in patients aged 18-24 years undergoing third molar extraction and from the buccal side of the mandibular premolar region of 6-year-old macaca mulatta respectively, and then subjected to single-cell sequencing using the Illumina platform Novaseq 6000 sequencer. Cross-species single-cell transcriptome sequencing results were compared using homologous gene matching. PSC were isolated from primary tissues using two digestion methods with body temperature and low temperature, and their surface markers (CD200, CD31, CD45 and CD90) were identified by cell flow cytometry. The ability of cell proliferation and three-lineage differentiation of PSC expanded to the third generation in vitro in different species were evaluated. Finally, the similarities and differences in osteogenic properties of PSC and bone marrow mesenchymal stem cells (BMSC) were compared. Results: The single-cell sequencing results indicated that 18 clusters of cell populations were identified after homologous gene matching for dimensionality reduction, and manual cellular annotation was conducted for each cluster based on cell marker databases. The comparison of different digestion protocols proved that the low-temperature overnight digestion protocol can stably isolate PSC from the human and m. mulatta mandibular periosteum and the cells exhibited a fibroblast-like morphology. This research confirmed that PSC of human and m. mulatta had similar proliferation capabilities through the cell counting kit-8 assay. Flow cytometry analysis was then used to identify the cells isolated from the periosteum expressed CD200(+), CD31(-), CD45(-), CD90(-). Then, human and m. mulatta PSC were induced into osteogenesis, adipogenesis, and chondrogenesis to demonstrate their corresponding multi-lineage differentiation capabilities. Finally, comparison with BMSC further clarified the oesteogenesis characteristics of PSC. The above experiments proved that the cells isolated from the periosteum were peiosteal cells with characteristics of stem cells evidenced by their cell morphology, proliferation ability, surface markers, and differentiation ability, and that this group of PSC possessed characteristics different from traditional mesenchymal stem cells. Conclusions: In this study, normal mandibular PSC from humans and m. mulatta were stably isolated and identified for the first time, providing a cellular foundation for investigating the mechanism of mand

Objective: To investigate the regulatory effect and mechanism of interleukin-22 (IL-22) on the gingival epithelial barrier in the context of periodontal inflammation. Methods: IL-22 knockout (IL-22 KO) mice were constructed, and periodontitis mice models were established through oral gavage with polymicrobial inoculation. DNAs were extracted from the oral plaques of IL-22 KO periodontitis mice group (n=7) and their wild-type littermates periodontitis group (n=7) to establish a periodontitis-related oral microbiota database"PD-RiskMicroDB", determining the relationship between changes in oral microbiota and microbial function in two groups using 16S rRNA sequencing results. Gingival epithelial cells (GEC) were cultured by modified trypsinization method, and were stimulated with 100 μg/L IL-22, Porphyromonas gingivalis (Pg) (multiplicity of infection:100), separately or together for 3 and 12 hours. The experimental groups were as follows: control group (no stimulation), IL-22 group, Pg group and Pg+IL-22 group. The expression of barrier protein E-cadherin in each group at 3 h was detected by immunofluorescence, real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting. Fluorescein isothiocyanate-dextran-mediated epithelial cell permeability experiment was conducted to clarify the changes in permeability of GEC in each group at 3 and 12 h. The mRNA expressions of E-cadherin in the gingival epithelium of wild-type littermates periodontitis group and IL-22 KO periodontitis group were detected by RT-qPCR. Fifteen C57BL/6 wild-type mice were randomly divided into control group (n=5), periodontitis group (n=5) and periodontitis+IL-22 treatment group (n=5). RT-qPCR and immunohistochemistry (IHC) staining were used to detect the expression level of E-cadherin in the gingival epithelium of each group. Results: 16S rRNA sequencing results showed that the composition of oral microbiota changed in IL-22 KO periodontitis group, of which the abundance of bacterial genera related to periodontal tissue invasion was significantly increased (linear discriminant analysis score: 2.22, P=0.009), compared with wild-type littermates periodontitis group. In vitro cell experiments showed that after Pg infection for 3 hours, the cell connections of GEC in Pg group were interrupted, and the fluorescence intensity of E-cadherin was reduced in Pg group compared with the control group. Meanwhile, the mRNA and protein expression levels of E-cadherin (mRNA: 0.69±0.12; protein: 0.60±0.12) were downregulated compared with the control group [mRNA: 1.00±0.00 (P=0.043); protein: 1.04±0.08 (P=0.003)], respectively. The fluorescence intensity of E-cadherin in the Pg+IL-22 group was enhanced compared with Pg group, and expression levels of E-cadherin mRNA (1.16±0.10) and protein (0.98±0.07) in Pg+IL-22 group showed a significant increase compared with Pg group [mRNA: 0.69±0.12 (<

Patients with severe alveolar ridge defects cannot be directly implanted and repaired, which seriously affects their quality of life. Onlay bone grafting is the main solution for severe alveolar ridge bone defect reconstruction, among which autogenous block bone grafting is the most widely used and is also the focus of clinical research on bone tissue reconstruction. This article expounds the characteristics and basic principles of autogenous bone block grafting, and comprehensively analyzes the selection of autogenous bone donor site, the principles of surgical operation, and the progress of bone graft techniques. In order to help surgeons make correct clinical decisions, increase the predictability of surgical effects, and improve the level of clinical diagnosis and treatment.

Objective: To investigate the therapeutic effect of methotrexate loaded vesicles on experimental periodontitis in mice. Methods: Extracellular vesicles (EVs) were isolated from human umbilical cord mesenchymal stem cells (hUC-MSC). Methotrexate loaded vesicles (MTX-EVs) were constructed, whose morphology and size were analyzed by using scanning electron microscopy and particle size analyzer. Western blotting was used to identify their surface specific proteins. C57BL/6J male mice of 4-5 weeks (provided by Experimental Animal Center of The Fourth Military Medical University) were selected, among which 8 were randomly selected by blind grasp method without treatment and fed normally as normal group, and others were induced to periodontitis models by local injection of lipopolysaccharide (LPS) into the periodontium. The LPS was injected once every day with a concentration of 2 g/L and a volume of 5 μl, lasting for two weeks. The mice with successfully induced periodontitis were randomly divided into 4 groups by blind grasping method, with 8 mice in each group. The LPS group was with no treatment, and the other three groups were treated with periodontal local injection of MTX, EVs or MTX-EVs, respectively. Two weeks later, enzyme-linked immunosorbent assay (ELISA) was used to detect the expressions of inflammatory cytokine interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in gingival tissue. The amount of alveolar bone resorption of four groups was detected by using micro-CT scanning and HE staining. The expression proportion of the inflammatory factor in gingival tissue was analyzed by using flow cytometry. Results: The scanning electron microscopy results showed that EVs and MTX-EVs were circular or elliptical in shape. Dynamic light scattering (DLS) particle size analysis showed that the particle size of EVs was around 200 nm, while that of MTX-EVs was around 300 nm. The ELISA results showed IL-1β levels in the normal group, LPS group, LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group were (28.86±2.76), (51.50±2.04), (35.26±2.40), (45.49±2.04) and (35.77±3.49) ng/L. That is, the IL-1β concentrations in the LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group were significantly lower than that in the LPS group (P<0.05); the mass concentration of IL-1β in the LPS +MTX-EVs group was significantly lower than that in the LPS+EVs group (P<0.05). The concentrations of IL-6 in the normal group, LPS group, LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group were (125.44±4.12), (221.64±10.59), (178.16±16.90), (181.09±18.22) and (170.15±9.04) ng/L, among which the concentration of IL-6 in the last three groups were significantly lower than that in the LPS group (P<0.05). The mass concentration of IL-6 in the LPS+MTX-EVs group was significantly lower than those in the LPS+MTX group and LPS+EVs group (P<0.05). The concentrations of TNF-α in the normal group, LPS group, LPS+MTX group, LPS+EVs grou

Objective: Explore the expression pattern of transcription factor activator protein 2C (TFAP2C) and identify the roles of Tfap2c during tooth development. Methods: Real-time fluorescence quantitative PCR (RT-qPCR) was used to analyze the relative expression level of Tfap2c in various organs of embryonic day(E)14.5 mouse embryos and mouse molar germs at E12.5-E18.5 and postnatal day (P)0-P7. The expression position of Tfap2c in mouse molar germs was demonstrated by frozen section immunofluorescence staining. Cultured mandibular molar germs were transfected with control small interfering RNA (siRNA) or Tfap2c siRNA to evaluate the effect of Tfap2c on tooth molar germs development, and RT-qPCR was used to detect the relative expression level of genes related to odontoblast expression. Dental mesenchymal cells were isolated from E14.5 molar germs and transfected with control siRNA or Tfap2c siRNA, cell counting kit 8 (CCK-8) and scratch healing test were applied to detect dental mesenchymal cell viability and migration. Results: Tfap2c was highly expressed in the early development period of mouse molar germs. Tfap2c was expressed in the epithelial and mesenchymal tissues of E13.5 mouse molar germs and there was no significant difference of relative expression of Tfap2c between them (t=1.06, P=0.472). Tfap2c was expressed in mesenchymal tissues of E14.5 mouse molar germs and the relative expression of Tfap2c in mesenchymal tissues was significantly higher than epithelial tissues (t=37.29, P<0.0001). For molar germs transfected with Tfap2c siRNA, the relative height of cusps (0.708±0.171) and the ratio of cusp height and crown height (0.321±0.068) was significantly lower than control group (1.000±0.287 and 0.483±0.166) (t=2.79, P=0.012; t=2.85, P=0.015). But there was no significant difference in relative height (1.078±0.206, 0.993±0.254, t=0.83, P=0.419)and relative width (1.000±0.116, 0.999±0.122, t=0.01, P=0.992) of crowns between two groups. The relative expression level of genes related to odontoblast expression was decreased (Dspp: t=15.33, P<0.001; Dmp1: t=13.81, P<0.001). Tfap2c siRNA hinders cell migration in dental mesenchymal cells (t=29.86, P=0.001), but there was no significant difference in CCK-8 absorbance value between two groups. The relative expression level of genes related to odontoblast expression was also decreased in dental mesenchymal cells transfected with Tfap2c siRNA (Dspp: t=3.86, P=0.031; Dmp1; t=4.36, P=0.022). Conclusions: Tfap2c highly expressed in the early morphogenesis period of mouse molar germs, mainly in mesenchymal tissues. Tfap2c affected the cusps formation of mouse molar germs and migration of dental mesenchymal cells.

Congenital tooth agenesis is a type of craniofacial developmental anomaly with reduced number of teeth, which is caused by disturbances in tooth germ development. If the number of missing teeth is less than six (excluding the third molars), it is termed as hypodontia. The second premolars are most commonly affected. When the second premolars are missing, the second primary molars are more prone to suffer from retention, infraocclusion, caries, pulpitis, or periapical periodontitis. Without timely prevention and appropriate treatment, congenital loss of second premolars may cause adverse effects on the patients' tooth arrangement, occlusal function, craniofacial development, and even future prosthetic treatment. This review summarises the aetiological and diagnostic features of the agenesis of second premolars, and discusses the clinical considerations of retaining or extracting the second primary molars without permanent tooth germs, when the absence of permanent tooth germs is fully established or not, so as to provide references for dentists.