Inflammatory bowel disease (IBD) is a group of chronic, non-specific inflammatory diseases of the gastrointestinal tract including primarily Crohn’s disease and ulcerative colitis, which are affected by multiple factors. Periodontitis is a type of disease characterized by plaque biofilm as the initiating factor and chronic destruction of alveolar bone via resorption. An increasing number of studies have reported a correlation between periodontitis and IBD, but the relationship between the two remains unclear. In this study, we explore the internal relationships between the two diseases from three dimensions, including epidemiological, biological, and associated treatment evidence. Based on epidemiological evidence, periodontitis was found to be associated with an increased risk of IBD, which also affects periodontal health, although the bidirectional correlation needs to be further studied by expanding the number of data sources. From the biological evidence, both clinical studies and animal experiments show that IBD and periodontitis are interconnected. Based on evidence from association therapy, drugs that are beneficial for the treatment of IBD are also effective in the prevention and treatment of periodontitis. In addition, drugs that are good for improving periodontitis can also significantly alleviate IBD. The interaction mechanism between IBD and periodontitis includes the microbial pathway and the immunization route. The microbial pathway refers to the increase in the probability of intestinal tract ectopic colonization by oral bacteria transmitted through the mouth-gut axis or blood, resulting from the increase in the proportion of opportunistic pathogens in the oral cavity of patients with periodontitis and the influence of IBD on the secretion of gastric juice and the balance of intestinal flora. These microorganisms further aggravate IBD inflammation by releasing virulence factors, destroying the intestinal mucosal barrier, and triggering inflammatory responses. In periodontitis, adaptive immunity is activated in the mouth, leading to the production of a large number of immune cells, including Th17 containing the intestinal homing marker α4β7 integrin on their surface. Increased ligand expression of α4β7 integrin in the intestinal mucosa of patients with IBD accelerates oral Th17 cell transfer to the intestine, thereby worsening intestinal inflammation. In parallel, the abnormal expression of cytokines, such as TNF-α, IL-1β, IL-10, IL-6, IL-21, soluble CD40 ligand (sCD40L), IL-23, and INF-γ, in the oral cavity of patients with IBD was observed, suggesting that IBD may affect periodontitis through immunity. These cytokines represent targets for the treatment of both diseases and provide a research direction for their prevention and treatment in the future.

Bacterial overproliferation and virulence factors in plaque biofilms can cause inflammation of soft and hard tissues around the implant, resulting in peri-implantitis. If not well controlled, severe peri-implantitis can lead to failure of implant osseointegration and implant loosening and loss. Currently, peri-implantitis can be treated by surgical and non-surgical treatment such as mechanical debridement and chemotherapy, but there remain problems related to the unpredictable therapeutic effect and high recurrence rate. Therefore, gaining a comprehensive understanding of the relationship between plaque biofilm formation and peri-implantitis is crucial for the prevention and treatment of peri-implantitis. In this article, we comprehensively review current research on the specific composition and formation process of biofilms and the influence of implant material characteristics on biofilm formation. The results of the research review indicated that peri-implantitis biofilms are composed of extracellular matrix, with a predominant population of anaerobic Gram-negative bacteria embedded within. The formation process includes the acquisition of an acquired membrane, microbial adhesion, and biofilm detachment and dispersion. Biofilm formation is primarily influenced by the implant surface roughness, surface free energy (SFE), and material properties. Current strategies for biofilm removal around implants mainly involve implant surface coating techniques, mechanical debridement, chemical agents, laser therapy, and photodynamic therapy; however, the therapeutic outcomes remain uncertain. The future research direction will be based on the characteristics of the plaque biofilm around the implant, combined with cutting-edge methods, such as nanotechnology, immunotherapy, and gene therapy, to continuously prevent the formation of plaque biofilm on the surface of the implant to prevent and treat peri-implantitis.

Chronic kidney disease is a global public health problem threatening human health and affects the function of multiple organ systems. The oral health of patients is often affected as the disease progresses. Dental implants have become the best way to repair tooth loss. It is necessary and challenging to provide safe and reliable dental implant treatment for patients with chronic kidney disease. Dental clinicians should evaluate the health of patients comprehensively, complete blood biochemistry, coagulation function, and imaging examinations, and provide feasible, reliable and personalized treatment plans. During the treatment phase, dental clinicians need to consider prophylactic antibiotics, painless minimally invasive surgery, infection control, and delayed restoration, and they must cooperate with other clinicians in multiple disciplines to reduce risks to provide personalized, safe, and effective oral implant treatment for patients with chronic kidney disease.

Objective: To study the effects of different concentrated sulfuric acid etching durations on the shear bond strength between polyether-ketone-ketone (PEKK) and dentin, providing a scientific basis for the clinical bonding procedures of PEKK prosthesis. Methods: Forty-four PEKK specimens were prepared and randomly divided into four groups: group A was the control group, which was only polished with abrasive papers, group B, group C and group D were experimental groups, which were etched by 98% concentrated sulfuric acid for 5 s, 30 s and 60 s, respectively. In addition, one sample was randomly selected from each group, and the profile was prepared by a slow cutting machine. The surface morphology of the profile was observed under SEM. After the four groups of specimens and dentin were bonded by resin, they were soaked in distilled water at 37 ℃ for 24 h. After the shear bonding strengths were measured, the fracture interfaces of the specimens were examined by the scanning electron microscopy and stereomicroscopy, and failure models of bonding were analyzed. Results: After acid etching treatments, the cross-sectional images in group B presented uniform spongy shapes, while the cross-sectional images in group C and group D showed destructive pore structures. The shear bond strengths of group B (16.84 ± 1.84) MPa, group C (12.33 ± 1.22) MPa and group D (6.44 ± 1.18) MPa were higher than that of group A (3.99 ± 1.06) MPa (P < 0.05). The highest shear bond strength was observed in group B (16.84 ± 1.84) MPa. Conclusion The surface treatment of 98% sulfuric acid etching for 5 s manifested the best bond strength between PEKK and dentin.

Objective : To detect the composition of the subgingival microbiota in generalized aggressive periodontitis (GAgP) and severe chronic periodontitis (SCP) patients tested by high-throughput sequencing (HTS) technologies, analyze its diversity and function by using bioinformatics, and observe changes in the subgingival microbiota before and after periodontal initial therapy. Methods: Eleven patients with GAgP and 14 patients with SCP who visited the Department of Periodontics in Stomatological Hospital of Kunming Medical University from September 2018 to May 2019 were recruited, and subgingival plaque samples were collected at baseline and 6 weeks after initial therapy. Then, the genomic DNA was distracted and sequenced by the Illumina MiSeq high-throughput sequencing platform. QIIME (quantitative insights in microbial ecology), Mothur, SPSS and other software were used to analyze community information. LEfSe difference analysis (linear discriminant analysis effect size), network analysis, and the KEGG PATHWAY database (https://www.kegg.jp/kegg/pathway.html) were used to predict community function. Results : At baseline, the dominant microbiota of GAgP and SCP patients were similar, including Bacteroidetes, Porphyromonas and Porphyromonas endodontalis. Six weeks after initial therapy, as the periodontal pocket became shallower, the variation trend of the microbiota of GAgP and SCP patients was similar. The relative abundance of gram-negative bacteria, such as Bacteroidetes, Porphyromonas and Porphyromonas endodontalis, decreased, while the relative abundance of gram-positive bacteria, such as Proteobacteria, Actinomyces and Rothia aeria, increased. Actinobacteria were significantly increased biomarkers of the subgingival microbiota in GAgP after treatment. Streptococcus is an important genus that connects the microbiota related to periodontitis and the microbiota related to periodontal health. Community function prediction result showed that initial treatment can reduce the functions of amino acid metabolism, methane metabolism, and peptidase in GAgP and SCP patients. Conclusion The subgingival microbiota of GAgP and SCP patients are similar. Streptococcus, as an early colonizer, may play an important role in promoting plaque biofilm formation and maturation in the process of subgingival flora from health to imbalance. Initial therapy can change the composition and structure of the subgingival microbiota, reduce community diversity, and reduce the functions of amino acid metabolism, methane metabolism, and peptidase in GAgP and SCP patients.

Objective: To compare the stress distribution of different all-ceramic restoration materials and thicknesses in dental crown restorations using the finite element method and provide a reference for the selection and design of clinical crown restoration materials. Methods: A finite element model of mandibular first molar implant crown restoration was created, and 6 crown thickness designs and 4 different crown restoration materials were evaluated, namely, resin-based ceramics (Lava Ultimate and Vita Enamic), lithium disilicate glass-ceramics (IPS e.max CAD), and zirconia ceramic (Cercon) designs. The mandibular first molars were loaded at 600 N, and the stress distribution was analyzed by using the finite element software ANSYS 10.0. Results: The crown stress analysis showed that 156.05 MPa was the highest in 4 mm Cercon group and 18.85 MPa was the lowest in 1 mm Lava Ultimate group. The stress analysis of resin cement showed that 62.52 MPa was the highest in the 4 mm Lava Ultimate group and 16.74 MPa was the lowest in 1 mm IPS e.max CAD group. During the use of the finished platform, the stress concentration of the Lava Ultimate group in the crown prosthesis and resin cement was higher than that of the personalized platform with the same crown thickness. Conclusion With increasing crown thickness, the maximum principal stress concentration in crown restoration and resin cement increases. Personalized abutments are more conducive to reducing stress concentrations for resin-based ceramics.

Objective : To investigate the clinical effect of periodontal endoscope-assisted scaling and root planing (SRP) in treating advanced periodontitis. Methods: Nineteen cases of grade Ⅲ and Ⅳ periodontitis selected from June 2017 to January 2019 in the Nanjing Stomatological Hospital, Medical School of Nanjing University were divided into the periodontal endoscope and control groups. In the periodontal endoscope group, SRP was performed under a periodontal microscope in one treatment after initial supragingival scaling; in the control group, SRP was performed under regular conditions, and additional SRP was conducted in positive bleeding on probing sites twice every other week as needed. Periodontal status, including probing depth (PD), bleeding on probing (BOP) and attachment loss (AL), was recorded by a Florida probe. Results: For sites of 40.05). There was no significant difference in the BOP positive rate or AL change between the two groups at 3 months and 6 months (P > 0.05). For sites with PD > 6 mm, at baseline, the positive rates of PD, BOP and AL in the endoscope group were more serious than those in the control group, and the differences were statistically significant. The PD- and BOP-positive rates and AL in the endoscope group and control group decreased significantly from baseline at 3 and 6 months. However, PD in the endoscope group became shallower than that in the control group (P < 0.05) after 3 and 6 months. There was no significant difference in the BOP positive rate or AL between the two groups (P>0.05). Conclusion When compared to regular SRP, periodontal microscope-assisted SRP achieves better improvement in PD and is more beneficial for reducing the BOP and AL of deeper sites.

Objective : To compare the accuracies of implants with dynamic real-time navigation versus digital guide navigation to provide a reference for clinical precision dental implants. Methods: Forty-six cases (seventy teeth) with missing teeth admitted to the Department of Stomatology, Wuzhou Red Cross Hospital from April 2018 to December 2019 were randomly divided into two groups (thirty-five teeth in each group) for dynamic real-time navigation and digital guide navigation implantation techniques. To compare the entry point, apex point, depth and angle deviation of the preoperative and postoperative position of implants in the two groups. SPSS 21.0 software was used for statistical analysis. Results : Dental implants were successfully placed in both groups. The deviations of apex point, depth and angle in the dynamic real-time navigation group were all smaller than those in the digital guide navigation group, and the differences were statistically significant (P < 0.05). There was no statistically significant deviation in the entry point between the two groups (P > 0.05). Conclusion In this study, both techniques had good clinical effects. The accuracy of dynamic real-time navigation was higher than that of digital guidance.

The Streptococcus mutans (S. mutans) phage, as one of the principal pathogenic bacteria of dental caries, is a main cause of the formation and development of dental caries due to its overproliferation in dental plaque biofilms. Bacterial viruses, also known as bacteriophages, have the capability of specifically infecting bacteria and effectively degrading bacterial biofilms. S. mutans phages, therefore, may prevent and control caries. Therapy based on phages has been applied in many fields, but the application of S. mutans phages in caries remains exploratory. This article will review the research progress of S. mutans phages in clinical caries prevention, aiming to provide a new idea for the clinical prevention of caries. The results of the literature review show that the living bacteriophage system has the advantages of high specificity, high affinity and good safety. However, due to its unstable structure, it can be processed into a more stable formulation by freeze-drying, spray drying, adding stability enhancers, or incorporating bacteriophages into ointments, biodegradable polymer matrices or particles to a certain extent to improve stability. The lysozyme produced by phages can digest the bacterial cell wall and release the assembled phage particles, which effectively cleave biofilms. In addition, the antigen binding fragment library for cariogenic pathogens was screened by phage display technology, and the purpose of caries prevention and treatment was achieved by passive immunization of antigen binding fragments. However, the host range of bacteriophages is narrow, so this kind of problem can be overcome by phage combined with traditional therapy or other drug use or cocktail therapy with multiple phages in clinical caries prevention and control.

Cyclophilin A (CypA) is the first foldable enzyme in human cells that has peptidyl proliferase-trans isomerase activity and has a strong proinflammatory effect. CD147 can act as the signal receptor of CypA. The interaction of the two through cell-surface heparin binding activates extracellular regulated protein kinases (ERK1/2) and nuclear factor kappa-B (NF-κB) signaling pathways in macrophages and increases the expression of MMPs and other inflammatory factors. The CypA/CD147 interaction regulates inflammation, promotes the inflammatory response and bone resorption and is involved in the pathological processes of a variety of systemic diseases. CypA and CD147 may take part in the chemotaxis of inflammatory cells, increase white blood cell infiltration in tissues, and increase CypA and CD147 expression in periodontitis gum tissue and gingival groove liquid with inflammation, prompting their interaction to promote the progression of periodontitis. However, the specific function of the signaling pathways in the periodontitis mechanism still requires further elucidation.