Histamine deficiency deteriorates LPS-induced periodontal diseases in a murine model via NLRP3/Caspase-1 pathway.

Histamine is a versatile biogenic amine, generated by the unique enzyme histidine decarboxylase (Hdc). Accumulating evidence has proven that histamine plays important roles in numerous biological and pathophysiological processes. However, the role and mechanism of Hdc/Histamine signaling in periodontal diseases remain unclear. In our current study, the concentration of histamine increased in the serum, and Hdc gene expression was upregulated in the gingiva of WT mice with LPS-induced periodontal inflammation. With Hdc-GFP mice, we identified that Hdc/GFP in the periodontium was expressed in CD11b+ myeloid cells, rather than in tryptase-positive mast cells. Hdc-expressing CD11b+Gr-1+ neutrophils significantly increased in the peripheral blood of Hdc-GFP mice one day after LPS injection. Lack of histamine in Hdc-/- mice not only promoted the activation and infiltration of more CD11b+ cells into the peripheral blood but also upregulated mRNA expression levels of IL-1ß, IL-6, MCP-1and MMP9 in the gingiva compared to WT mice one day after LPS stimulation. 28 days after LPS treatment, we observed that Hdc-/- mice exhibited more alveolar bone loss and more osteoclasts than WT mice, which was slightly ameliorated by the administration of exogenous histamine. In vivo and in vitro mechanistic studies revealed that the mRNA expression levels of proinflammatory cytokines and protein levels of NLRP3, Caspase-1, and cleaved-Caspase-1 were upregulated after blocking histamine receptor 1 and 2, especially histamine receptor 1. Taken together, CD11b+Gr-1+ neutrophils are the predominant Hdc-expressing sites in periodontal inflammation, and deficiency of endogenous histamine in Hdc-/- mice exacerbates the destruction of the periodontium. Disruption of the histamine/H1R/H2R axis aggravates the inflammatory immune response via NLRP3/Casapse-1 pathway.

Problem-based learning and case-based learning in dental education.

BACKGROUND: Numerous novel teaching methods have been developed in recent times for use in medical education. Of these methods, problem-based learning (PBL) and case-based learning (CBL) have attracted the most attention. We evaluated and compared the efficiency of these two teaching methods in dental education and discussed the importance of teachers to these courses. This study aims to evaluate the efficiency of PBL and CBL in dental education, and discuss the importance of teachers to the courses. METHODS: In this study, 28 students enrolled in a seven-year program at the College of Stomatology at Shanghai Jiao Tong University were chosen as participants. In the fourth year, PBL combined with independent learning was used to teach students the theory of oral mucosal diseases. During the internship, CBL was used to present specific cases. Both methods were carried out with group discussion. After the PBL course, teachers assessed its effect by the students' class performance, their ability to collect data, and group cooperation. After the CBL course, its effect was assessed by the students' ability in history-taking, diagnosis and antidiastole, and case analysis. In addition, the teachers' roles in both methods were assessed by both the students and the teachers themselves. Data was collected by questionnaire survey and statistically analyzed with SPSS Statistics 20. RESULTS: PBL significantly improved students' self-learning abilities in the theory course. CBL helped students make diagnoses and develop treatment plans for actual cases in the internship. Both students and teachers thought that teachers were indispensable to both PBL and CBL. There was no difference between student and teacher views. CONCLUSIONS: Although PBL and CBL have different focuses, their combination may enhance teaching effectiveness in dental education. Additionally, teachers play an important role in the application of both these teaching methods.

Short versus longer implants with osteotome sinus floor elevation for moderately atrophic posterior maxillae: A 1-year randomized clinical trial.

PURPOSE: To compare the clinical, radiographic outcomes and patient satisfaction of short-6-mm implants and longer implants combined with osteotome sinus floor elevation (OSFE). MATERIALS AND METHODS: Two hundred and twenty-five patients with 225 implants were included and randomly assigned into three groups (each group: 75 implants) using randomizing table method: group 6 mm (6 mm implants alone), group 8 mm + O (8 mm implants + OSFE) and group 10 mm + O (10 mm implants + OSFE). Outcomes measures were as follows: implant survival, complication, resonance frequency analysis measurement, surgical time, bleeding on probing (BOP), pocket probing depth (PPD), modified plaque index (mPI), marginal bone loss (MBL) and patient satisfaction. RESULTS: The dropout rate was 3.6% at 1 year. Implant survival rates were 96%, 100% and 100% in group 6 mm, group 8 mm + O and group 10 mm + O, respectively. In group 6 mm, the survival rates of implants with diameter of 4.1 mm were 90% (27/30), while the survival rates of implants with diameter of 4.8 mm were 100% (42/42). The surgical time (min) in group 6 mm was significantly shorter than those in group 8 mm + O and group 10 mm + O (13.6 ± 2.2, 19.4 ± 3.7 and 18.3 ± 4.3, respectively, p = 0.03). No significant differences in ISQ values, BOP, PPD, mPI and MBL were found among three groups. Significant higher value of intra-operative discomfort was found in group 6 mm (p = 0.02). CONCLUSION: All treatment options provided acceptable clinical and radiographic results up to 1 year after loading. The current 1-year results must be confirmed by longer follow-ups of at least 5 years.

Do lncRNAs and circRNAs expression profiles influence discoid lupus erythematosus progression?-a comprehensive analysis.

BACKGROUND: Long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs)are involved in the progression of discoid lupus erythematosus (DLE), but an understanding of their underlying mechanisms remains elusive. To explore the expression profiles of lncRNAs and circRNAs in DLE, we surveyed the lncRNA/circRNA and mRNA expression profiles in the epithelia of oral DLE and adjacent normal tissues. METHODS: The lesional and non-lesional lower lips of three DLE patients were analysed by RNA-sequencing (RNA-seq). The principal functions of the significantly deregulated genes were identified using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. And the correlated expression networks (coding-noncoding co-expression and lncRNAs-transcription factor-mRNA) were evaluated as well. RESULTS: Hundreds of significantly changed lncRNAs and mRNAs and dozens of significantly changed circRNAs were identified. lncRNA lnc-MIPOL1-6 and IncRNA IncDDX47-3 expressions were correlated with immune response-related genes, including IL19, CXCL1, CXCL11, and TNFSF15. Up-regulated IncRNA-TF network consists of 8 TFs and 74 related lncRNAs. The lncRNA-TF-gene trans-regulation consisting of 204 lncRNAs,39 TFs, and correlated 3 genes. CONCLUSIONS: These results demonstrate that lncRNAs and circRNAs can influence the progression of DLE. Certain mRNAs/lncRNAs/circRNAs may have substantial value in DLE diagnosis and therapy.

Functionalized epigallocatechin gallate copolymer inhibit dentin matrices degradation: Mechanical, solubilized telopeptide and proteomic assays.

OBJECTIVES: We investigated the biostability of dentin organic matrices treated with epigallocatechin gallate (EGCG) in comparison to chlorhexidine (CHX), both extracted from functionalized copolymers. METHODS: Copolymers were prepared with bis-GMA:TEGDMA and incorporated with 1% of EGCG or CHX (w/w). Blank copolymers were used as control. Copolymer samples were individually stored in 1mL deionized water to produce copolymer extracts. Dentin matrices were obtained by demineralization of dentin disks in 10% phosphoric acid solution. Matrices were individually treated with 1mL of the copolymer extracts or distilled water for 48h. Collected extracts were analyzed by high-performance liquid chromatography (HPLC) for the presence and quantification of EGCG, CHX, and copolymer by-products. Treated dentin matrices were tested for ultimate tensile strength, gravimetric changes, and swelling ratio. The treatment media were tested for total protein concentration, and dentin protease activity through solubilized telopeptide (ICTP- and CTX-ELISA) assays. The treatment media were also submitted to proteomic analysis. RESULTS: HPLC identified released unreacted copolymer species and showed higher release of CHX compared to EGCG from respective copolymer extracts. EGCG extract inhibited activity of dentin proteolytic enzymes and promoted collagen biomodification observed by the telopeptide assays and in the changes to dentin matrix properties. The proteomic results showed less collagenous peptide hits in the EGCG extract media compared to CHX, and suggest compound-specific dentin protein binding interactions. SIGNIFICANCE: This study demonstrates specific antiproteolytic effect and protein interactions of EGCG copolymer extract directly on dentin. This represents an advancement in dental materials which can impact the clinical procedures.

Comparison of Adaptation between the Major Connectors Fabricated from Intraoral Digital Impressions and Extraoral Digital Impressions.

The objective was to compare the adaptation between the major connectors of removable partial dentures derived from intraoral digital impressions and extraoral digital impressions. Twenty-four volunteers were enrolled. Each volunteer received an intraoral digital impression and one extraoral digital impression digitized from conventional gypsum impression. A software was used to create the major connectors on digital impression datasets. After all the virtual major connectors designed from Group intraoral digital impressions (Group I) and Group extraoral digital impressions (Group E) were directly fabricated by 3D printing technique, the adaptation of the final major connectors in volunteers' mouths were measured. The adaptation ranged from 159.87 to 577.99 µm in Group I while from 120.83 to 536.17 µm in Group E. The adaptation of major connectors in Group I were found better at the midline palatine suture while the adaptation of major connectors in Group E were found better at the two sides of the palatal vault. In both groups, the highest accuracy in adaptation was revealed at the anterior margin of the major connectors. It is feasible to manufacture the major connectors by digital impression and 3D printing technique. Both the adaptation of the two kinds of digital impressions were clinical acceptable.

Accuracy of Intraoral Digital Impressions for Whole Upper Jaws, Including Full Dentitions and Palatal Soft Tissues.

Intraoral digital impressions have been stated to meet the clinical requirements for some teeth-supported restorations, though fewer evidences were proposed for larger scanning range. The aim of this study was to compare the accuracy (trueness and precision) of intraoral digital impressions for whole upper jaws, including the full dentitions and palatal soft tissues, as well as to determine the effect of different palatal vault height or arch width on accuracy of intraoral digital impressions. Thirty-two volunteers were divided into three groups according to the palatal vault height or arch width. Each volunteer received three scans with TRIOS intraoral scanner and one conventional impression of whole upper jaw. Three-dimensional (3D) images digitized from conventional gypsum casts by a laboratory scanner were chose as the reference models. All datasets were imported to a specific software program for 3D analysis by "best fit alignment" and "3D compare" process. Color-coded deviation maps showed qualitative visualization of the deviations. For the digital impressions for palatal soft tissues, trueness was (130.54±33.95)µm and precision was (55.26±11.21)µm. For the digital impressions for upper full dentitions, trueness was (80.01±17.78)µm and precision was (59.52±11.29)µm. Larger deviations were found between intraoral digital impressions and conventional impressions in the areas of palatal soft tissues than that in the areas of full dentitions (p<0.001). Precision of digital impressions for palatal soft tissues was slightly better than that for full dentitions (p = 0.049). There was no significant effect of palatal vault height on accuracy of digital impressions for palatal soft tissues (p>0.05), but arch width was found to have a significant effect on precision of intraoral digital impressions for full dentitions (p = 0.016). A linear correlation was found between arch width and precision of digital impressions for whole upper jaws (r = 0.326, p = 0.034 for palatal soft tissues and r = 0.485, p = 0.002 for full dentitions). It was feasible to use the intraoral scanner to obtain digital impressions for whole upper jaws. Wider dental arch contributed to lower precision of an intraoral digital impression. It should be confirmed in further studies that whether accuracy of digital impressions for whole upper jaws is clinically acceptable.

Anthocyanin incorporated dental copolymer: bacterial growth inhibition, mechanical properties, and compound release rates and stability by (1)h NMR.

Objective. To evaluate bacterial growth inhibition, mechanical properties, and compound release rate and stability of copolymers incorporated with anthocyanin (ACY; Vaccinium macrocarpon). Methods. Resin samples were prepared (Bis-GMA/TEGDMA at 70/30 mol%) and incorporated with 2 w/w% of either ACY or chlorhexidine (CHX), except for the control group. Samples were individually immersed in a bacterial culture (Streptococcus mutans) for 24 h. Cell viability (n = 3) was assessed by counting the number of colony forming units on replica agar plates. Flexural strength (FS) and elastic modulus (E) were tested on a universal testing machine (n = 8). Compound release and chemical stability were evaluated by UV spectrophotometry and (1)H NMR (n = 3). Data were analyzed by one-way ANOVA and Tukey's test ( α = 0.05). Results. Both compounds inhibited S. mutans growth, with CHX being most effective (P < 0.05). Control resin had the lowest FS and E values, followed by ACY and CHX, with statistical difference between control and CHX groups for both mechanical properties (P < 0.05). The 24 h compound release rates were ACY: 1.33 µg/mL and CHX: 1.92 µg/mL. (1)H NMR spectra suggests that both compounds remained stable after being released in water. Conclusion. The present findings indicate that anthocyanins might be used as a natural antibacterial agent in resin based materials.

Fabrication of porous titanium implants by three-dimensional printing and sintering at different temperatures.

This study evaluated the feasibility of using three-dimensional printing (3DP) to fabricate porous titanium implants. Titanium powder was blended with a water-soluble binder material. Green, porous, titanium implants fabricated by 3DP were sintered under protective argon atmosphere at 1,200, 1,300, or 1,400°C. Sintered implant prototypes had uniform shrinkage and no obvious shape distortion after sintering. Evaluation of their mechanical properties revealed that titanium prototypes sintered at different temperatures had elastic modulus of 5.9-34.8 GPa, porosity of 41.06-65.01%, hardness of 115.2-182.8 VHN, and compressive strength of 81.3-218.6 MPa. There were significant differences in each type of these data among the different sintering temperatures (p<0.01). Results of this study confirmed the feasibility of fabricating porous titanium implants by 3DP: pore size and pore interconnectivity were conducive to bone cell ingrowth for implant stabilization, and the mechanical properties matched well with those of the human bone.

[Studies on personalized porous titanium implant fabricated using three-dimensional printing forming technique].

Three-dimensional printing (3DP) forming technology can shape personalized porous implant material with complex shape and fine structure to meet the various needs of different patients. In this paper, the green parts of porous titanium implants with diameter 25 mm x 20 mm were prepared using 3DP, and then debinded at 500 degrees C under vacuum. Finally they were sintered in the argon gas at 1 300 degrees C. The pore sizes were observed, and they were between 50-150 microm under SEM. The results of porosity, bulk density, Vickers hardness, compressive strength and elastic modulus were (44.26% +/- 2.43)%, (2.59 +/- 0.81)g/cm3, 134.2-151.6 (61.2 +/- 3.2) MPa, (3.25 +/- 1.08) GPa, respectively. That shows excellent biomechanical compatibility. It is concluded that 3DP has wide application for fabrication of personalized porous titanium implant.

Nasal prosthesis rehabilitation using CAD-CAM technology after total rhinectomy: a pilot study.

PURPOSE: This study describes a nose prosthetic rehabilitation using computer-aided design and manufacturing (CAD-CAM) technology after facial disfigurement because of a total rhinectomy. METHODS: A patient with a total rhinectomy was scheduled for a nasal prosthesis. Based on the 3-D model of the patient's face reconstructed with the CT data, a four-piece mould for the nasal prosthesis was prototyped using a CAD-CAM procedure. Conventional silicone was processed with this physical mould to fabricate the definitive nasal prosthesis. RESULTS: A silicone nasal prosthesis was manufactured. The size, shape, and cosmetic look of the prosthesis were satisfactory and matched the nasal defect area well. CONCLUSIONS: The protocol presented herein illustrates favorable clinical treatment outcomes in the prosthetic rehabilitation after a total rhinectomy by means of CAD-CAM technology.

[Digital diagnosis and treatment system for facial prostheses].

Conventional diagnosis and treatment for facial prostheses have setbacks and limitations, including complicated procedure, inefficiency, low accuracy and poor esthetics, which could not meet the demand for high quality of the prostheses of the patients. With the technology of the computer aided design and computer aided manufacture (CAD/CAM), the new era for diagnosis and treatment for facial prostheses has been started since the 1990's. The digital diagnosis and treatment system for facial prostheses has been formed during these ten years, which including the digital data acquisition of the facial defect, CAD for facial prostheses, rapid fabrication of the prostheses. This new system will be the development direction and mainstream technology in the future.

[A preliminary study on maxillofacial prosthesis using structured light three-dimensional scanning and rapid prototyping technique].

OBJECTIVE: To evaluate application of three-dimensional reconstruction of the facial soft tissue by use of light three-dimensional scanning system and rapid prototyping and to lay a foundation for developing the computer aided design (CAD) and computer aided manufacture (CAM) system of the maxillofacial defect rehabilitation. METHODS: The left and right facial profiles of a volunteer were scanned with the light three-dimensional scanning system that was a self-developed one. The complete point and cloud data were obtained by transforming the image data with the Surfcaq software. Then three-dimensional reconstruction was done via transforming the point and cloud data to Geomagic studio 7.0. The final three-dimensional reconstruction was achieved by way of putting the point and cloud data together with apex nasi, external point of the orbit, mention as the mark points. The image was imported into Magics RP to triangulate and created in the thickness of 2 mm. The three-dimensional resin model was fabricated by fused deposition modeling (FDM). RESULTS: The three-dimensional image of the facial soft tissue of the volunteer was achieved. The three-dimensional resin model of the facial soft tissue of the volunteer was also obtained. CONCLUSIONS: Light three-dimensional scanning system was feasible for three-dimensional reconstruction.

[A preliminary study on facial profile reconstruction using structured light three-dimensional scanning technique].

OBJECTIVE: To evaluate the feasibility of facial profile reconstruction by use of structured light three-dimensional scanning technique. METHODS: Based on Gray-code and phase-shifting method, the self-developed three-dimensional optical measurement system was used to acquire the primitive point data of a volunteer's face and cast of the face. All the datum records were processed and analysed with Imageware and Geomagic software to reconstruct a three-dimensional face model. RESULTS: Compared with the conventional impression method, the structured light three-dimensional scanning technique reconstructed facial profile with smaller deformation. CONCLUSIONS: Based on Gray-code and phase-shifting method, the self-developed optical measurement system captured three-dimensional facial profile accurately. It would be helpful to the three-dimensional reconstruction of the facial profile defect.

[The role of the mouthguard in preventing sports-related oral-facial and dental traumas.].

Sports play a significant role in all nations worldwide. More and more people involve in sports so that the incidence of the oral-facial and dental traumas with accidents ascends. The treatment cost is considerable, and the sporters' lives will be influenced by these traumas. This paper examines the status and the reasons of the oral-facial and dental traumas. It reviews not only the principle and the types of the mouthguard but also the evidence of the mouthguard in preventing sports-related traumas. Prevention is thought to be the key element in minimizing traumas that occur in sports, the using of mouthguard is considered essential.