[Retrospective analysis of the effectiveness of treating multi-space infection combined with descending necrotizing mediastinitis at oral maxillofacial and cervical region via multidisciplinary team collaboration].

Objective: To explore the strategy and experience for treating maxillofacial and cervical multi-space infection combined with descending necrotizing mediastinitis (DNM) via multidisciplinary team (MDT) collaboration. Methods: A total of 36 patients with maxillofacial and cervical multi-space infection complicated with DNM admitted to the First Affiliated Hospital of Zhengzhou University from July 2011 to July 2019 were included in the study. The clinical data of the patients were retrospectively analyzed, including gender, age, symptoms at admission, source of infection, preoperative and postoperative evaluation indicators, MDT strategy and prognosis. Results: There were 26 males and 10 females with an average age of (51.6±17.6) years (8-80 years). The course of disease before admission was (8.9±8.4) days (2-30 days). All patients were admitted with maxillofacial and neck swelling and pain as the main complaints. Odontogenic infection accounted for 39% (14/36), throat floor swelling and pain accounted for 25% (9/36) and unknown maxillofacial swelling accounted for 36% (13/36). There were 28 cases receiving surgical treatment, 26 cases were cured and discharged (72%), 10 cases died (28%). In the patients treated with multidisciplinary therapy (mainly by surgery), the white blood cell count, neutrophil percentage, C-reactive protein and procalcitonin levels were significantly improved compared with those at admission at each observation time point after operation (P<0.05). The length of stay was positively correlated with the levels of C-reactive protein (r=0.545, P<0.05) and procalcitonin (r=0.504, P<0.05). The prognosis of patients treated with surgery (26/28) was better than that of patients without surgery (0/8) (P<0.01). Conclusions: The patients with maxillofacial and cervical multi-space infection combined with DNM might be in critical condition. The surgical based MDT strategy has an important impact on the prognosis of patients. White blood cell count and other inflammatory indicators monitoring can effectively observe the changes of the patient's condition.

[Preliminary study on the elimination of artifacts of five kinds of dental prosthetic materials by energy spectrum CT multi-material artifact reduction technology].

Objective: To investigate the effect of the multi-material artifact reduction (MMAR) algorithm of spectral CT in reducing the beam hardening artifacts in dental restoration material. Methods: Three-unit fixed bridge restorations were fabricated on the first to third molars in pig jaw. Gold alloy, zirconia, cobalt chromium alloy, nickel chromium alloy and pure titanium were used as materials for these fixed bridges. After restoration delivery, the pig jaw was scaned using energy spectrum CT machines. Images in regular 120 kVp scan mode were used as conventional group, and reconstructed single-energy horizontal images of 80, 90, 100, 110, 120, 130 and 140 keV in energy spectrum scanning mode were used as energy spectrum group, and reconstructed images applied MMAR technology in energy spectrum scanning mode were used as energy spectrum MMAR group. Each group was scanned 10 times to measure CT value and noise of muscles around dental prosthetic materials and adjacent non-artifact layers. Artifact index was calculated. Two radiologists scored the image quality of each group subjectively. Kruskal Wallis rank sum test was used to compare the difference of image noise, artifact index and subjective score among the control group and the best keV condition in the energy spectrum group and the energy spectrum MMAR group. Results: The image noise of energy spectrum group and energy spectrum MMAR group decreased gradually with the increase of single energy level. The artifact index of pure titanium restorations in conventional group, energy spectrum group and energy spectrum MMAR group were 71.0±8.0, 21.4±2.7 and 14.7±2.7 respectively, and these values were significantly lower than those of other materials in the same group (P<0.05). The subjective image quality scores in energy spectrum MMAR group were as follows: 3.0±0.2 for gold alloy, 4.3±0.5 for zirconia, 3.0±0.4 for cobalt chromium alloy, 3.1±0.4 for cobalt chromium alloy, and 4.6±0.5 for pure titanium. These scores were significantly smaller than those in the conventional group (P<0.05). There was no significant difference in noise between energy spectrum group and energy spectrum MMAR group (P>0.05), and the noise values in energy spectrum group and energy spectrum MMAR group were significantly lower than that in the conventional group (P<0.05). Conclusions: Artifacts of pure titanium is minimal. Energy spectrum CT combined with MMAR technology can effectively reduce the artifacts of gold, zirconia, cobalt-chromium alloy, nickel-titanium alloy and pure titanium. This technique can be used as an effective method to remove artifacts of dental prosthesis.

Layer-by-layer assembly of viral capsid for cell adhesion.

Cowpea mosaic virus (CPMV)-based thin films are biologically active for cell culture. Using layer-by-layer assembly of CPMV and poly(diallyldimethylammonium chloride), quantitatively scalable biomolecular surfaces were constructed, which were well characterized using quartz crystal microbalance, UV-vis and atomic force microscopy. The surface coverage of CPMV nanoparticles depended on the adsorption time and pH of the virus solution, with a greater amount of CPMV adsorption occurring near its isoelectric point. It was found that the adhesion and proliferation of NIH-3T3 fibroblasts can be controlled by the coverage of viral particles using this multilayer technique.

Regulatory interplay between NFIC and TGF-ß1 in apical papilla-derived stem cells.

While transforming growth factor-ß1 (TGF-ß1) can regulate odontoblast differentiation in tooth crown morphogenesis, its effects on cells including stem cells from the apical papilla (SCAPs) involved in root formation are unclear. Nuclear factor I-C (NFIC) has been implicated in the regulation of root development, and interplay with TGF-ß1 signaling has been reported in some cell types. We hypothesize that NFIC and TGF-ß1 are important to the behavior of SCAPs and that the interplay between these molecules controls the regulation of the odontogenic differentiation of SCAPs. TGF-ß1 inhibited the proliferation of SCAPs and their mineralization. Real-time polymerase chain-reaction (RT-PCR) and Western blot results showed that TGF-ß1 significantly decreased osteogenic/dentinogenic gene expression. The inhibition of TGF-ß/Smad signaling (SIS3) attenuated the suppressive effect of TGF-ß1 on SCAPs. Importantly, overexpression of NFIC antagonized the effects of TGF-ß1 on SCAPs, while knockdown of NFIC enhanced these effects, demonstrating a key regulatory role for NFIC in modulating TGF-ß1 signaling in SCAPs. We conclude that this interplay between NFIC and TGF-ß1 regulates SCAPs behavior and can determine the differentiation of these cells. These signaling interactions help inform the development of regenerative strategies aimed at root growth and development in immature teeth for endodontic treatment.

[The expression and distribution of Smad 2 in human tooth germ].

OBJECTIVE: To investigate the expression of Smad 2 gene in human tooth germ,and the possible function of Smad 2 during human tooth germ development. METHODS: Immunohistochemical staining on prepared specimens of different stages of developing human tooth germ. RESULTS: Smad 2 expression had specific temporal-spatial pattern during tooth germ development, which was similar to TGF-beta. CONCLUSION: The expression of Smad 2 gene in tooth germ was detected in different stages of human tooth germ. The results suggest that Smad 2, one of the intracellular downstream molecules of TGF-beta, and as an inductive signal mediating epithelial-mesenchymal interaction, may regulate the differentiation of ameloblast and odontoblast cells, and modulate dentinogenesis and amelogenesis.

[Studies on the influence of composite resin filling material (Command Ultra fine) on the dental pulp].

Studies on the influence of composite resin filling material on the dental pulp of human 1st premolar are reported in this thesis. An other experiment was carried out on rabbit with the left 1st molar in their lower jaw as subject and the right 1st molar in the lower jaw as a control. In both experiments with human and rabbit, routine operations were performed to prepare the cavities and filled with composite resin material. The human teeth were extracted 21 days afterwards and the rabbit teeth were extracted 7 days afterwards. Edema was found in the dental pulp of both human and rabbit teeth by pathologic examination and was accompanied by hemangiectasis and lymphaniectasis. There was also vacuolar degeneration in the odontoblasts. Some of these cells were reticulated and the of number of odontoblasts was fewer than in the control. Hemangiectasis was even more serious in the rabbit's teeth than those of human.

Detection of interleukin-8 in exudates from normal and inflamed human dental pulp tissues.

OBJECTIVE: The purpose of this study was to investigate the level of IL-8 in exudates clinically obtained from normal and inflamed human dental pulp tissues so as to reveal the possible relationship between IL-8 and pulpitis. METHODS: Samples of 2 microliters of pulpal exudate from each normal or clinically diagnosed as acute or chronic pulpitis teeth was obtained by filter paper strips and IL-8 level was measured by ELISA method. RESULTS: No IL-8 was detected in the samples from normal pulp, but significant amount of IL-8 appeared in inflamed pulp tissues, and the level of IL-8 in exudates of acute stage of pulpitis was higher than that of chronic stage (P < 0.01). CONCLUSIONS: This study demonstrates that IL-8 is produced and accumulated in pulp inflammation and may play a role in the occurrence and development of human pulpitis.

Mineralized nodule formation by human dental papilla cells in culture.

Human dental papilla cells were enzymatically separated from deciduous tooth germs of an 8-month-old embryo legally aborted. The second passage cells were cultured up to 35 days in 3 groups. The beta-GP group was cultured in the Dulbecco MEM containing ascorbic acid and beta-glycerophosphate supplemented with 15% fetal bovine serum. The Dex group was in the same medium, in addition containing dexamethasone. The control group contained none of the 3 chemicals. Mineralized nodules were formed after 15 days in the beta-GP and Dex groups. Only in the presence of ascorbic acid and organic phosphate did they mineralize. The addition of dexamethasone caused a significant increase in the number of nodules. By electron microscopy, the nodules contained needle-shaped crystals associated with a network of collagen fibrils. Calcium and phosphorus were detected by energy-dispersive X-ray microanalysis in the nodules. Furthermore, the crystalline material exhibited a pattern consistent with hydroxyapatite and dentin when examined by X-ray diffractometry. Cells showed high levels of alkaline phosphatase activity, which was increased 2-3 times in the presence of the 3 chemicals. These results indicated that human dental papilla cells have the ability to form dentin in culture. The formation of mineralized nodules by human dental papilla in vitro provides a useful model for studying the morphogenesis and differentiation of dental papilla ectomesenchyme.

cDNA cloning and sequencing of MH2 domain of Smad2 from human dental pulp cells.

OBJECTIVE: The purpose of this study was to clone and sequence the cDNA of MH2 domain of Smad2 from human dental pulp cells. METHODS: In this study, total RNA was isolated from primary cultured human dental pulp cells and reverse-transcribed into cDNA. The desired DNA product was obtained by nested PCR with 4 smad2 MH2 domain-specific primers. The segment was inserted into pBluescript II SK vector and the resulting plasmid was transformed into E. coli JM109. The double-strand cDNA of positive clone was sequenced by PE317-A automatic sequencing. RESULTS: cDNA of MH2 domain of Smad2 was obtained from human dental pulp cells. The sequence was consistent with that cloned from a human kidney cDNA library. No mutation was found. CONCLUSION: This study provides the first evidence of expression of smad2 in human dental pulp cells, and indicates that TGF-beta signaling may be mediated by Smad2 in human dental pulp cells. The cDNA cloned in pBluescript/S2MH2 could be used for further functional studies of Smad2 and MH2 domain in dental pulp cells.

Effect of IL-1ra on human dental pulp cells and pulpal inflammation.

AIM: This study was conducted to investigate the effect of interleukin-1 receptor antagonist (IL-1ra) on the LPS-induced interleukin-1beta (IL-1beta) synthesis in human dental pulp cells and to assess the role of IL-1ra in pulpal inflammation. METHODS: IL-1beta from human dental pulp cells (HDP) was measured by sandwich ELISA; IL-1ra expression in pulpal tissue was detected by immunohistochemical staining. RESULTS: Stimulation of HDP with increasing concentrations of FnLPS resulted in dose-dependent IL-1beta production. The addition of IL-1ra reduced FnLPS-induced IL-1beta synthesis in human dental pulp cells. Significant inhibition of the FnLPS-induced IL-1beta synthesis was observed when IL-1ra was added before treating with FnLPS for 60 min. Large numbers of IL-1ra positive neutrophils, plasmacytes, endothelial cells and lymphocytes were observed in inflamed pulp tissue. CONCLUSIONS: IL-1ra could reduce LPS-stimulated IL-1beta synthesis, suggesting that IL-1ra may play a role in pulpitis.

[Colorimetric studies on hiding effect of Cosmotech porcelain for laminate restoration].

The hiding effect on color tone of discolored teeth restored with ceramic laminate veneer crown was examined. Translucent (T1, T2), Enamel (E1, E2, E3), Dentin (DA2, DA3, DB2, DB3), Masking dentin (MDA2, MDA3, MDB2, MDB3) in 13 colors and Modifire (M61, M62, M65, M66, M67, M68, M69, M70, M79) in 7 colors of the ceramic materials (Cosmotech porcelain G C Co., Ltd) were examined in this experiments. The colorimetric examination of the color tone backing with the white or black color was carried out by testing for color difference (delta E*ab), value difference (delta L*), chrom and hue of the samples. The result obtained were as follows; 1. Color difference was higher in order of T2 greater than T1 in Translucent greater than E1 greater than E3 greater than E2 in Enamel greater than DB3 greater than DA2 greater than DA3 greater than DB2 in Dentin greater than MDB3 greater than MDA2 greater than MDB2 greater than MDA3 in Masking dentin, and M69 greater than M79 greater than M70 greater than M68 greater than M66 greater than M61 greater than M62 greater than M67 greater than M65 in Modifire. 2. Value difference was higher in order of T2 greater than T1 in Translucent greater than E1 greater than E3 greater than E2 in Enamel greater than DB3 greater than DA2 greater than DB2 greater than DA3 in Dentin greater than MDA2 greater than MDB3 greater than MDB2 greater than MDA3 in Masking dentin, and M69 greater than M70 greater than M79 greater than M68 greater than M66 greater than M61 greater than M67 greater than M65 greater than M62 in Modifire.(ABSTRACT TRUNCATED AT 250 WORDS)

Study of estimation of color recognition on the dentist. On the ability of subjects to discriminate color in terms of hue, value and chroma.

The tooth crown color space model was manufactured and the improvement of the color representation and communication on the dental clinic have been trying. The study of color discrimination by dentist and student viewing with the use of tooth crown color chips reported here in basic knowledge on the color sensitivity of human eye. The test card were 55 x 90 mm in size and the color chip, 5 x 10 mm. The paired color chips were placed on the test card to have a 2 mm distance between them. Color difference of two tooth crown color chips on the test cards was 3.5 (delta E*ab), the combination of hue, value and chroma was constant of all cards. The subjects were 22 people, 6 dentists and 16 dental school students with normal color sensibility. In proportion of method of comparison for surface color (JIS Z 8723), the subject observed the test card which were different of hue, value and chroma on the their naked-eye, were investigated to evaluate their judgement of the test cards. The following results were obtained. The standard of judgment for the color discrimination was made firstly in terms of hue, secondly in terms of value, and thirdly in terms of chroma.