Animals ; Dental Implantation, Endosseous ; adverse effects ; Dental Implants ; adverse effects ; Dental Prosthesis, Implant-Supported ; adverse effects ; Dentition ; Humans ; Malocclusion ; etiology ; Maxillofacial Development

Objective To explore the effect and mechanism of relaxin on the production of extracellular matrix (ECM) excreted by high glucose stimulated human renal mesangial cells.Methods Cultured human mesangial cells (HMCs) were divided into three groups:(1) normal glucose group (NG,5.5 mmol/L D-glucose),(2) high glucose group (HG,30 mmol/L D-glucose),and (3) high glucose + relaxin group.Cell count kit (CCK8) was used to examine the cell proliferation.The levels of fibronectin and collagen type Ⅳ in the culture supernatants were examined with a solid-phase enzyme-linked immunoadsorbent assay (ELISA);Western blot method was used to detect the expression of α-smooth muscle actin (α-SMA) protein.The transforming growth factor-β1 (TGF-β1) mRNA expression was detected with quantitative polymerase chain reaction (qPCR) method.Results No proliferation and inhibition effects were observed in both normal and high glucose group.Compared to the normal glucose group,the levels of fibronectin,and collagen type Ⅳ increased significantly (57.28 ± 0.59 vs 41.85 ± 0.03,56.52 ± 0.88 vs 33.80 ± 0.24,P ＜ 0.01)after cultured 48 h in high concentration of glucose.Compared to the high glucose group,a significantly decreases of fibronectin and collagen type Ⅳ (47.08 ± 0.03 vs 57.28 ± 0.59,36.16 ± 0.52 vs 56.52 ±0.88,P ＜0.01) were observed in the relaxin treated group.The expressions of α-smooth muscle actin and TGF-β1 were decreased (P ＜0.01).Conclusions Relaxin can suppress the overproduction of ECM excreted by HMC cultured in high ambient glucose,and its mechanism is partly due to the inhibition of TGF-β1.

OBJECTIVETo study the mechanical properties of two kinds of composite resins reinforced by preimpregnated glass fibers.

METHODSSinfony and belleGlass composite resins were used to make standard samples (25 mm x 2 mm x 2 mm) with and without glass fibers. After all specimens were stored for 24 hours in distilled water at (37 +/- 1) degrees C, the flexural strength and flexural modulus were measured on a universal test machine.

RESULTSBoth flexural strength and flexural modulus of Sinfony composite reinforced by the glass fibers became significantly increased, which were (555.76 +/- 67.31) MPa and (12.59 +/- 3.06) GPa respectively, and 4.5 and 2.5 times much more than those of the specimens without glass fibers (P = 0); the flexural modulus of belleGlass composite became significantly increased, which was (14.10 +/- 2.88) GPa, and 0.9 time much more than the specimens without glass fibers (P = 0), but the improvement of flexural strength was not significant.

CONCLUSIONGlass fibers can improve the mechanical properties of composite resins, but the reinforcement effect is different between different resins.

Composite Resins ; chemistry ; Glass ; chemistry ; Materials Testing

OBJECTIVETo evaluate the mandible angle and to investigate the relationship of angle size to gender, age-group, cortical thickness at the mandibular angle (CTMA), height of mandibular residual body, and edentulous period in the elderly edentulous subjects.

METHODSA total of 356 panoramic radiographs of three groups of subjects were evaluated: the young dentate group, 131 subjects (mean age: 27); the older dentate group, 97 (mean age: 64); and the elderly edentulous group, 128 (ages 76, 81, or 86). Mandibular angle size, CTMA, and height of mandibular residual body were measured from panoramic radiographs. A structured questionnaire was used to determine the history of edentulousness.

RESULTSDifference in angle size was found between dentate men and women (P < 0.05, P < 0.001), but not between the elderly edentulous men and elderly women. The elderly edentulous subjects had larger mandibular angles than did older dentate subjects (P < 0.001). The angle size was negatively related to CTMA only among 76-year-old edentulous women (P < 0.01) and negatively associated with average height of the mandibular residual body in the edentulous men and women (P < 0.01). No association existed between angle size and duration of edentulousness.

CONCLUSIONSElderly edentulous subjects have large mandibular angles and the angle size is correlated with low-height of the mandibular residual body, which suggests that masticatory function of natural dentition and complete denture may influence change of the mandibular angle. The significant relationship of mandibular angle size to CTMA probably indicates the effect of systemic factors on change in the mandibular angle.

Adolescent ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Alveolar Process ; diagnostic imaging ; pathology ; Cephalometry ; Female ; Humans ; Jaw, Edentulous ; diagnostic imaging ; Male ; Mandible ; diagnostic imaging ; pathology ; Middle Aged ; Radiography

Objective To investigate the feasibility of ~1H-MR spectroscopy(~1H-MRS)imaging to quantitatively detect fatty liver.Methods Twenty patients with fatty liver and 11 healthy volunteers underwent plain CT scan,conventional MR imaging and ~1H-MRS analysis.The blood lipid and liver function were tested on the same day as the MR examination.~1H-MRS sequence measured the peaks of H_2O and lipid,and the areas under the peaks.The relative contents of the lipid compound were calculated,and compared with the results of CT scan and liver function tests.Results The CT values of the normal group and the fatty liver group were(59?9)HU and(24?11)HU respectively.On ~1H-MRS a protruding high H_2O peak and a flat low lipid peak were observed in the normal group,while the protruding high H_2O peak and a high lipid peak appeared in the fatty liver group.The values of lipid peak in the normal group and the fatty liver group were(0.05?0.01)?10~5,(0.70?0.24)?10~5 respectively(t=4.32,P0.05),the areas under the lipid peak were(1.36?0.73)?10~9、(2.35?1.15)?10~9 respectively(t=5.21,P0.05).Conclusion ~1 H-MRS imaging is feasible to quantitatively detect liver fat and is a non-invasive method for detecting early fatty liver.

OBJECTIVETo compare the difference of stress distribution among models with different fiber frameworks.

METHODSFour models were generated in Marc 2003 software. Four types of loads simulating normal mastication were selected. The stress within models was calculated, and output by means of graph and data.

RESULTSThere was stress concentration around connectors and retainers near connectors under cusp -fossa load, occlusal even load, and lateral load. When dentures were reinforced with fiber framework, area of stress concentration and principal stress max could decrease in comparison with pure composite resin bonded fixed partial denture. Under buccal-lingual load, there was another stress concentration around central fossa beside above two stress concentration areas. Only modified fiber framework constructed with both mesial-distal and lingual-buccal directional glass fiber could markedly reduce principal stress under buccal-lingual cusp loads.

CONCLUSIONUnder 4 types of loads simulating normal mastication, three critical regions were disclosed at the area of retainers adjacent connectors, connectors and occlusal central fossa and fissures. Only modified fiber framework constructed with both mesial-distal and lingual-buccal directional glass fiber could markedly reduce stress concentration under buccal-lingual cusp loads.

Composite Resins ; Denture Design ; Denture, Partial, Fixed, Resin-Bonded ; Glass

OBJECTIVETo analyze influence of fiber framework design on fracture strength of posterior glass fiber-reinforced-composite resin-bonded fixed partial dentures (GFRC-RBFPD).

METHODSBased on established three-dimensional finite element models of GFRC-RBFPD for restoring the second mandibular premolar or the first mandibular molar, traditional fiber framework design and modified fiber framework design were analyzed. Two types of load, including cusp-fossa load and buccal-lingual cusp load, were selected. Load values were 400 N on premolar and 600 N on molar respectively. The fracture strength of GFRC-RBFPD was calculated.

RESULTSUnder cusp-fossa load, the fracture strength was 1340 N for both types of fiber frameworks of premolar GFRC-RBFPD, and 864 N for traditional framework and 875 N for modified framework of molar GFRC-RBFPD. Under buccal-lingual load, the fracture strength of premolar GFRC-RBFPD was 792 N for traditional framework and 1019 N for modified framework; that of molar GFRC-RBFPD was 645 N for traditional framework and 652 N for modified framework.

CONCLUSIONSThe modified fiber framework obviously improved the strength of premolar GFRC-RBFPD and only slightly improved that of molar GFRC-RBFPD.

Dental Prosthesis Design ; methods ; Dental Stress Analysis ; Denture, Partial, Fixed, Resin-Bonded ; Finite Element Analysis ; Glass ; Humans ; Molar

Objective To design and develop new types of health education materials which are suitable for fishermen and boatmen in endemic areas of marshland and lake regions,and to observe their application effects. Methods A total of 292 adult fishmen and boatmen who lived in Houshan Village,Yugan County,the schistosomiasis endemic area of Poyang Lake Re?gion,were selected randomly and investigated by questionnaires to understand the status of their knowledge,attitudes,practic?es on schistosomiasis control as well as the channels for getting information on schistosomiasis control and the materials that they were willing to accept. Then the information and materials suitable for the target population were developed together by the re?searchers and the volunteers of the villagers through focus group discussions,personal interviews and the Delphi method. Re?sults A series of participatory health education materials of schistosomiasis control targeted to the fishmen and boatmen were developed,including 2 live posters,2 picture puzzles,2 short opusculums and one song about schistosomiasis control. The field application showed that 98.97%,84.38%,78.35% and 80.93% of the participants considered those materials had scientificity, intelligibility,interestingness and practicability,respectively. Conclusion The participatory health education materials of schistosomiasis control is suitable for fishmen and boatmen,which can be used for reference by other endemic areas in marsh?land and lake regions.

OBJECTIVETo study the natural head posture (NHP) of edentulous patients compared with dentate people and to understand NHP shift immediately inserting complete dentures and three months after denture wearing.

METHODSThe NHPs of twenty edentulous patients and twenty-two dentate subjects were recorded with cephalometric technique. The NTPs of edentulous patients were exposed three times, before inserting, right after inserting and three months after inserting dentures. The NHPs of dentate subjects were recorded once as a controlled group. Six angles measured from the radiographs were evaluated for the NHP and three angles and two linear measures for the mandibular position.

RESULTSCompared with dentate subjects, the craniomandibular angles of the edentulous patients increased and the camber of the cervical columns decreased, but changes of the NHP were not significant. The mandible showed a significant upward moving (P < 0.05) and an insignificant forward moving. At the time of denture insertion, the camber of the cervical columns significantly increased (P < 0.05). Three months after using the dentures, the craniomandibular angles of the patients obviously decreased. (P < 0.05).

CONCLUSIONThe shift of NHP after denture inserting does exist. The shifted NHP of the patients with dentures is a new balanced posture and closer to the normal position than the NHP of them without dentures.

Adult ; Aged ; Aged, 80 and over ; Cephalometry ; methods ; Denture, Complete ; Female ; Head ; physiopathology ; Humans ; Male ; Mandible ; physiopathology ; Middle Aged ; Mouth Rehabilitation ; methods ; Mouth, Edentulous ; physiopathology ; rehabilitation ; Neck ; physiopathology ; Posture

Objective To measure passive tactile threshold of implant-supported single crowns (ISSC) in six orthogonal orientations,to analyze impact factors,and to guide the occlusal adjustment in a personalized manner.Methods The passive tactile thresholds of 24 implant-supported single crowns (5 maxillary anterior teeth,7 maxillary posterior teeth and 12 mandibular posterior teeth) from 19 ISSC patients (8 men and 11 women,from 25 years old to 56 years old) were measured in six orthogonal orientations (four horizontal orientations of labial or buccal,lingual,mesial and distal,and two axial orientations of apical and coronal) using a digital test system for tactile function of teeth.SPSS 19.0 for windows was used to analyze impact factors,using double-sided test,with a significance level of 0.05.Paired-samples t test was used to test the difference between implant-supported single crowns and the controlled natural teeth,and between different time points.One-way ANOVA was used to test the difference between different orientations,maxilla-mandibular anterior-posterior,and men-women.Results The passive tactile thresholds of ISSC and control teeth were (1282 ± 709) and (40 ± 40) mN respectively.The difference was of statistical significance (P ＜ 0.001).The passive tactile thresholds of buccal-lingual,mesial-distal and axial of ISSC were (1334 ± 696),(1102 ± 605) and (1412 ± 791) mN respectively,of which,the difference between mesial-distal and axial was of statistical significance (P ＜ 0.05).The passive tactile thresholds of ISSC of maxillary anterior teeth,posterior teeth and mandibular posterior teeth were (1003 ± 616),(1302 ± 620) and (1386 ± 769) mN respectively,of which,the difference between maxillary anterior teeth and posterior teeth was of statistical significance (P ＜ 0.05).The passive tactile thresholds of ISSC of men and women were (1751 ±784) and (946 ± 393) mN respectively,the difference was of statistical significance (P ＜ 0.001).The passive tactile thresholds of ISSC of one-week and one-month after wearing the teeth were (1421 ± 826) and (1411 ± 814) mN respectively,the difference was of no statistical significance (P ＞ 0.05).Conclusions The passive tactile threshold of ISSC was more than 65 times as much as that of the natural teeth.There was statistical significance between different orientations,between maxillary anterior and posterior teeth,and between men and women.No statistical significance was found between maxillary and madibular posterior teeth and between one-week and one-month after wearing the teeth.