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Periodontitis is an infectious disease caused by an imbalance between the local microbiota and host immune response. Epidemiologically, periodontitis is closely related to the occurrence, development, and poor prognosis of T2D and is recognized as a potential risk factor for T2D. In recent years, increasing attention has been given to the role of the virulence factors produced by disorders of the subgingival microbiota in the pathological mechanism of T2D, including islet β-cell dysfunction and insulin resistance (IR). However, the related mechanisms have not been well summarized. This review highlights periodontitis-derived virulence factors, reviews how these stimuli directly or indirectly regulate islet β-cell dysfunction. The mechanisms by which IR is induced in insulin-targeting tissues (the liver, visceral adipose tissue, and skeletal muscle) are explained, clarifying the influence of periodontitis on the occurrence and development of T2D. In addition, the positive effects of periodontal therapy on T2D are overviewed. Finally, the limitations and prospects of the current research are discussed. In summary, periodontitis is worthy of attention as a promoting factor of T2D. Understanding on the effect of disseminated periodontitis-derived virulence factors on the T2D-related tissues and cells may provide new treatment options for reducing the risk of T2D associated with periodontitis.
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Humans , Diabetes Mellitus, Type 2/complications , PeriodontitisABSTRACT
Objective:To compare the maxillary sinus mucosa's stress distribution when elevated by three lift materials.Methods:Three Finite element models of maxillary sinus mucosa with 0.3 mm thickness elevated by implant,grafting autogenous cancellous bone and hydroxyapatite respectively were established in the specific units.ANSYS finite element analysis software was used to evaluate maxillary sinus mucosa deformation by the simulated closed sinus lift surgery.Differences of Von Mises stress values of mucosa surface were calculated when maxillary sinus mucosa lift height was increased from 1 mm to 5 mm according to the a large deformation theory. Results:The Von Mises stress values on membrane surface elevated by implant,grafting autogenous cancellous bone and hydroxyapa-tite bone substitute materials showed no difference within 5 mm elevation.Conclusion:Closed maxillary sinus floor lifting operation with implant elevating the maxillary sinus membrane directly is a simple and minimally invasive way for sinus floor elevation.
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Objective To research the efficiency of interactive teaching combined with group discussion in prosthodontics course. Methods Totally 40 stomatology students of 2009 grade were divid-ed into 2 groups by stratified random sampling , 6 males and 14 females in each group. Students in con-trol group were taught by traditional teaching method while those in the test group were taught by interac-tive teaching method during prosthodontics course. Knowledge lectures and cases discussion in interactive teaching method were distributed as ratio of 3∶1 in class time , and network interactive teaching was car-ried out after class. Exam was taken after the course, which included single choices(80 questions, 80 points), true or false questions(20 questions, 20 points) and case analysis(5 questions, 50 points). Full marks of the exam was 150 points and exam time was 150min. Then questionnaire survey was carried out, which included the students' interest in learning and cognition of learning difficulty. Exam scores were statistically analyzed by two sample t-test(α=0.05) and the questionnaire survey results were statistically analyzed by Mann-Whitney U test(α=0.05). Results Average scores were(109.22±8.22) in control group and(126.28±8.72) in test group, with statistical differences(F=1.1254, P=0.000). There were statistical differences between control group and test group in studying interest(Z=-2.869, P=0.004) and difficulty(Z=-2.711, P=0.007). Conclusions Initiative, thinking capacity and scores can be enhance by interactive teaching method which is more efficiently than traditional teaching method.
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BACKGROUND:How to avoid iatrogenic maxil ary sinus mucosal perforation after closed maxil ary sinus augmentation. OBJECTIVE:To compare the influence of maxil ary sinus mucosa at different thicknesses on the mucosal perforation in closed maxil ary sinus augmentation operation by using finite element analysis. METHODS:Three finite element models of maxil ary sinus mucosa at different thicknesses of 0.3 mm, 0.5 mm, 0.8 mm respectively and implant with 4.2 mm diameter were established in the SHELL63 units. ANSYS finite element analysis software was used to evaluate maxil ary sinus mucosal deformation by the simulated closed maxil ary sinus augmentation surgery. Differences of Von Mises maximum stress values of mucosa surface were calculated according to the non-linear large-deformation theory. RESULTS AND CONCLUSION:When maxil ary sinus mucosa height was increased from 1 mm to 5 mm, the large deformation was observed in the center of mucosa center. The maximum stress curve slope was shifted mild between 1-4 mm deformation, while shifted abruptly after 4 mm. There was no difference in the value of Von Mises maximum stress values between three maxil ary sinus mucosa at 0.3 mm, 0.5 mm, 0.8 mm thickness, when the lift height was increased from 1 mm to 5 mm (P>0.05). Maxil ary sinus mucosa are faced with a higher risk of mucosal perforation and elastic elongation when maxil ary sinus height is increased more than 4 mm. Maxil ary sinus mucosa at 0.3-0.8 mm thickness are faced the similar risk of mucosal perforation in closed maxil ary sinus augmentation operation within 5 mm. While more considerations should be paid on patients with less than 0.3 mm maxil ary sinus mucosa thickness.
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<p><b>OBJECTIVE</b>To investigate the influence of background color on veneered In-Ceram and Cercon dental ceramics including Vita In-Ceram Electroformed Alumina (AL2), Electroformed Zirconia (Z21), Cercon base color Zirconia and Cercon base Zirconia.</p><p><b>METHODS</b>The colorimetric values of all the materials on noble metal, Ni-Cr alloy, silver amalgam and resin background were measured with a spectrocolorimeter, and the color difference among the groups was calculated.</p><p><b>RESULTS</b>After veneered, the color difference of Z21 Electroformed Zirconia was more distinct against the background of silver amalgam than against the backgrounds of noble metal and resin, but the color differences of the 4 veneered dental ceramics against different backgrounds were unidentifiable by human eyes (δE<1.5).</p><p><b>CONCLUSION</b>After veneered, AL2 electroformed alumina, Z21 electroformed zirconia, Cercon base Zirconia and Cercon base color Zirconia are less influenced by the background color, and covering the background color is therefore not necessary.</p>
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Color , Dental Materials , Dental Prosthesis DesignABSTRACT
A questionnaire survey was conducted among undergraduate international students to investigate the effects of stomatology teaching.The effects of stomatology teaching had been proved to be fair, while some shortcomings had also emerged. In further teaching adjustments have to be made to teaching plans and teachers' Enghsh abilities are expected to be improved.
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Objective: To evaluate the corrosion resistance of Ni-Cr alloy with different coatings in neutral and acid saliva by electrochemistry method. Methods: Measured the self-corrosion potential (Ecorr) and polarization resistance(Rp) curves of Ni-Cr alloy models with different coatings in neutral and acid artificial salivas. Results: The Ecorr of the Ni-Cr alloys all showed positive values, the electrochemistry corrosion and galvanic corrosion were not detected. Conclusion: Ni-Cr alloy with titanium nitride coating, gold electroplating coating, gold-paste layer and gold-porcelain blended layer have both anti-corrosion and esthetical function without changing its own property.
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Objective: To find out the infinity optical thickness of SY-1 silicone elastomers when color difference(△E) is equal to 1.5 . Methods: Silicone elastomer samples with thickness from 0.5 mm to 10 mm of SY-1 silicone elastomer were measured by CIE-1976-L *a *b * relative to CIE source against a white and a black background by using Minolta colorimeter . Color difference was calculated as △E=[(△L *) 2+( △a *) 2+(△b *) 2] 1/2 . The infinity optical thickness of SY-1 silicone elastomer when △E=1.5 was calculated by regression formulation. Result: When △E was equal to 1.5, the infinity optical thickness of SY-1 silicone elastomer was 7.60 mm. Conclusion: In order to get ideal effect the supports should be treated with colorant when the thickness of silicone elastomer covering the surface of supports in maxillofacial prostheses is thinner than 7.60 mm.
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0.05);the elongation (%) 470?9.5,560?8.2 and 470?5.8 (SY-1 versus SY-2 or MDX-4-4210,P
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0.05) respectively. Conclusion: The SY 1 silicon elastomer have suitable physical, mechanical and anti ozone aging properties.
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0.05).Tight integration was found between the two materials in the two groups and there was no distinct interface examined by SEM.Conclusions:GP-084 cellular silicone elastomer and SY-1 silicone elastomer may be adhered completly.
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砄bjective:To compare the adherent ability of Candida albicans on the surface of two kinds of silicone elastomer used as prosthodontic materials and to study the factors affecting the adherence.Methods: Candida albicans were cultured on the surface of SY 1 and MDXA 4210 with or without saliva acquired pellicle for 10 min, then the number of the bacteria was counted.Results:With or without saliva acquired pellicle,the number (1?10 3/mm 2) of C.albicans on SY 1 was 24.5?0.88 and 2.0?0.47 respectively( P 0.05 ).Conclusion:There is little difference between the adherent ability of C.albicans on the two kind of silicone elastomer.Saliva acquired pellicle can decrease the adherence.
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0.05).The elongation at break of SY-1 was stronger than that of MDX4-4210 (P
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Objective: To study the property of galvanic corrosion of soft magnetic alloy and 4 kinds of dental alloys in simulated oral environment. Methods: 6 samples of Ni Cr, TA 2, Ti75 and 30 of Fe 16Cr 2Mo in the size of d 15 mm?3 mm were prepared and put into artificial saliva. An electrochemical method was used in the measurement of electric potential of corrosion (Ecorr), potential dynamic polarization and galvanic current density of different galvanic couple, the anticorrosive property of four galvanic couples was analyzed statistically. Results: The ecorr value(mV) of Ti75, TA 2, Co Cr,Fe 16Cr 2Mo and Ni Cr was -138.31?2.89, -150.35?1.04, -186.21?3.79, -218.35?0.84 and -240.49?1.73 respectively ( P
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Objective:To study the effects of ozone aging on the color stability of the SY-1 silicone elastomer. Methods :40 SY-1 silicone elastomer samples were prepared and grouped into 4 with 10 in each group. The samples in each group were painted with gouache color, oil pigment and inorganic salt respectively, one group was used as the control. Then the samples were treated with ?=10 -4 % ozone at 10～16 mm/s for 72 h. The color of the samples were measured by 1976 CIE L *a *b * standards of chromatic aberration before and after ozone treatment. The chromatic aberration was expressed as △E=〔△L *)2+(△a *)2+(△b *)2〕 1/2. Results :After 72 hours of ozone aging, △E of the samples in the groups of control, gouache color, oil pigment and inorganic salt was 0.55?0.11, 3.55 ? 0.09, 1.40 ? 0.11 and 1.57 ? 0.07 respectively ;Conclusion:Under the ozone aging condition, the SY-1 silicone elastomers stained with oil pigment and inorganic salt may have better color stability than that with gouache color.
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Objective: To evaluate the physical properties of SY-1 silicone elastomer with various ratios of cross-linker to base. Methods: The ratios of cross-linker to base were set at 0.5 %、1 %、 1. 5 %、 2 % 、2. 5 % respectively while other conditions were kept same, then the major physical properties of the elatomer were studied with a tensile tester and ASTMD 2240 method. Results: The elongation(%) due to tension, tensile strength (MPa), laceration strength (kN/m) and hardness (A) of SY-1 silicone elastomer with the ration of 0. 5% of cross-linker to base were 540?47,4. 3?0. 28, 14. 4?2.4 and 18. 0?3. w; those of that with 1% 440 ?54,4.0?0.32,18. 2?3.1 and 24. 0?3. 61 with 1.5% 430?51, 4.1?0. 29, 13.6?2.2 and 25.0?2.1; with 2% 350?46, 2.5?0. 33, 9.0?2.1 and 28.0?1.9; with 2.5% 280?36, 2.0?0. 3, 11.0?2.5 and 29.0? 2.8, respectively. Conclusion: The physical properties of SY-1 silicone elastomer with a ratio of 1% of crosslinker to base are more suitable for prothesis fabrication.
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Objective To study the biosafety of colored alumina-glass composite by mucosa irritation test. Methods The colored alumina-glass composite and a non-irritating material were separately fixed to the oral mucosa of a mouse. The contact parts were examined with bare eye, histologically and cytologically. Results No obvious inflammation of the mucosa was detected in the site where colored alumina-glass composite was in contact. Conclusion Alumina-glass composite has good biosafety.