1.Evaluation of IPS-Empress Ⅱ ceramic crown:A 5-year clinical study
Journal of Practical Stomatology 2001;0(01):-
Objective: To evaluate the clinical performance of IPS-Empress Ⅱ ceramic crown in a five-year period.Methods:IPS-Empress Ⅱ ceramic crown was applied in 130 teeth treatment of 39 patients. The restorative cases include the single tooth missing, acquired tooth body defect, malformed teeth and discoloration caused by tetracycline, fluoride and the root canal treatment. The 130 teeth were investigated after luting in two weeks, 6, 12 to 60 months respectively. Modified Ryge criteria were used to assess the integrity of restoration, gingival health, color match, marginal adaptation, and sensitivity.Results:More than 96.2% restorations were found to be intact and had excellent marginal adaptation. Little wane existed in one crown at the incisal area. One crown fell with its post caused by failed post adhere. Due to the heavy occlusion force, one of the posterior bridge cracked. Obvious inflammation was found in 3 teeth and only two teeth suffered apicitis. No secondary caries and unsatisfactory color match were found in each follow-up examination. Conclusion:IPS-Empress Ⅱ ceramic crown and bridge is a reliable and ideal choice for the anterior aesthetic restoration.
3.Two dimensional finite element analysis of ceramic veneer bonding layer
Cong FAN ; Hailan FENG ; Li LIU
Journal of Practical Stomatology 1995;0(04):-
Objective: To intimately assess the internal stress distribution in ceramic veneer bonding layer. Methods:Six buccolingual cross section models of the incisor restored with IPS-Empress ceramic veneer were built with the MSC/NASTRAN software. 2D-finite element method was used to analyze the stress distribution regularity of the bonding layer on the models under different functional load. Results: Stress concentration areas of ceramic veneer bonding layer were regularly located on the incisal margin and cervical margin. Under the same condition, incisal load caused highest stresse on the adhesive layer. Following the load shift from incisal to gingival area, the stress was gradually decreased.When the functional load acted on the palate margin of the restoration, the compressive stress on the bonding layer was significantly increased. Different load angle generated stress change in the bonding layer. The shear stress on adhesive layer increased following the horizontal load angle increasing close to the debonding level. Among the different incisal reduction designs there was no significant Von Mises stress variation under the same load condition. However, when the incisal edge was reduced by more than 4 mm, the tensile stresses in the bonding layer greatly increased. Conclusion: Restoration margin should be kept away from the tooth contact area, be exposed to minimal occlusion contact. The functional load should be induced to follow the tooth long axis. Edge to edge occlusion should be avoided. When incisal areas need to be altered, the incisal overlap or butt margin design will not cause any stress problem in the bonding layer. When restoring the incisal defect for more than 4 mm, the bonding agents must be selected carefully.
4.Predictors of catheter-related bladder discomfort after urological surgery.
Cong, LI ; Zheng, LIU ; Fan, YANG
Journal of Huazhong University of Science and Technology (Medical Sciences) 2014;34(4):559-62
The aim of this study was to figure out the predictors of early postoperative catheter-related bladder discomfort (CRBD) after urological surgery. We designed a prospective observational study in our hospital. Consecutive adult patients undergoing surgery under general anaesthesia or epidural anaesthesia necessitating urinary catheterization were included during a 3-month period. severity of bladder discomfort was assessed on a 4-point scale: (1) no pain, (2) mild pain (revealed only by interviewing the patient), (3) moderate (a spontaneous complaint by the patient of a burning sensation in the urethra and/or an urge to urinate and/or sensation of urethral foreign body without any emotional agitation) and (4) severe discomfort (agitation, loud complaints and attempt to remove the bladder catheter associated with a burning sensation in the urethra). Predictors of CRBD were identified by univariate and multivariate analysis. Totally, 116 patients were included, of which 84.5% had CRBD (mild CRBD: 40.5%; moderate or severe CRBD: 44.0%) at day 1, while 31.9% developed CRBD (mild CRBD: 29.3%; moderate or severe CRBD: 2.6%) at day 3. We evaluated 9 potential forecast factors of CRBD, and univariate Chi-square test showed male gender [OR=2.4, 95%CI (1.1-5.6), P<0.05], abdominal open surgery compared with transurethral surgery [OR=0.3, 95%CI (0.1-0.6), P<0.05], abdominal surgery compared with laparoscopic surgery [OR=3.3, 95%CI (1.2-8.9), P<0.05] and history of catheterization [OR=0.5, 95%CI (0.2-0.9), P<0.05] were independent predictors of moderate or severe CRBD in the patients after surgery. While multivariate logistic regression analysis showed that the abdominal open surgery [EXP(B)=3.074, 95%CI (1.3-7.4), P<0.05] and the history of catheterization [EXP(B)=2.458, 95%CI (1.1-5.9), P<0.05] might contribute more to the occurrence of moderate or severe CRBD. In conclusion, this observational study identified that the type of surgery and the history of catheterization might be predictive factors of moderate and severe CRBD after urological surgery.
6.Effect of thermal conductivity on apical sealing ability of 4 dental gutta-percha cones
Cong FAN ; Chongyang YUAN ; Jichuan ZHANG ; Xiaoyan WANG
Journal of Peking University(Health Sciences) 2017;49(1):110-114
Objective:To investigate the effect of thermal conductivity on the apical sealing ability of different dental gutta-percha cones during the warm vertical condensation obturation.Methods:Four kinds of dental gutta-percha cones were used in this study:Bio-GP points (BP,B&L,Korea),large-tapered gutta-percha (DP,DENTSPLY,America),PROTAPER Universal gutta-percha points (DPP,DENTSPLY,America) and mtwo gutta-percha points (VP,VDW,Germany).Volume differences method was used to determine the main components and the thermal conductivity determinator was used to measure the thermal conductivity of these dental gutta-percha cones.Furthermore,20 cones randomly selected from each kind of dental gutta-percha cones.And 10 cones of each dental gutta-percha cones,which were cut out the part of 4 mm in length from the apical end,were heated (200 ℃) from the upper end without compression,and the temperature of the gutta perchacones surface was monitored in time by the infrared thermal imager during the whole heating process.In addition,the rest of the 10 cones of each dental gutta-percha cones were used to obturate the root canal in the transparent root canal resin model using warm vertical condensation technique.The cross-sectional surface was observed by stereomicroscope (× 40) at 1 mm and 3 mm from the working length and the gutta-percha obturation area proportion was measured and analyzed.The data were analyzed by one-way ANOVA.Results:The proportion of inorganic fillers (80.90% ± 1.14 %) (P < 0.05) and the thermal conductivity (2.247 ± 0.002)of DP was siguificantly higher than BP (79.28% ± 3.88%,1.179 ± 0.003),DPP (68.46% 5.09%,0.604 ±0.001),VP (78.86% ± 1.87%,1.150 ±0.001) (P <0.05).During the thermal obturation without compression at the setting temperature (200 ℃),DP could achieve 65 ℃ beyond 1 mm from the heating point,and BP,DPP and VP only reached 65 ℃ within 1 mm.After warm vertical condensation obturation,all the groups showed increased gutta-percha obturation area proportion.At the position of WL-3,DP (96.89% ±0.03%) showed significantly higher proportion of gutta-percha obturation area than BP (95.47% ±0.06%),DPP (95.21% ±0.03%) and VP (95.15% ±0.03%) (P < 0.05).Conclusion:DP contains more inorganic fillers,possesses higher thermal conductivity,and leads a better apical sealing ability than BP,DPP and VP at the position of WL-3 during warm vertical condensation obturation.
7.Corneal nerve fiber damage in different stage of diabetic retinopathy patients with type 2 diabetes
Wei FAN ; Xiangwei XIONG ; Huan ZOU ; Cong ZHANG ; Rongdi YUAN
Chinese Journal of Ocular Fundus Diseases 2017;33(2):157-161
Objective To observe the corneal nerve fibres damage in different stage of diabetic retinopathy (DR) with type 2 diabetes.Methods A cross-sectional study.One hundred and twenty eyes of 120 patients with type 2 diabetes served as diabetes group.According to International Clinical Diabetic Retinopathy Disease Severity Scales (2002),diabetes patients were classified into 4 subgroups:patients without diabetic retinopathy (NDR),patients with mild or moderate non-proliferative diabetic retinopathy (mNPDR),patients with severe non-proliferative diabetic retinopathy (sNPDR) and patients with proliferative diabetic retinopathy (PDR),each subgroup has 30 eyes of 30 patients.Another 30 eyes of 30 healthy participants served as control group.All eyes were scanned with HRT3 in vivo corneal confocal microscopy.Images of sub-basal nerve plexus were quantified including nerve fiber length (NFL),nerve fiber density (NFD),nerve fiber branch density (NFB),and nerve tortuosity (NT).The correlations of corneal nerve fiber with age,duration of diabetes and glycated hemoglobin (HbA1 c) were analyzed using Spearman correlation analysis.Results NFL,NFD and NFB were found to be significantly lower in diabetic patients (F=147.315,142.586,65.898;P=0.000,0.000,0.000),NT was significantly greater in diabetic patients (F=39.431,P=0.000),when compared to control group.In diabetic patients,NFL,NFD and NFB were gradually reduced with DR severity,NT was gradually increased with DR severity.While the difference ofNFL,NFD,NFB,NT was not statistically significant between sNPDR and PDR subgroups (P>.0.05),but was statistically significant between other subgroups (P<0.05).Spearman correlation analysis results showed that age (r=-0.071,-0.080,0.001,0.100;P=0.391,0.328,0.991,0.224) and HbAlc (r=-0.109,-0.115,-0.126,0.025;P=0.238,0.211,0.169,0.781) had no correlation with NFL,NFD,NFB,NT.Duration of diabetes was negatively correlated with the NFL,NFD (r=-0.212,-0.264;P=0.020,0.004),positive correlated with NT (r=0.261,P=0.004),and had no correlation with NFB (r=-0.119,P=0.194).Conclusions Corneal nerve fiber loss and nerve tortuosity increased were found in patients with type 2 diabetes,and even without diabetic retinopathy.The progress of corneal neuropathy was correlated with the severity of DR,but it was not change significantly between sNPDR and PDR.
8.Expression and the Significance of MCP-1 and FN in Middle Ear Cholesteatoma Epithelium
Yan GAO ; Yibing YANG ; Linhai CONG ; Yong TANG ; Fan ZHANG
Journal of Audiology and Speech Pathology 2013;(5):501-504
Objective To study the expression of monocyte chemotactic factor -1(MCP-1) and fibronectin (FN ) in secondary acquired middle ear cholesteatoma epithelium ,and to investigate the ability of cholesteatoma of e-rosion .Methods MaxVisionTM immunohistochemical method was used to detect the expression of MCP -1 and FN in the secondary acquired middle ear cholesteatoma tissues from 30 patients ,in the retroauricular skin from 20 pa-tients and in the retroauricular skin from 16 normal subjects .Then we scanned it into a computer by an image scan-ner and quantified the gray value of them using commercial software .Results MCP-1 appeared to be localized in all epithelial layers of middle ear cholesteatoma ,particularly in the spinous layers .The positive expression rates of MCP-1 was 70% ,the gray value was 147 .2 ± 20 .1 ,which were siginificantly higher than those of in the retroau-ricular skin from patients(35% ,200 .8 ± 18 .4)and from normal subjects(37 .5% ,193 .3 ± 15 .5)(P<0 .05) .The ex-pression of FN in all epithelial layers of middle ear cholesteatoma were abundantly stained ,especially in the basal and spinous layers and the matrix of cholesteatoma .The positive expression rates of FN was 76 .7% ,the gray value was 147 .2 20 .1 ,which were siginificantly higher than those of in the retroauricular skin from patients (30% ,195 .0 ± 12 .9)and from normal subjects(31 .3% ,191 .6 ± 13 .5)(P<0 .05) .It showed statistically significant correlation between the expression of MCP -1 and FN and the erosion ability of middle ear cholesteatoma (rmcp-1 = -0 .682 , rfn = -0 .531 ,P<0 .01) .There was not linear correlation between the expression of MCP -1 and FN .Conclusion MCP-1 and FN are overexpressed in middle ear cholesteatoma .There was correlation between the expression of MCP-1 or FN and the erosion ability of middle ear cholesteatoma ,indicating that MCP -1 and FN may play an im-portant roles in invasive behavior of cholesteatoma .
9.The Present Status on Classification of Phytoplasmas
Fan LAI ; Yong LI ; Qi-Cong XU ; Guo-Zhong TIAN ;
Microbiology 1992;0(02):-
The history and present status of phytoplasma classification are introduced briefly in this paper.The newly classification methods and rules for the description of Candidatus species are reviewed.The key problems and direction on the classification and identification of phytoplasmas in China are discussed.
10.Improving doctor-patient relationship, enhancing the oral cavity medical service effect
Ming-cong YANG ; Xiao-ping FAN ; Xue-rong XIANG
Chinese Journal of Medical Education Research 2011;10(7):851-853
While the medicine pattern of biomedicine turn to biological-psychology-society, the medical trouble communication becomes more and more important in the medical service. Good medical trouble communication ability is the essential condition of doctor. As oral cavity clinicians, only by gasping the principle of communication can we appropriately utilize some skills of communication exchange,establish the good medical trouble relations with the patient and achieve the good treatment result finally.