Objective:To observe the disinfection efficiency of N-doped nano-TiO2 on the curing light-guide rods.Methods:50 light-guide rods from 6 dental clinics were included,the bacteria adhesion on the light-guide rods before and after disinfection with N-doped nano-TiO2 was investigated using ATP bioluminescence method.Results:The RLU value of light-guide rods exposed to the air was 51 -649 before the use of N-doped nano-TiO2 disinfection,after spraying N-doped nano-TiO2 ,the RLU value of light-guide rods was 0 -6(P <0.01 ).Conclusion:N-doped nano-TiO2 has significant sterilization effect on the curing light-guide rods.

China-made 5-axis simultaneous contouring CNC machine tool and domestically developed industrial computer-aided manufacture (CAM) technology were used for full crown fabrication and measurement of crown accuracy, with an attempt to establish an open CAM system for dental processing and to promote the introduction of domestic dental computer-aided design (CAD)/CAM system. Commercially available scanning equipment was used to make a basic digital tooth model after preparation of crown, and CAD software that comes with the scanning device was employed to design the crown by using domestic industrial CAM software to process the crown data in order to generate a solid model for machining purpose, and then China-made 5-axis simultaneous contouring CNC machine tool was used to complete machining of the whole crown and the internal accuracy of the crown internal was measured by using 3D-MicroCT. The results showed that China-made 5-axis simultaneous contouring CNC machine tool in combination with domestic industrial CAM technology can be used for crown making and the crown was well positioned in die. The internal accuracy was successfully measured by using 3D-MicroCT. It is concluded that an open CAM system for dentistry on the basis of China-made 5-axis simultaneous contouring CNC machine tool and domestic industrial CAM software has been established, and development of the system will promote the introduction of domestically-produced dental CAD/CAM system.

China-made 5-axis simultaneous contouring CNC machine tool and domestically developed industrial computer-aided manufacture (CAM) technology were used for full crown fabrication and measurement of crown accuracy,with an attempt to establish an open CAM system for dental processing and to promote the introduction of domestic dental computer-aided design (CAD)/CAM system.Commercially available scanning equipment was used to make a basic digital tooth model after preparation of crown,and CAD software that comes with the scanning device was employed to design the crown by using domestic industrial CAM software to process the crown data in order to generate a solid model for machining purpose,and then China-made 5-axis simultaneous contouring CNC machine tool was used to complete machining of the whole crown and the internal accuracy of the crown internal was measured by using 3D-MicroCT.The results showed that China-made 5-axis simultaneous contouring CNC machine tool in combination with domestic industrial CAM technology can be used for crown making and the crown was well positioned in die.The intemal accuracy was successfully measured by using 3D-MicroCT.It is concluded that an open CAM system for dentistry on the basis of China-made 5-axis simultaneous contouring CNC machine tool and domestic industrial CAM software has been established,and development of the system will promote the introduction of domestically-produced dental CAD/CAM system.

BACKGROUND: Human periodontal ligament fibroblasts (HPLF) is the crucial cells in maintaining the configuration and function of periodontium. Adverse stress may cause HPLF to synthesize more inflammatory agents, which may cause the damage of periodontium.OBJECTIVE: To investigate the role of p38 MAPK of HPLF in the expres sion of inflammatory cytokine of interleukin-6 (IL-6) subjected to mechanical pressure, and explore the mechanism of the occlusal trauma to periodontium.DESIGN: A randomized and controlled trial.SETTING: Pathological Laboratory of the Fourth Military Medical Univer sity of Chinese PLA.MATERIALS: The HPLF were obtained from the middle part of 1/3 pe riodontium of 12 to 16-year-old youth whose 20 healthy permanent premo lar teeth should be extracted for orthodontic need. Main reagents and ap paratus: IL-6 enzyme-linked immunoabsorbent assay (ELISA) kit (Staff Room of Immunology of the Fourth Military Medical University of Chinese PLA); ELISA apparatus (Huadong Electronic Tube Factory); p38 MAPK specific inhibitor of SB203580 (produced by Biochemical Company, ob tained as a present from Professor Jiang, Staff Room of Pathophysiology, Southern Medical University).METHODS: The cells were primarily cultured till the 4-5 passages, and randomly divided into four groups: ①pressure-loading control group: the cell s were not subjected to pressure-loading and without pretreatment; ② pressure-loading group: the cells were subjected to continuous pressure-load ing (200 kPa) but without pretreatment; ③ pretreatment control group: the supernatant were added with 10 g/L dimathyl sulfoxide (DMSO, SB203580 solvent) at 1 hour before pressure-loading, the method and time of pressure loading were the same as those in the pressure-loading group; ④ pretreated group: the cells were pretreated with 1 μmol/L SB203580 (a specific in hibitor of the p38 MAPK) at 1 hour before pressure-loading, the method and time of pressure-loading were the same as those in the pressure-loading group. The cytosol and the supernatant in each group were sampled at 16 and 24 hours after pressure-loading respectively. The IL-6 expressions at different time points were detected with ELISA.MAIN OUTCOME MEASURES: The amount of IL-6 expression in HPLF induced by pressure with or without pretreatment by SB203580, a specific inhibiter of p38 MAPK.RESULTS: The expressions of IL-6 after continuous pressure-loading for 16 and 24 hours in the pressure-loading group were (143.1±0.42) and (49.46±1.01) ng/L, which were obviously higher than those in the pres sure-loading control group [(18.36±0.43), (18.78±0.50) ng/L, P ＜ 0.05]. The expressions of IL-6 after continuous pressure-loading for 16 and 24 hours in the pretreatment group were (56.39±0.72) and (21.52±1.39) ng/L, which were obviously higher than those in the pressure-loading control group [(137.96±0.54), (48.47±0.79) ng/L, P ＜ 0.05].CONCLUSION: p38 MAPK of HPLF acts as important cooperative mechanism to regulate IL-6 synthesis induced by mechanical pressure.

OBJECTIVETo investigate the effect of human serum albumin (HSA) on cell attachment of human gingival epithelial cells (HGE).

METHODSHGE were primary cultured with keratinocyte serum-free medium (KSFM) and dispase. The cultured cells were immunohistochemically stained by monoclonal anti-pan cytokeratin. MTT test was employed to investigate the influence of HSA on the cell attachment on polystyrene surface. The cell growth curve of HGE which were cultured in KSFM with 50 g/L HSA was observed.

RESULTSThe results showed significant decrease in cell numbers within 8 hours after HGE were inoculated, in which the polystyrene surface was preincubated with 50 g/L HSA. But it did not prove to be the case from 10 hours to 24 hours after HGE were inoculated. There were no significant difference within 24 hours in cell numbers between cultured in KSFM with 50 g/L HSA and control. The cell numbers in cell growth curve of HGE in KSFM with and without 50 g/L HSA did not show significant difference.

CONCLUSIONSHSA preincubation on polystyrene were produce inhibitory effect of HGE attachment in early stage.

Cell Adhesion ; drug effects ; Cell Count ; Cell Division ; drug effects ; Cells, Cultured ; Epithelial Cells ; cytology ; drug effects ; Gingiva ; cytology ; drug effects ; Humans ; Polystyrenes ; Serum Albumin ; pharmacology

objective: To investigate the effect of human serum albumin(HSA)on the attachment of human gingival epithelial cells(HGEs)to commercial pure titanium(cpTi).Methods: HGEs were cultured, the cells of passage 2～5 were seeded on to cpTi samples which were preincubated in keratinocyte serum free medium with 50 mg/ml HSA or without HSA. Cell attachment was studied by immunofluorescence analysis.Results: HGEs were cultured and identified by positive expression of cytokeratin. 4,12 and 24 h after seeding attached cells on HSA preincubated cpTi were 218,730 and 849, those on the control 417,745 and 864, respectively.Conclusion: The early stage of cell attachment of HGEs on to cpTi may be inhibited by HSA.

Objective:To observe the changes of c-jun expression in the monkey's temporalis muscles induced by stress reaction under +Gx loads.Methods:Nine male Rhesus macaques were randomly divided into four groups according to Gx loads and its lasting time:control group was exposed to +1 Gx/300 s overloads(n=2),and experimental groups 1(n=2),2(n=2)and 3(n=3)were exposed to +15 Gx/200 s,+21 Gx/165 s or +21 Gx/140 s respectively.Temporalis muscles tissue was fixed with 40 g/L buffered formaldehyde and embedded in paraffin.Histopathological changes were observed under light microscope.The expression of c-jun was detected by immunohistochemical PicTureTM method in the temporalis muscles.Results:Gross and histological analyses showed that no significant pathological changes in the temporalis muscles in different experimental groups.Immunohistochemical staining demonstrated that c-jun was over-expressed in the nuclei of the muscles in the experimental groups,while negative or slight positive staining was observed in the nuclei of muscles in control animals.There was no obvious difference of c-jun expression in different experimental groups.Conclusion:Overload gravity can induce enhanced expression of c-jun in temporalis muscles of the monkeys received +Gx loads.

Objective To investigate the correlation of the prevalence of periodontitis with age and course of disease in patients with type 2 diabetes.Methods A total of 884 patients with diabetes (both sexes,aged 35-79 yr) were involved in present study.Diagnosis of periodontitis was made according to the 1999 WHO standard,and of type 2 diabetes to the 1997 WHO standard.Age,gender,course of diabetes and periodontal state of those patients were recorded.The patients were grouped according to their age (10 yr interval) and course of disease (5 years interval).Based on the grouping,the collected data were input into ACCESS data bank and statistically analyzed with SAS software,and the prevalence of periodontitis were then compared.Results The prevalence of periodontitis in patients with type 2 diabetes increased with the increasing of age and with the prolonging of disease course (P

Objective: To observe the expression of proteins Rb and P 53 in leukoplakia (LK) and squamous cell carcinoma (SCC) of oral muco sa. Methods: The expression of proteins Rb and P 53 was determined by immunohistochemical S-P method. Paraffin sections of 33 s amples of SCC and 20 of LK were immunohistochemically stained and analyzed. Results: (1)The expression of Rb in OLK, OSCC was not si gnificantly different from that in normal oral mucosa ;(2)the overexpression of mutant P 53 were found in OLK and its expression was increasing with dysp hasia degree (P

Objective: To obtaine the parameters of tooth mobil ity in people with normal health teeth . Methods:Tooth mob ility of 1 4, 1 4 in 12 subjects (7 males and 5 females, aged 21 to 23 years old) was measured by FX-1 tooth mobility measurement system 6 times a day for 5 days.The data were statisticaly analyzed. Results: The average tooth mobility parameters Q and R varied significantl y (P0.05).Conclusion: The tooth mo bility parameters of S,K,t1 and t2 can steadily reflect the changing of tooth mobility.