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Objective: To improve the bioactivity of PEEK by chemical methods. Methods: PEEK samples were treated by polish only (group (1)) ; concentrated sulfuric acid for 5 min (group (2)) ; concentrated sulfuric acid for 10 min (group (3)) ; concentrated sulfuric acid for 5 min, followed by treatment of hydrogen nitrate for 5 min (group (4)) and mineral chameleon and ortho-phosphoric acid (group (5)) respectively (n = 9) . Then, all samples were treated by water at 100 ℃ for 4 h. The sample surface was observed by FE-SEM, the chemical comporent of the samples was analyzed by XPS. BMSCs were cultured on the sample surface for 4 h and observed by SEM. Results: The sample sureface in group (1) was smooth, in group (2), (3) and (4) was with 3 D ethmoidal foramen structure, in group (5) with petal-like from. The sulfur content (Wt％) of the samples of group (1), (2), (3), (4) and (5) was 0, 2. 45 ± 0. 22, 3. 48 ± 0. 16 (vs (1), P= 0. 000), 1. 79 ± 0. 05 (vs (1) P = 0. 002) and 0 respectively. BMSCs cultured on the sample surface of group (2), (3), (4) and (5) were more and with more pseudopod. Conclusion: The bioactivity of PEEK can be enhanced after acid pickling. Water bath and nitric acid treatment can remove the residual acid and further enhance the bioactivity of PEEK.
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Objective:To observe the effects of low intensity pulsed ultrasound(LIPUS) on the osteogenic differentiation of rat bone marrow mesenchymal stem cells(BMSCs) on titanium surface.Methods:BMSCs from Wistar rat bone marrow were respectively cultured on the flat titanium surface and the large grain blast acid etched(SLA) titanium surface,and induced by mineralization medium.Then,the cells were interfered by LIPUS and a control condition.Alkaline phosphatase(ALP) were quantitative determinated after 3 and 7 d mineralization induction respectively,ALP staining were observed after 14 d induction.Alizarin red staining were observed after 21 d mineralization induction.Osteogenic related protein and gene expressions were detected after mineralization induction.Results:ALP in culture medium of LIPUS group was higher than that of the control group after 3 d and 7 d mineralization induction(P＜0.05).LIPUS group showed stronger ALP staining and alizarin staining,and more mineralized nodules than control group.The expression of osteogenic related proteins,including Runx2,BMP2,OPN in LIPUS group increased.Osteogenic related genes expression,including ALP,Runx2,BMP2,OPN,OCN and Col-1 of the LIPUS group increased.Conclusion:The osteogenic differentiation of BMSCs on the fiat titanium surface or SLA titanium surface can be promoted by LIPUS.
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Objective To investigate the changes of myosin heavy chain ( MyHC) isoforms in rat masseter muscle fibers caused by chronic sleep deprivation ( CSD) and a possible link with the pathogenesis of temporomandibular joint disorders ( TMD ) .Methods Total 180 male rats were randomly divided into three groups( n=60 per group): chronic sleep deprivation group ( CSD),cage control group ( CC),and large-platform control group ( TC ) .Each group was further divided into three subgroups ( n=20 in each group)according to the observation time point(7,14,and 21 days).The expression of MyHC isoforms in mas-seter muscle fibers was investigated by real-time quantitative PCR,Western blotting and immunohistochemi-cal staining.Results The expression of MyHC-Ⅰ,MyHC-ⅡA and MyHC-ⅡB deep and shallow masseter muscle in CSD7d group had differention with the control group(MyHC-Ⅰ:(0.314±0.005,0.134±0.005, P0.05) ,and there were no differences between the CC and TC groups at any time point.Conclusion These findings suggest that CSD alters the ex-pression of MyHC isoforms,which may contribute to TMD pathogenesis.
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Objective To investigate the role of psychological intervention in the prevention of the temporomandibular joint disease (TMD) , through the observation of the relative changes in the rat TMJ under psychological stress after psychological intervention. Methods The rat model of communication box was built to exert the psychological stress. The antianxiety agent was applied before stress, and the stressor was removed after stress. The expression of the proinflammatory cytokines IL-1 and TNF-α in the mandibular condylar chondrocytes in rat TMJ was detected by ELISA and RT-PCR. Results The RT-PCR results showed that the expression of IL-1 mR-NA increased into the peak in the 1st week, weakened in the 3rd week, and returned to normal in the 5th week, while the TNF-αmRNA peaked in the 1st week, returned to normal in the 3rd week. The ELISA results showed that there was no significant difference of the OD value of the serum IL-1 and TNF-α(0. 095 ±0. 006,0. 077 ± 0.007,0.069 ±0.009 ;0.079 ±0.010,0.075 ±0. 009,0.079 ± 0.012) in the antianxiety agent group (0. 107 ± 0.024,0. 101 ±0.005,0.088 ±0.010)and the stressor removal group(0. 090 ±0.016,0. 088 ±0.005,0.089 ± 0.011) , compared with the control group(0.087 ±0.004,0.090 ±0.009,0.089 ±0.010;0.074 ±0.008,0.069 ±0.015,0.068 ±0.011) (P>0.05), while significant differences were observed when compared with the psychological stress group(0.282 ±0.045,0.226 ±0.021,0.092 ±0.002;0. 164 ±0.009,0.123 ±0.013,0.091 ± 0.006) (P<0.05 ). Conclusion Application of the antianxiety agent and stressor removal could effectively counter the influence of psychological stress to TMJ, which provides good experience for the clinical prevention of TMD.
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Objective To investigate the repair effect of low intensity ultrasound on radioactive mandibule bone to provide new idea for prevention of osteoradionecrosis of the mandibule after irradiation.Methods The animal models of radioactive mandibular injury were made and treated with low intensity ultrasound.Low intensity ultrasound treatment group ( Group Ⅱ ) and not with low intensity ultrasound treatment group (Group Ⅰ ) were observed by microvessel density detection,micro-CT,ponceau trichrome stain and so on,and compared with control group.Then,the obtained data were statistically analyzed.Results The animal models of radioactive mandibular injury were successfully established.The microvessel density in Group Ⅱ was greater than that in Group Ⅰ.The bone volume fraction,trabecular thickness,bone surface/bone volume and the trabecular number in Group Ⅱ were significantly larger than those in Group Ⅰ (P ＜ 0.05).The ponceau trichrome staining showed that the osteocytes largely disappeared and that the cancellous bone trabecular atrophied in Group Ⅰ,while new bone formation,trabecular and numerous osteoblasts around trabecular were largely observed in Group Ⅱ.Conclusion Low intensity ultrasound has a good recovery effect on bone tissue after irradiation.
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Objective To observe the influence of psychological stress and countermeasure implementation upon the temporomandibular joint ( TMJ ) articular disc and external pterygoid muscle in rats,providing experimental and theoretical evidence for clinical treatment of psychological stress-induced temporomandibular disorders (TMD).Methods The animal models treated by psychological stress induced by alternating current box were established.Before and after subjected to psychological stress,rats were given anxiolytic drugs to eliminate stressors.For all the rats in control group,psychological stress group ( PS group),and psychological stress plus anxiolytic drug injection group ( ( PS + DI) group),the microstructure of TMJ articular disc and external pterygoid muscle the changes in RNA expression of interleukin-1 ( 1L-1 ) were investigated by using transmission electron microscope (TEM),scanning electron microscope ( SEM ) and RT-PCR methods,respectively.Statistical analysis was performed upon the obtained test results.Results The TEM showed pathlogical changes in rats'pterygoid muscles of PS group at 1,3 and 5 weeks,including edema,reduction of substrate density and microchondrial cristae.Instead,these structures were all showed normal in the group of PS + DI and recovering group after removal of stressor.For the rats in PS group,SEM observation revealed that partial synovium of articular disc began to disintegrate 1 week after psychological stress.Strip-like wear degenerations were shown in the surface collagenous fiber in articular disc 3 weeks later,and the surface collagenous fibers in articular disc were arrayed in disorder 5 weeks following stress treatment.No significant microstructural changes in articular disc were observed in all stressor-eliminating groups and ( PS + DI) group 1,3,and 5 weeks following stress treatment.Statistical significance was noted in RNA expression level of IL-1 between PS group and PS + DI group (P＜0.05).In addition,there was significant difference in IL-1 expression between PS group and all stressor-eliminating groups.Conclusion The implementation of countermeasures effectively counteracted the influence upon TMJ induced by psychological stress,and provided possible resolutions for the clinical treatment of TMD induced by psychological stress.
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Objective To investigate the possible mechanisms of the attribution of psychological stress to the temporomandibular joint disorder(TMD) ,through the evaluation of the animal model and detection of the proinflammatory cytokines in the TMJ.Methods The animal models of communication box were built to mimic the psychological stress.The concentration of the serum Cor and ACTH was detected in the control group, Psychological Stress group ( PS group), and diazepam ( anti-anxiety drug) group ( PS + DI group).The expression of the proinflammatory cytokines IL-1 and IL-6 in the rat TMJ in the different phases of psychologicalstress was detected by RT-PCR.Results The results of the serum concen- tration of Cor and ACTH showed that there was significant difference between the control group and the PS group(P＜0.01 ) ,while no significant difference between the control group and the PS + DI group(P＞0.05).The expressions of IL-1 and IL-6 were comapared in all group.The expressions of IL-1 in CON group were (0.453± 0.021 ) mg/L, (0.439 ± 0.028 ) mg/L and (0.454 ± 0.023 )mg/L.These values were markedly increased compared with those of the PS group(0.981 ±0.024)mg/L, (0.746±0.017)mg/L and (0.510 ±0.016)mg/L respectively, P＜0.01 ) ,but no significant differences compared with PS + DI group(0.549 ± 0.014 ) mg/L, ( 0.498 ± 0.014 ) mg/L and ( 0.444 ± 0.022 ) mg/L respectively, P ＞ 0.05).Similar changes were observed in expressions of IL-6.The expressions of IL-6 in the CON rats were (0.525 ±0.028)mg/L,(0.515 ±0.028)mg/L and (0.518 ±0.022)mg/L,respectively,while those of PS group were(0.820 ± 0.023 ) mg/L, (0.694 ± 0.019 ) mg/L and (0.579 ± 0.015 ) mg/L, respectively, which were significan- tly higher in the PS groups(P＜ 0.05 ).But there were no significant differences between CON group and PS + DI group( (0.599 ±0.015)mg/L, (0.541 ±0.015)mg/L, (0.487 ±0.008)mg/L respectively, P＞0.05).Conclusion The psychological stress can play important role in the formation of TMD.
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Objective To observe the substance P(SP) and calcitonin gene-related peptide(CGRP) expressions in the temporomandibular joints(TM J) of the rats undergone emotional stress and explore the relationship between emotional stress and temporomandibular joint disorder(TMD). Methods Ninety SD rats were averagely randomly divided into emotional stress ( ES ) group( n = 30 ), electric foot-shocked (FS) group ( n = 30 ) and control (CON) group( n = 30). The emotional stress was induced by communication box. The TMJ tissues in ES and CON groups were removed after 1, 3 and 5 weeks of emotional stress for scanning electron microscope ( SEM ) test and immunohistochemistry test. The SP and CGRP expressions were examined with SABC immunohistochemistry and then analyzed by image analysis system. Results The expressions of SP and CGRP had significant difference after 1 ,3 and 5 weeks emotional stress ( SP: 124.5 ± 16.9,185.6 ± 1.8 and 193.5 ± 3.5, respectively; CGRP: 185.9 ±5.3, 112.5 ±5.2 and 174.3 ±5.3 ,respectively) (P＜0. 05 ). The SEM results showed that there was a series of structural change on the condylar surface after emotional stress. Conclusion The SP and CGRP energy nerve fibers take part in the TMJ pathological process undergone emotional stress.
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Objective:To observe the influence of emotional stress on the temporomandibular joint(TMJ) of SD rats. Methods:Standard animal model of emotional stress was created by emotion communication emergency box technique in 30 SD rats and foot-shocked in another 30. Control rats were 30 without treatment. The microstructure and ultrastructure of the disc surface, condylar surface and external pterygoid muscle were observed 1, 3 and 5 weeks after emotional stress treatment. Results:Obviously pathological changes were observed in the experimental animals, especially at 3 weeks, involving the fissures on the disc and condylar surface, the collagen fibers were disordered. Electron microscopy observation showed that condylar collagen was exposed. The mitochondria edema and vacuolar degeneration in the external pterygoid muscle were found.At 5 weeks, the condylar cartilage started to recover. Conclusion:Long term emotional stress may lead to pathological changes of the temporomandibular system. The changes can be partly recovered after a certain time of adaption of TMJ.