At present,the commonly used clinical protocols of oral comestic restoration are mostly based on the aes-thetic indicators proposed by Western developed countries(referred to as Western aesthetics).Mechanically copying the Western aesthetic scheme,ignoring the difference between it and the Chinese oral aesthetic indicators(referred to as Chinese aesthetics),is unable to effectively support personalized cosmetic restoration diagnosis and treatment.In addition,new technologies and new solutions for cosmetic restoration,which are developing rapidly in recent years,are emerging one after another,but many popular concepts are confusing and lack of proper hierarchical diagnosis and treatment norms,and there is indeed an urgent need for discussion and clarity.From the perspective of serving clinical application,this paper discusses the deficiencies of the Chinese translation of the word"aesthetics",the diffe-rence and connection between aesthetics and cosmetolo-gy,and the relationship between cosmetic restoration and fixed restoration.It also discusses the difference be-tween anterior teeth,esthetic zone and exposed zone,the diagnostic and therapeutic value of oral aesthetic analysis,as well as the application methods of desensitization,suggestion,and other therapies in difficult oral cosmetic restoration cases.We further introduce the decision tree and the clinical pathway for restoration and reconstruction of teeth in ex-posed zone guided by aesthetic analysis,and introduce the clinical process of aesthetic analysis and evaluation,the clinical triclassification of oral cosmetic restoration,and the corresponding clinical classification diagnosis and treat-ment points.

At present,the commonly used clinical protocols of oral cosmetic restoration are mostly based on the oral aesthetic indexes proposed by Western developed countries(referred to as Western aesthetics),which are different from the oral aesthetic indexes unique to Chinese people(referred to as Chinese aesthetics).In the design of restoration schemes and the evaluation of restoration effects,these differences have a large or small effect on the doctor-patient-tech-nology triad.Improper handling could directly weaken the cooperation efficiency of the three parties,reduce patient satis-faction,and even lead to medical disputes in serious cases.From doing a good job of oral cosmetic restoration in China,the connotative characteristics of Chinese oral aesthetics are introduced in this paper,and the value of oral aesthetic anal-ysis in diagnosis and treatment is discussed.The process and method of aesthetic analysis and assessment through the modified Chinese psychosocial impact of dental aesthetics questionnaire and the evaluation ruler of the expected value of oral cosmetic restoration are further introduced in detail.

Objective:To investigate the influence of digital light processing (DLP) and computer numerical controlmilling (CNC) on the mechanical behavior of zirconia.Methods:Prepared DLP samples (experimental group, n=52) and CNC samples (control group, n=52) with 12 samples in each group were randomly selected using random number table to measure density, grain size and crystal phase composition. According to the different methods fracture toughness test, the samples were divided into indentation method group (IM) and single-edge-V-notch-beam group (SEVNB), with 30 DLP and 30 CNC samples in IM group, 10 DLP and 10 CNC samples in SEVNB group. The IM group was tested under three different loads (49.03 N, 98.07 N, 196.10 N), there were 10 samples for each load and each sample was tested at 15 points, and the load with the ratio of crack length to indentation diagonal length greater than 2.5 was selected as the indentation load to calculate its IM fracture toughness. At the same time, the SEVNB group was tested with four point bending test to record the maximum load at the time of fracture and calculate the SEVNB fracture toughness. Finally, the indentation and fracture surface were observed using optical microscope and scanning electron microscope, and the results of DLP group and CNC group were further compared to explore the difference in fracture mechanism. Results:The microstructure of DLP and CNC zirconia was basically the same, the density of DLP group was (6.020±0.021) g/cm 3, the grain size was (0.603±0.033) μm; the density of CNC group was (6.038±0.012) g/cm 3, the grain size was (0.591±0.033) μm. Both groups were composed of tetragonal zirconia. The load of 196.10 N was chosen as the indentation load for two groups to calculate the IM fracture toughness. In terms of fracture toughness, there was no significant difference between the two groups ( P>0.05). Scanning electron microscope images of fracture surface showed the intergranular fracture was the leading fracture mode of two groups. The IM and SEVNB fracture toughness of DLP zirconia were (6.111±0.179) MPa·m 1/2 and (7.221±0.809) MPa·m 1/2, respectively. The IM and SEVNB fracture toughness of CNC zirconia were (6.126±0.383) MPa·m 1/2 and (7.408±0.533) MPa·m 1/2, respectively. Conclusions:The microstructure of DLP and CNC zirconia is almost the same, and there is little difference in the fracture toughness of zirconia between two processing technologies.

Objective To evaluate the effect of mild hypothermia combined with hydrogen-rich saline on cerebral injury after cardiac arrest and resuscitation in rats.Methods Healthy male Sprague-Dawley rats,aged 7-8 weeks,weighing 280-320 g,were divided into 5 groups (n=33 each) using a random number table method:sham operation group (group S),cardiac arrest and resuscitation group (group CAR),hydrogen-rich saline group (group H2),mild hypothermia group (group MH),and mild hypothermia plus hydrogen-rich saline group (group MH+H2).Cardiac arrest was induced with transoesophageal cardiac pacing followed by cardiopulmonary resuscitation to establish the cerebral injury model.Hydrogen-rich saline 5 ml/kg was intraperitoneally injected immediately after return of spontaneous circulation (ROSC) in H2 and MH+H2 groups,while the equal volume of normal saline was given instead in the other groups.The body temperature of rats was cooled down to 32-34℃ within 15 min starting from the time point immediately after ROSC and maintained for 4 h in MH and MH+H2 groups.Fifteen rats were selected at 24 h after ROSC to assess the neurological function score (NDS).Eighteen rats in each group were sacrificed at 24 h after ROSC,and brains were removed for microscopic examination of the pathological changes in hippocampal CA1 region after hematoxylin and eosin staining and for determination of pyramidal cell count and expression of glucose-regulated protein 78 (GRP78),C/EBP-homologous protein (CHOP),caspase-12,caspase-3,Bcl-2 and Bax in hippocampal CA1 region (by Western blot).Results Compared with group S,the NDS was significantly decreased,the pyramidal cell count was reduced,the expression of GRP78,CHOP,caspase-12,caspase-3 and Bax was up-regulated,and the expression of Bcl-2 was down-regulated in the other four groups (P＜0.05).Compared with group CA-R,the NDS and pyramidal cell count were significantly increased,the expression of GRP78 and Bcl-2 was up-regulated,and the expression of CHOP,caspase-12,caspase-3 and Bax was down-regulated in H2,MH and MH+H2 groups (P＜0.05).Compared with group H2 or group MH,the NDS and pyramidal cell count were significantly increased,the expression of caspase-3 and Bax was down-regulated,the expression of Bcl-2 was up-regulated (P＜0.05),and no significant change was found in the expression of GRP78,CHOP and caspase-12 in group MH+H2 (P＞ 0.05).Conclusion Combination of mild hypothermia and hydrogen-rich saline offers enhanced efficacy in reducing cerebral injury after cardiac arrest and resuscitation over mild hypothermia or hydrogen-rich saline alone in rats.

Objective To evaluate the effects of hydrogen-rich saline on the expression of miR-210 and miR-21 in hippocampus during global cerebral ischemia-reperfusion (I/R) in rats.Methods Seventy-two healthy male Sprague-Dawley rats,aged 9-10 weeks,weighing 250-300 g,were randomly divided into 3 groups (n =24 each):sham operation group (group S),group I/R,and hydrogen-rich saline group (group H).Global cerebral I/R was produced by 4-vessel occlusion method.In group H,0.6 mmol/L hydrogen-rich saline 5 ml/kg was injected intraperitoneally at 0 and 6 h of reperfusion,while the equal volume of normal saline was injected instead of hydrogen-rich saline in the other two groups.Rats were sacrificed at 24 and 72 h of reperfusion,and then the bilateral hippocampi were removed for detection of the expression of miR-210 and miR-21 using RT-PCR.The global brain tissues were also obtained and stained with HE for examination of the changes in pyramidal cells in the CA1 region of hippocampus.Results Compared with group S,the expression of miR-210 and miR-21 was significantly up-regulated,and the number of pyramidal cells was decreased in group I/R (P ＜ 0.05).Compared with group I/R,the expression of miR-210 and miR-21 was significantly down-regulated,and the number of pyramidal cells was increased in group H (P ＜ 0.05).The pathological changes were significantly ameliorated in group H.Conciusion The mechanism by which hydrogen-rich saline attenuates global cerebral I/R injury is related to downregulation of the expression of miR-210 and miR-21 in rat hippocampus.

ObjectiveTo evaluate the effect of hydrogen-rich saline given during reperfusion on global cerebral ischeraia-reperfusion (I/R) injury in rats.Methods Seventy-two adult male SD rats,aged 2.0-2.5 months,weighing 260-300 g,were randomly divided into 3 groups (n ＝ 24 each):sham operation group (group S),group I/R and hydrogen-rich saline group (group H).In groups I/R and H cerebral I/R was induced by occlusion of 4 vessels( cauterization of bilateral carotid arteries and 15 min occlusion of bilateral common carotid arteries).In group H intraperitoneal 0.6 mmol/L hydrogen-rich saline 5 ml/kg was injected at 6 h of reperfusion,while equal volume of normal saline was injected instead of hydrogen-rich saline.Eighteen rats of each group were sacririced at 24 h of reperfusion,and then the hippocampi were removed for determination of malondialdehyde (MDA),tumor necrosis factor-α (TNF-α),interleukin-6 (IL-6)contents,and nuclear factor-κB (NF-κB) activity and activated caspase-3 expression.Another six rats of each group were sacrificed at 72 h of reperfusion,and then brain tissues were removed for microscopic examination and counting the number of uninjured pyramidal cells in hippocampal CA1 region.ResultsCompared with S group,the contents of MDA,TNF-α,IL-6 and NF-κB activity were significantly increased,activated caspase-3 expression was significantly up-regulated,uninjured pyramidal cells in hippocampal CA1 region were significantly decreased in I/R group( P < 0.05).Hydrogen-rich saline given during reperfusion attenuated the above-mentioned I/R-induced changes( P < 0.05 ).The histologic damage of the hippocampal CA1 region was significantly slighter in group H than group I/R.ConclusionHydrogen-rich saline given during reperfusion can reduce global cerebral I/R injury in rats through inhibition of lipid peroxidation,inflammatory response and apoptosis.

Objective To investigate the role of mitochondrial permeability transition pore (mPTP) of hippocampal neurons in process of hydrogen-rich saline attenuating global cerebral ischemia-reperfusion (I/R) injury in rats.Methods Seventy-two male Sprague Dawley rats,weighing 250-300 g,were randomly divided into six groups ( n =12 each):sham operation group (group S),cerebral ischemia-reperfusion group (group IR),normal saline group (group NS),hydrogen-rich saline group (group H),atractyloside group (group A) and hydrogen-rich saline + atractyloside group (group HA).Global cerebral I/R injury was produced by four-vessel occlusion method.Bilateral vertebral arteries were cauterized.Then bilateral common carotid arteries were occluded for 15min and followed by reperfusion.In groups H and HA,hydrogen-rich saline 5 ml/kg was injected intraperitoneally immediately after reperfusion,while equal volume of normal saline was injected in the other four groups.The rats in groups A and HA received intracerebroventricular injection of atractyloside 15 μl 10 min before reperfusion,while groups NS and H received intracerebroventricular injection of equal volume of normal saline.After the neurological behavior was evaluated at 24 h of reperfusion,8 rats in each group were sacrificed and the hippocampi were immediately isolated and homogenized followed by density gradient centrifugation.The opening degree of mPTP was assayed with spectrophotometry and the mitochondrial membrane potential (MMP) was detected with Rhodamine 123 method.Four rats in each group were killed at 72 h of reperfusion and the brains were removed for microscopic examination of the area CA1 of the hippocampus and determination of the number of normal pyramidal neurons.Results Compared with group S,the neurological behavior was compromised,MMP was decreased and mPTP opening degree was enhanced in the other five groups ( P ＜ 0.05).The neurological behavior was better,MMP was increased and mPTP opening degree was decreased in groups H and HA as compared with group IR ( P ＜ 0.05).Compared with group H,the neurological behavior was compromised,MMP was decreased and mPTP opening degree was enhanced in group HA ( P ＜ 0.05).Compared with group IR,the number of normal pyramidal neurons at 72 h of reperfusion in the CA1 region of the hippocampus was higher in group HA ( P ＜0.05).The injury of the CA1 region of the hippocampus at 72 h of reperfusion was attenuated in group H as compared with groups IR,NS,A and HA.Conclusion Hydrogen-rich saline can attenuate global cerebral I/R injury throngh inhibiting the mPTP opening and reducing the dissipation of MMP,thus maintaining the mitochondrial function.

Objective To investigate the role of A2B adenosine receptor(A2BAR)in 6% HES 130/0.4-induced reduction of pulmonary capillary permeability in a rat model of sepsis.Methods Fifty male SD rats weighing 250-300 g were randomly divided into 5 groups(n = 10 each): group Ⅰ sham operation(group S);group Ⅱ sepsis(group CLP);group Ⅲ ,Ⅳ,Ⅴ low,medium,high dose HES(group H1,2,3).The animals were anesthetized with intraperitoneal pentobarbital sodium 50 mg/kg.Left carotid artery and left femoral vein were cannulated for MAP and HR monitoring and fluid and drug administration.Sepsis was induced by cecal ligation and puncture (CLP).6% HES 130/0.4 7.5,15.0 and 30.0 ml/kg were infused iv over 2 h in group H1,2,3 respectively at 4 h after CLP.The animals were sacrificed at 6 h after CLP.The lungs were isolated for determination of pulmonary capillary permeability(by iv Evans blue injection),the expression of A2BAR and the contents of cAMP,protein kinase A(PKA),TNF-α,IL-6 and IL-10 in the lung tissue.Results CLP significantly increased pulmonary capillary permeability,A2BAR expression and cAMP,IL-6 and TNF-α contents in the lung tissue in group Ⅱ as compared with group S.0.6% HES 130/0.4 significantly reduced pulmonary capillary permeability,increased A2BAR expression,cAMP,PKA and IL-10 and decreased IL-6 and TNF-αcontents in the lung tissue in group H1,2,3 as compared with group CLP.6% HES 130/0.4 decreased pulmonary capillary permeability and up-regulated A2BAR expression in a dose-dependent manner.6% HES 130/0.4 15.0 ml/kg was most effective in increasing cAMP and PKA contents in the lung and depressing inflammatory response.Conclusion 6% HES 130/0.4 decreases pulmonary capillary permeability in a rat model of sepsis by up-regulating A2BAR expression in lung tissue.

Objective To investigate the effect of gabapentin on high voltage active calcium currents in the injured dorsal root ganglion (DRG) neurons in a rat model of neuropathic pain.Methods Pathogen-free male SD rats aged 4-6 weeks were used in this study. The animals were anesthetized with intraperitoneal pentobarbital soclium 50 mg/kg. L_5 spinal nerve was ligated between DRG and sciatic nerve and cut distal to the ligature. The animals were decapitated on the 14th postoperative day. L_5 DRG was isolated and the neurons in the ganglion were enzymatically dissociated. The high voltage active calcium current was recorded using whole-cell patch-clamp technique.Results Gabapentin inhibited the peak calcium current in the injured DEG neurons. Peak calcium current was decreased by gabapentin 100 μmol/L and both activation and steady-state inactivation curve shifted to more hyperpolarized potentials. Conclusion Gabapentin can inhibit high voltage active in the injured DRG neurons in a rat model of neuropathic pain. The alteration in the inactivation of the electrophysiological properties may be involved in the mechanism.

Objective To investigate the changes in high voltage-activated (HVA) calcium current in dorsal root ganglion (DRG) neurons isolated from rats with neuropathic pain. Methods Pathogen-free male SD rats aged 4-6 weeks weighing 180-220 g were used in this study. The animals were anesthetized with intraperitoneal pentobarbital sodium 50 mg/kg. Neuropathic pain was induced by ligation of L5 spinal nerve between DRG and sciatic nerve. The nerve was transected distal to the ligature. The animals which showed positive signs of neuropathic pain were decapitated on the 14th postoperative day. L5 and L4 DRGs were isolated and the neurons in the ganglia were enzymatically dissociated (group L5 and L4). The control group received no surgery (group C). The HVA Ca2+ current was recorded using whole-cell patch clamp technique. Results Peak calcium current density was significantly lower in group L5 and L4 than in group C, and was significantly lower in group L5 than in group L4 . Halfactivation value (Va 1/2) was also significantly lower in group L5 than in group C and L4 (P ＜ 0.05). The relative contribution of N-type to the total HVA Ca2+ current was significantly greater in group L5 than in group C and L4(P ＜ 0.05). There was no significant difference in the steady-state inactivation curves among the 3 groups. Conclusion In rats with neuropathic pain, the HVA Ca2+ current in the injured DRG neurons may play a key role in the induction of neuropathic pain.