Objective: To study the effect of different wetness degrees in the root canal on the canal sealing. Methods: 160 root canal prepared single rooted teeth were divided into 4 groups (n = 40) by the root canal wetness degree (water content, V): (1) 0. 250 ～0. 299, (2) 0. 300 ～ 0. 599, (3) 0. 600 ～ 0. 899 and (4) 0. 900 ～ 1. 199 respectively. 80 teeth were divided into 4 groups (n = 20) for dye leakage test and another 80 for bacterial microleakage test. Zinc oxide paste (ZOP) and AH-Plus (AH-P) with vertical condensation of warm gutta-percha were respectively used to seal the canals in each group of the samples (n = 10) . The length of in vitro tooth dye penetration was measured by stereomicroscope; the time (days) of turbidity in the bacterial leakage model observed and compared. Results: Of all the canals sealed by ZOP or AH-P with the increase of the wetness the dye infiltration length increased significantly (P ＜0. 05) and the days in which the faecal intestine ball infiltrated into the lower chamber of the model was gradually decreased (P ＜0. 05) . Conclusion: The increase of root canal moisture may reduce the sealing of the root canal.

Optimization of sedation depth has become one of hot spots for critical care medicine research.Previous multiple studies have demonstrated that deep sedation is associated with poor outcomes in patients with mechanical ventilation.But unnecessary deep sedation remained not rare in our clinical practices owing to complex reasons (partially unknown).Maintaining light rather than deep sedation stragey for patients with mechanical ventilation,therefore,was highly recommended.Meanwhile,it was concerned that the depth of sedation was probably proscribed inappropriately in some of lightly sedated patients largely due to lack of well-predefined contraindications,which even likely increased risk of adverse events in our clinical practices.In addition,increasing publications updated the impacts of analgesia/sedation on immune,gastrointestinal and neural-muscular function in the patients with chronic critical illness,a highly concerned critically ill population.Based on available data,less sedatives and opioids were suggested for these patients.Moreover,eCASH concept,a patient-centered,adequate analgesia and light sedation based and humanistic care strengthened comprehensive management strategy was currently proposed to improve the long-term outcomes for patients with mechanical ventilation.It provided us valuable information,in either optimization of clinical practices or research interests,on promoting our medical behaviors and cognition in order to improve patient comfort,safety and clinical outcomes.However,future high-quality clinical researches are needed to verify its feasibility and validity.

Objective To biomechanically study the fixation stability of different numbers and shapes of the titanium miniplates (L-shaped and straight four-hole miniplates) in the treatment of maxillary LeFortⅠ fracture by using three-dimensional finite element method so as to provide reference for clinical treatment of the fractures. Methods Three-dimensional finite element model of maxillary LeFortⅠ fracture was established with four kinds of rigid internal fixation (RIF) methods to calculate the stress of the maxilla and the RIF as well as the displacement of the fracture segment under three kinds of occlusion.Then, the fixation stability of different methods was compared. Results Under the same occlusion condition, the decreasing order of the displacement of the fracture segment was the L-shaped plate fixation at both buttress of the maxillary and nasal maxillary zygomatic, the straight four-hole miniplates fixation at both buttress of the maxillary and nasal maxillary zygomatic, the L-shaped plate fixation at the zygomatic maxillary buttress and the L-shaped plate fixation at naso-maxillary buttress. Under the same fixation method, the decreasing order of the displacement of the fracture segment was molar occlusion, premolar oeclusion and incisor occlusion. Conclusions The fixation stability of the L-shaped plate fixation is better than the straight four-hole miniplate fixation for the treatment of LeFortⅠ fracture. Fixation at the zygomaticmaxillary buttress is better than at the naso-maxillary buttress. Use of only two miniplates to fix the LeFort Ⅰ fracture may not be stable. Molar occlusion is not good for fracture healing.

Objective To set up the 3D-finite element(FE)model of normal acetabulum-cartilage-femoral head,so that to provide an effective model for biomechanical analysis of femoral head.Methods(1)The hip joint in one healthy adult male volunteer was scanned by MRI at coronal section.The 3D reconstruction model of acetabulum-cartilage-femoral head was constructed with MATLAB and ANSYS software.(2)The 3D orthotropy finite element model of the acetabulum-cartilage-femoral head was constructed by givig the corresponding material parameters to the different structures of the model of acetabulum-cartilage-femoral head and divided into networks through ANSYS software.(3)The standing status was imitated on the model to set boundary condition and loading and then calculated.The effect of the model was evaluated in comparison with that of literature.Results A 3D orthotropy FE model of acetabulum-cartilage-femoral head was established successfully,including 89 961 points of 448 159 units.The maximal displacement was on the femoral head,and the maximal Von Mises stress was on the femur neck.The stress analysis was the same as the results of literature and the actuality.Conclusion A 3D orthotropy FE model of acetabulum-cartilage-femoral head can be setup based on MRI images,which can provide a reasonable and effective model for biomechamical analysis of femoral head.

Objective To analyze the causes of rhabdomylysis (RM), pathogenetic mechanisms and possible effective interventions for secondary multiple organ dysfunction syndrome (MODS) caused by RM. Methods causes of RM, clinical manifestations, severity of disease evaluated by APACHE Ⅱ and Marshall MODS Score, results of laboratory, clinical interventions and outcome were analyzed in all three MODS cases secondary to RM. Results The specific causes of RM were not clear. However, persistent acute twitch and hyperthermia occurred very early in all three cases. Plasma CK was increased 50 fold over the normal level. Number of injured organs was 7, 4 and 6, respectively. Marshall MODS score ranged from 15 to 21. APACHE Ⅱ scores were greater than 20 in all cases. One patients survived, the other two died. CRRT started early had been shown to be beneficial to decrease the markedly elevated plasma CK, CK-Mb, ALT, ALT and LDH. Conclusion Although the mechanism of RM with secondary MODS has not been elucidated yet, deep sedation as well as effective hypothermia to control acute twitch and hyperthermia should be the essential interventions to attenuate further organ injury. Additionally, based on effective advanced life support, CRRT started early could be an important therapy for MODS secondary to RM.

Objective:To study the stress distribution dur i ng clenching and rigid internal fixation(RIF)of mandibular symphysis fracture. Methods:ANSYS software was used to establish the models of mandi bular symphysis fracture and the fracture treatment treat with RIF.The stress di stribution of mandibular symphysis fracture under different conditions were then analysed during different period of bone healthing. The value of stress shieldi ng rate was used to represent the level of stress shielding effects.Resu lts:The stress shielding rate decreased with the progression of fracture healing.The stress shielding rate produced by double plates fixation was higher than that by single plate.Stress shielding rate in the mandible fixed with tita nium plate was lower than that with steel plate.Conclusion:Minip late rigid internal fixation system may produce stress shielding effects when it is used to treat mandibular symphysis fractures. Stress shielding effects are a ffected by the attribute, the shape and the position of the plate.