Objective To investigate the pathological changes and mechanism in the urethra by parturition-induced stress urinary incontinence.Methods Sprague Dawley female rats underwent vaginal balloon dilation for 4 hours immediately after delivery.One week later,the rats were anesthetized and both ovaries were excised.Then a rat model of stress urinary incontinence (SUI) was successfully established.One month after ovariectomy,conscious cystometry and Leak-Point Pressure (LPP) were measured by MP150.Histological examination and Western blotting were performed after functional assays.Results (1) 85％ of rats presented astress urinary incontinence in the model group.(2) The urethras in SUI rats had decreased muscles,and striated muscles showed fragmentized and disorganized.(3) Elastic fibers were long,well organized and tightly connected to the muscle bundles in sham group,while elastic fibers showed fragmentation and disorganization in the model group.(4) The protein expression of vascular endothelial growth factor (VEGF) and blood vessels were reduced in SUI rats as compared with the sham rats.Conclusions Muscle and elastic fibers in the urethra are disrupted in SUI rat.VEGF may play an important role in regulation of pathological changes in urethra.

Objective To explore the safety and efficacy of dezocine combined with flurbiprofen axetil in postoperative analgesia in elderly patients undergoing upper abdominal surgery.Methods 80 patients underwent abdominalsurgery were selected.They were divided into study group(T group) and control group(C group) according to the random number table,40 cases in each group.The visual analogue scale(VAS) and Ramsay sedation score were recorded at 2h,6h,12h,24h,48h after operation,respectively.The anesthesia-related complications such as sleepiness,chills,postoperative nausea and vomiting (PONV),and pulmonary infection in 48 hours were also recorded.Results There were no statistically significant differences in the VAS score between the two groups in the resting state and the active state(t =0.287,0.436,all P ＞ 0.05).The VAS scores of T group were significantly lower than those of C group at 2h,6h,12h,24h and 48h after operation (t =4.096,4.241,5.510,6.121,5.752,3.542,3.866,4.948,5.542,4.030,all P ＜ 0.05).There were no statistically significant differences in Ramsay sedation scores between the two groups at postoperative 2h,6h,12h,24h and 48h (t =0.323,0.226,0.541,0.297,0.771,0.795,all P ＞ 0.05).There were no statistically significant differences in the incidence of drowsiness,chills,PONV,skin itching and pulmonary infection in the two groups (4 cases vs.6 cases,6 cases vs.5 cases,5 cases vs.3 cases,1 case vs.3 cases,5 cases vs.1 case,P =0.499,0.712,0.745,0.615,0.201).Conclusion The postoperative analgesic compatibility of dezocine combined with flurbiprofen axetil can effectively relieve the postoperative pain in elderly patients with upper abdominal surgery and provide good postoperative analgesic effect and does not increase the incidence of drug related complications.It is worth to promote in clinical.

Objective To compare the effects of general anesthesia and epidural block anesthesia on postoperative short-term cognitive function of elderly orthopedic patients.Methods From January 2015 to March 2013,80 elderly patients with orthopedic surgery in the Sixth Hospital of Ningbo were selected in the research ,According to the anes-thesia method,40 patients received general anesthesia were enrolled into general anesthesia group ,40 patients received epidural anesthesia were enrolled into epidural group.The cognitive function of different time were compared between the two groups.Results There were no statistically significant differences in blood pressure and heart rate between the two groups (all P＞0.05).The simple mental health scale (MMSE) scores at 6h,12h,24h after anesthesia in the general anesthesia group were (26.4 ±0.7)points,(25.9 ±0.5)points,(29.2 ±0.8)points,respectively,compared with that before anesthesia[(29.1 ±1.1)points],the difference was statistically significant (t＝6.235,P＜0.05). The MMSE scores at 6h,12h after anesthesia in the epidural group were (26.5 ±0.4) points,(25.8 ±0.7) points, compared with that before anesthesia[(29.2 ±0.8)points],the difference was statistically significant (t＝5.123, P＜0.05).The MMSE score at 24 h after anesthesia in the epidural group was (29.5 ±0.7)points,which was obvi-ously higher than (27.2 ±0.8)points in the general anesthesia group (t＝13.684,P＜0.05).The incidence rates of postoperative cognitive dysfunction (POCD) at 6h,12h after anesthesia in the general anesthesia group (17.50%, 20.00%) were significantly higher than those in the epidural group (7.50,5.00%) ( χ2＝4.571,10.285,all P＜0.05).Conclusion The effect of general anesthesia on postoperative cognitive function is significantly greater than that of epidural anesthesia.

OBJECTIVETo reconstruct the centric relation of upper and lower edentulous dental models with two methods, to compare the reconstruction accuracy of the vertical and horizontal distance, and to provide some references to computer aided design and computer aided manufacture for complete denture.

METHODSDental models and rims made from five edentulous patients in clinical were obtained.Each model was stocked with 10 identical size positioning cylinders (20 cylinders on each pair models) on 5 side-surfaces of basement. Twelve center point pairs were paired between upper and lower models from 20 cylinder bottoms. The vertical and horizontal distances of 12 center point pairs were regarded as the evaluation items. Firstly, upper and lower models and rims were scanned separately. Then, models and rims (fixed in centric relation respectively with positioning articulator and rubber banding) were scanned.In software, all the data were registered to reconstruct centric relation based on common region. Digital models were measured with software tools, and real models were measured with a contact measurement arm. The differences of the homologous items between two methods were analyzed with paired-t test.

RESULTSThe vertical distance errors for dental articulator positioning method was (0.356 ± 0.200) mm and that of the rubber band method was (0.382 ± 0.299) mm, and paired-t test between the two methods showed no significant differences (P > 0.05). The horizontal errors were (0.010 ± 0.411) mm and (0.104 ± 0.476) mm, and paired-t test showed significant differences (P < 0.05).

CONCLUSIONSComparing with rubber band method, dental articulator positioning can significantly increases three-dimensional reconstruction accuracy of edentulous jaw gypsum models' horizontal relation.

Centric Relation ; Computer-Aided Design ; Dental Articulators ; Dental Models ; Denture, Complete ; Humans ; Image Processing, Computer-Assisted ; Jaw, Edentulous ; Mouth, Edentulous ; Software ; Tomography, X-Ray Computed

The successful research and application of robotic techniques will promote more dental practitioners to operate robotic simulation systems in various aspects as clinical practice, teaching and scientific research. This paper reviews the history and development of dental robotics in a systematic way. We specifically introduce the application conditions and estimate the future development of dental robotics. Besides, we also foresee the potential impact and change brought by dental robotic techniques.

Objective: To compare the clinical effects of urokinase thrombolytic therapy for optic artery occlusion (OAO) and retinal artery occlusion (RAO) caused by facial microinjection with hyaluronic acid and spontaneous RAO. Methods: From January 2014 to February 2018, 22 eyes of 22 patients with OAO and RAO caused by facial microinjection of hyaluronic acid who received treatment in Xi'an Fourth Hospital were enrolled in this retrospective study (hyaluronic acid group). Twenty-two eyes of 22 patients with spontaneous RAO were selected as the control group. The BCVA examination was performed using the international standard visual acuity chart, which was converted into logMAR visual acuity. FFA was used to measure arm-retinal circulation time (A-Rct) and filling time of retinal artery and its branches (FT). Meanwhile, MRI examination was performed. There were significant differences in age and FT between the two groups (t=14.840, 3.263; P=0.000, 0.003). The differecens of logMAR visual acuity, onset time and A-Rct were not statistically significant between the two groups (t=0.461, 0.107, 1.101; P=0.647, 0.915, 0.277). All patients underwent urokinase thrombolysis after exclusion of thrombolytic therapy. Among the patients in the hyaluronic acid group and control group, there were 6 patients of retrograde ophthalmic thrombolysis via the superior pulchlear artery, 6 patients of retrograde ophthalmic thrombolysis via the internal carotid artery, and 10 patients of intravenous thrombolysis. FFA was reviewed 24 h after treatment, and A-Rct and FT were recorded. Visual acuity was reviewed 30 days after treatment. The occurrence of adverse reactions during and after treatment were observed. The changes of logMAR visual acuity, A-Rct and FT before and after treatment were compared between the two groups using ttest. Results: At 24 h after treatment, the A-Rct and FT of the hyaluronic acid group were 21.05±3.42 s and 5.05±2.52 s, which were significantly shorter than before treatment (t=4.569, 2.730; P=0.000, 0.000); the A-Rct and FT in the control group were 19.55±4.14 s and 2.55±0.91 s, which were significantly shorter than before treatment (t=4.114, 7.601; P=0.000, 0.000). There was no significant difference in A-Rct between the two groups at 24 h after treatment (t=1.311, P=0.197). The FT difference was statistically significant between the two groups at 24 h after treatment (t=4.382, P=0.000). There was no significant difference in the shortening time of A-Rct and FT between the two groups (t=0.330, 0.510; P=0.743, 0.613). At 30 days after treatment, the logMAR visual acuity in the hyaluronic acid group and the control group were 0.62±0.32 and 0.43±0.17, which were significantly higher than those before treatment (t=2.289, 5.169; P=0.029, 0.000). The difference of logMAR visual acuity between the two groups after treatment was statistically significant (t=2.872, P=0.008). The difference in logMAR visual acuity before and after treatment between the two groups was statistically significant (t=2.239, P=0.025). No ocular or systemic adverse reactions occurred during or after treatment in all patients. Conclusions Urokinase thrombolytic therapy for OAO and RAO caused by facial microinjection with hyaluronic acid and spontaneous RAO is safe and effective, with shortening A-Rct, FT and improving visual acuity. However, the improvement of visual acuity after treatment of OAO and RAO caused by facial microinjection with hyaluronic acid is worse than that of spontaneous RAO.

Objective: To analyze the quantitative relationship between the number of layers of laser pulses and the amount of step in ultra-short pulse laser cutting of cortical bone, optimize the robot's vertical single stepping parameters, and to explore the feasibility of automatic preparation of dental implant cavity using robot controlling ultra-short pulse laser, in order to lay the foundation for automated dental implant surgery. Methods: Eight pig ribs were segmented into to make 16 specimens. Using the robotic surgical system and path planning software independently developed by our group, circular holes with a diameter of 4 mm were cut two-dimensionally in the rib segments to obtain the quantification relationship of the number of laser pulse layers (n) and the depth of two-dimensional (2D) cutting (d). When conducting the three-dimensional (3D) cutting procedure, the number of pulse layers were set to 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 layers, the vertical single step amount was an integer value corresponding to the results of 2D cutting depth, and the number of pulses (n') corresponding to the minimum difference between the theoretical depth of cut and the actual depth of cut was obtained. The n' was taken as the most suitable single step pulse layer, the rib segment was cut, and the depth of single cut was measured while the integer value was taken as the most appropriate vertical single step amount (d'). The vertical parameters of laser single stepping were set as n' layer pulse and d′ μm step size. The 3D cutting produces a cylindrical cavity with a diameter of 4 mm and a height of 2 mm to evaluate the 3D cutting accuracy (the difference between the measured value and the theoretical value of cutting diameter or depth). Ten 4 mm×3 mm implant holes were automatically prepared on the bilateral femurs of 5 Japanese big white rabbits, and ten 4 mm×3 mm implants made by 3D printer were artificially implanted, and the preparation effect of the implant cavities was evaluated. Results: The quantitative relationship curve between the number of laser pulses (n) and 2D depth of cut (d) showed a linear upward trend. The linear fitting obtained the quantitative relation function formula d=9.278 4 n±26.763 0, R²=0.988 9. The optimum number of single step pulse layers was 5 layers, and the vertical single step amount was 50 μm, so as to set the vertical parameters of a single step of a 3D cutting, and the 3D cutting diameter accuracy was (3.98±2.87) μm, with a depth accuracy of (15.42±5.44) μm. Automated preparation of 10 implant cavities on the femur of the rabbit were completed. When the implants were placed into the implant cavities, there was resistance, but they were fully seated and primary stability has been achieved after seating implant placement. Conclusions The method of non-contact automatic preparation of dental implant cavities using robot controlling ultra-short pulse laser is feasible. By optimizing the single cutting process parameters, precise control of laser cutting cortical bone can be realized.

Objective: To further study the most suitable parameters for automatic full crown preparation using oral clinical micro robot. Its purpose is to improve the quality of automated tooth preparing for the system and to lay the foundation for clinical application. Methods: Twenty selected artificial resin teeth were used as sample teeth. The micro robot automatic tooth preparation system was used in dental clinic to control the picosecond laser beam to complete two dimensional cutting on the resin tooth sample according to the motion planning path. Using the laser scanning measuring microscope, each layer of cutting depth values was obtained and the average value was calculated. The monolayer cutting depth was determined. The three-dimensional (3D) data of the target resin teeth was obtained using internal scanner, and the CAD data of full-crown tooth preparation was designed by CAD self-develged software. According to the depth of the single layer, 11 complete resin teeth in phantom head were automatically prepared by the robot controlling the laser focused spot in accordance with the layer-cutting way. And the accuracy of resin tooth preparation was evaluated with the software. Using the same method, monolayer cutting depth parameter for cutting dental hard tissue was obtained. Then 15 extracted mandibular and maxillary first molars went through automatic full crown tooth preparation. And the 3D data of tooth preparations were obtained with intra oral scanner. The software was used to evaluate the accuracy of tooth preparation. Results: The results indicated that the single cutting depth of cutting resin teeth and in vitro teeth by picosecond laser were (60.0±2.6) and (45.0±3.6) μm, respectively. Using the tooth preparation robot, 11 artificial resin teeth and 15 complete natural teeth were automatically prepared, and the average time were (13.0±0.7), (17.0±1.8) min respectively. Through software evaluation, the average preparation depth of the occlusal surface of 11 resin teeth was approximately (2.089±0.026) mm, the error was about (0.089±0.026) mm; the average convergence angle was about 6.56°±0.30°, the error was about 0.56°±0.30°. Compared with the target preparation shape, the average shape error of the 11 resin tooth preparations was about 0.02-0.11 mm. And the average preparation depth of the occlusal surface of 15 natural teeth was approximately (2.097±0.022) mm, the error was about (0.097±0.022) mm; the average convergence angle was about 6.98°±0.35°, the error was about 0.98°±0.35°. Compared with the target preparation shape, the average shape error of the 15 natural tooth preparations was about 0.05-0.17 mm. Conclusions The experimental results indicate that the automatic tooth preparation for resin teeth and the teeth were completed according to the specific parameters of the single cutting depth by the micro robot controlling picosecond laser respectively, its preparation accuracy met the clinical needs. And the suitability of the parameter was confirmed.