1.Expert consensus on apical microsurgery.
Hanguo WANG ; Xin XU ; Zhuan BIAN ; Jingping LIANG ; Zhi CHEN ; Benxiang HOU ; Lihong QIU ; Wenxia CHEN ; Xi WEI ; Kaijin HU ; Qintao WANG ; Zuhua WANG ; Jiyao LI ; Dingming HUANG ; Xiaoyan WANG ; Zhengwei HUANG ; Liuyan MENG ; Chen ZHANG ; Fangfang XIE ; Di YANG ; Jinhua YU ; Jin ZHAO ; Yihuai PAN ; Shuang PAN ; Deqin YANG ; Weidong NIU ; Qi ZHANG ; Shuli DENG ; Jingzhi MA ; Xiuping MENG ; Jian YANG ; Jiayuan WU ; Yi DU ; Junqi LING ; Lin YUE ; Xuedong ZHOU ; Qing YU
International Journal of Oral Science 2025;17(1):2-2
Apical microsurgery is accurate and minimally invasive, produces few complications, and has a success rate of more than 90%. However, due to the lack of awareness and understanding of apical microsurgery by dental general practitioners and even endodontists, many clinical problems remain to be overcome. The consensus has gathered well-known domestic experts to hold a series of special discussions and reached the consensus. This document specifies the indications, contraindications, preoperative preparations, operational procedures, complication prevention measures, and efficacy evaluation of apical microsurgery and is applicable to dentists who perform apical microsurgery after systematic training.
Microsurgery/standards*
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Humans
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Apicoectomy
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Contraindications, Procedure
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Tooth Apex/diagnostic imaging*
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Postoperative Complications/prevention & control*
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Consensus
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Treatment Outcome
2.Expert consensus on difficulty assessment of endodontic therapy
Huang DINGMING ; Wang XIAOYAN ; Liang JINGPING ; Ling JUNQI ; Bian ZHUAN ; Yu QING ; Hou BENXIANG ; Chen XINMEI ; Li JIYAO ; Ye LING ; Cheng LEI ; Xu XIN ; Hu TAO ; Wu HONGKUN ; Guo BIN ; Su QIN ; Chen ZHI ; Qiu LIHONG ; Chen WENXIA ; Wei XI ; Huang ZHENGWEI ; Yu JINHUA ; Lin ZHENGMEI ; Zhang QI ; Yang DEQIN ; Zhao JIN ; Pan SHUANG ; Yang JIAN ; Wu JIAYUAN ; Pan YIHUAI ; Xie XIAOLI ; Deng SHULI ; Huang XIAOJING ; Zhang LAN ; Yue LIN ; Zhou XUEDONG
International Journal of Oral Science 2024;16(1):15-25
Endodontic diseases are a kind of chronic infectious oral disease.Common endodontic treatment concepts are based on the removal of inflamed or necrotic pulp tissue and the replacement by gutta-percha.However,it is very essential for endodontic treatment to debride the root canal system and prevent the root canal system from bacterial reinfection after root canal therapy(RCT).Recent research,encompassing bacterial etiology and advanced imaging techniques,contributes to our understanding of the root canal system's anatomy intricacies and the technique sensitivity of RCT.Success in RCT hinges on factors like patients,infection severity,root canal anatomy,and treatment techniques.Therefore,improving disease management is a key issue to combat endodontic diseases and cure periapical lesions.The clinical difficulty assessment system of RCT is established based on patient conditions,tooth conditions,root canal configuration,and root canal needing retreatment,and emphasizes pre-treatment risk assessment for optimal outcomes.The findings suggest that the presence of risk factors may correlate with the challenge of achieving the high standard required for RCT.These insights contribute not only to improve education but also aid practitioners in treatment planning and referral decision-making within the field of endodontics.
3.Expert consensus on irrigation and intracanal medication in root canal therapy
Zou XIAOYING ; Zheng XIN ; Liang YUHONG ; Zhang CHENGFEI ; Fan BING ; Liang JINGPING ; Ling JUNQI ; Bian ZHUAN ; Yu QING ; Hou BENXIANG ; Chen ZHI ; Wei XI ; Qiu LIHONG ; Chen WENXIA ; He WENXI ; Xu XIN ; Meng LIUYAN ; Zhang CHEN ; Chen LIMING ; Deng SHULI ; Lei YAYAN ; Xie XIAOLI ; Wang XIAOYAN ; Yu JINHUA ; Zhao JIN ; Shen SONG ; Zhou XUEDONG ; Yue LIN
International Journal of Oral Science 2024;16(1):26-35
Chemical cleaning and disinfection are crucial steps for eliminating infection in root canal treatment.However,irrigant selection or irrigation procedures are far from clear.The vapor lock effect in the apical region has yet to be solved,impeding irrigation efficacy and resulting in residual infections and compromised treatment outcomes.Additionally,ambiguous clinical indications for root canal medication and non-standardized dressing protocols must be clarified.Inappropriate intracanal medication may present side effects and jeopardize the therapeutic outcomes.Indeed,clinicians have been aware of these concerns for years.Based on the current evidence of studies,this article reviews the properties of various irrigants and intracanal medicaments and elucidates their effectiveness and interactions.The evolution of different kinetic irrigation methods,their effects,limitations,the paradigm shift,current indications,and effective operational procedures regarding intracanal medication are also discussed.This expert consensus aims to establish the clinical operation guidelines for root canal irrigation and a position statement on intracanal medication,thus facilitating a better understanding of infection control,standardizing clinical practice,and ultimately improving the success of endodontic therapy.
4.Effect and mechanism of VSIG4 gene mutation on the function of microglia in retinitis pigmentosa
Chunlong XU ; Guowei ZHANG ; Jun DU ; Zhen JIA ; Jingping WANG ; Ziwen WANG ; Yang LI ; Hong LU
Chinese Journal of Experimental Ophthalmology 2024;42(10):898-908
Objective:To investigate the effect and mechanism of the V-set and immunoglobulin domain-containing 4 ( VSIG4 ) gene mutation on the function of microglia in retinitis pigmentosa (RP). Methods:Localization of VSIG4 in the retina was detected by immunofluorescence.HMC3 cells (human microglial cells) were transfected with wild-type (Len-WT) VSIG4 gene, mutant type (Len-Mut) VSIG4 gene and empty vector virus (Len-Cont) and stimulated by the presence or absence of lipopolysaccharide (LPS), then divided into control group, LPS-Len-Mut group, LPS-Len-WT group, LPS-Len-Cont group, Len-Mut group, Len-WT group and Len-Cont group.The mRNA expression levels of the inflammatory factors interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were detected by real-time fluorescence quantitative PCR.Protein expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), glutathione peroxidase 4 (GPX4), nuclear transcription factor-κB (NF-κB) p65 subunit (P65), and phosphorylated P65 (PP65) were detected by Western blot.Cell phagocytic function was detected by phagocytosis assay.Cell migration ability was detected by cell scratch and transwell migration assay.LPS- stimulated HMC3 cells were co-cultured with 661W cells (mouse retinal photoreceptor cells), and the expression levels of B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X (Bax) proteins of the cells were detected by Western blot.The number of apoptotic cells was determined by apoptosis assay. Results:VSIG4 was localized to microglia in mouse retina.The real-time fluorescence quantitative PCR results showed that compared with LPS-Len-WT group, the relative expression levels of IL-1β and TNF-α mRNA in HMC3 cells were significantly increased in LPS-Len-Mut group (both at P<0.05).The Western blot results showed that compared with LPS- Len-WT group, the protein expression levels of Nrf2, HO-1, and GPX4 in HMC3 cells were significantly reduced in LPS-Len-Mut group, and the PP65/P65 ratio was significantly increased (all at P<0.05).The phagocytic experiment results showed that the phagocytic rates of HMC3 cells in Len-Cont group, LPS-Len-Cont group, LPS-Len-WT group, and LPS-Len-Mut group were (35.67±3.22)%, (63.67±10.07)%, (84.00±3.46)%, and (64.67±2.31)%, respectively, showing a statistically significant difference ( F=59.06, P<0.001).Compared with LPS-Len-WT group, the phagocytic rate of HMC3 cells was significantly reduced in LPS-Len-Mut group ( P<0.05).The results of cell scratch and transwell migration assay showed that compared with LPS-Len-WT group, the migration rate of HMC3 cells at 24 and 48 hours and the number of invading cells per unit area at 24 hours were significantly reduced in LPS-Len-Mut group (all at P<0.05).Compared with LPS-Len-WT group, the expression ratio of Bax/Bcl-2 protein and the number of cell apoptosis were significantly increased in the LPS-Len-Mut group under the co-culture system (both at P<0.05). Conclusions:VSIG4 is localized to mouse retinal microglia.When the VSIG4 gene in RP mutates, HMC3 cells under LPS stimulation exhibit a series of changes, including activation of the NF-κB signaling pathway, decreased activation of the Nrf2/HO-1 signaling pathway, increased secretion of inflammatory cytokines, reduced phagocytic and migratory abilities, and increased cell apoptosis in co-culture systems.
5.Effects of Polygonatum Kingianum Coll.et Hemsl on Oxidative Stress and Expression of Nrf2/HO-1 Signaling Pathyway in Diabetes Rats with Skin Lesions
Xiangduo ZUO ; Yajing XU ; Bin QIU ; Jingping LI ; Jie YU
World Science and Technology-Modernization of Traditional Chinese Medicine 2023;25(9):2959-2966
Objective To investigate the effects of Polygonatum kingianum on wound healing and nuclear factor-erythroid 2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)signaling pathway in diabetic skin injury rats.Methods Diabetic rat models were established and 48 rats were randomly divided into model group,sitagliptin group(10 mg·kg-1),Polygonatum kingianum water extract low dose group(2 g·kg-1),Polygonatum kingianum water extract high dose group(8 g·kg-1)and Polygonatum Kingianum alcohol extract low and high dose group(2 g·kg-1 and 8 g·kg-1).8 in each group;Another control group was set up.After 4 weeks of intragastric administration,all rats established back skin wounds,and continued to be administered for 14 days after operation.At the end of the experiment,the rats were killed,and blood glucose,glycosylated hemoglobin(GHb),plasma levels of H2O2,MDA,SOD,GSH and wound margin skin tissue T-AOC,SOD,MDA levels were measured.The relative expression of Nrf2 and HO-1 mRNA in wound margin skin tissue was measured by fluorescence quantitative method.Results Compared with the model group,the levels of SOD and GSH in plasma and the relative expressions of Nrf2 and HO-1 mRNA in wound margin skin tissue in the low and high dose groups of ethanol extract of Polygonatum kingianum,and the low and high dose groups of water extract of Polygonatum kingianum were increased(P<0.01,P<0.001).The levels of glycosylated hemoglobin(GHb)in plasma and MDA in wound margin tissue were decreased(P<0.05,P<0.01,P<0.001).The level of T-AOC in the high dose group was increased(P<0.01).The SOD level of skin tissue in the low dose group of Polygonatum kingianum water extract was increased(P<0.01),and the level of H2O2 in the low dose group was decreased(P<0.01).Conclusion Polygonatum canaliculatum can up-regulate Nrf2/HO-1 signaling pathway,regulate excessive oxidative stress,and promote wound healing.
6.Analysis of the feasibility and safety of repair of ureteral stricture with oral mucosal graft
Xingyuan XIAO ; Huixia ZHOU ; Yi WANG ; Xuepei ZHANG ; Kunlin YANG ; Gonghui LI ; Qiang FU ; Jingping GE ; Shengjun BAO ; Guangheng LUO ; Xiongjun YE ; Yixiang LIAO ; Yujie XU ; Yinan ZHANG ; Xuesong LI ; Bing LI
Chinese Journal of Urology 2023;44(2):121-127
Objective:To summarize and analyze the current application status of oral mucosal graft (OMG) technique in the repair of ureteral strictures in China, and clarify the feasibility, safety and effectiveness of this technique.Methods:The 175 patients who underwent repair of ureteral stricture using oral mucosal patches from June 2015 to February 2022 were etrospectively analyzed in 14 medical centers in China, including 49 cases in Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 32 cases in Affiliated Seventh Medical Center of PLA General Hospital, 3 cases in The Second Hospital of Anhui Medical University, 6 cases in The First Affiliated Hospital of Zhengzhou University, 56 cases in Peking University First Hospital, 3 cases in Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 cases in Shanghai Sixth People' s Hospital, 4 cases in General Hospital of Estern Theater Command, 4 cases in Lanzhou University Second Hospital, 2 cases in Guizhou Province People 's Hospital, 2 cases in Peking University People' s Hospital, 5 cases in Jinzhou First People's Hospital, 5 cases in The First Affiliated Hospital of Wannan Medical College, 1 case in Shandong Provincial Hospital. In this study, 127 patients (72.6%) used lingual mucosal patches, 32(18.3%) labial mucosa, and 16(9.1%) buccal mucosa. The surgical approach for OMG ureteral reconstruction was mainly minimally invasive, with robot-assisted laparoscopy in 84 patients (48.0%), traditional laparoscopic surgery in 87 patients (49.7%), and open surgery in only 4 patients (2.3%). There were 133 males and 42 females with an average age of (35.0±17.2) years. The mean body mass index (BMI) and stenosis length were (23.1±4.1) kg/m 2 and (4.7±1.8) cm, respectively. The stricture was located in the left ureter in 116 patients, right ureter in 58 case and bilateral ureter in 1 case. The most common causes of ureteral stricture were endoscopic surgery in 88(50.3%)patients, congenital stricture in 55(31.4%)patients, failed ureteroplasty in 29(16.6%)patients, history of extracorporeal shock wave lithotripsy in 13(7.4%)patients, radiotherapy history in 3(1.7%)patients and other causes in 6(3.4%)patients. Strictures were mainly located in the upper ureter, accounting for 61.7% (108/175 cases), followed by 36.0% (63/175) at the ureteropelvic junction and 2.3%(4/175)in the middle ureter. According to the surgical methods, the patients were divided into robot-assisted laparoscopic surgery group ( n=84), traditional laparoscopic surgery group ( n=87)and open surgery group ( n=4). Subgroup analysis of patients in robot-assisted laparoscopic and traditional laparoscopic surgery groups was performed. There were no significant difference in preoperative data between the two groups except for age (32.0±18.3) years vs.(37.0±15.9)years, P=0.040], BMI[(22.5±4.3)kg/m 2 vs. (23.7±3.6)kg/m 2, P=0.028], and etiology of stenosis [endoscopic injury, 34(40.5%) vs. 53(60.9%), P=0.012]. Preoperative hydronephrosis and stricture length were assessed by CTU and ureterography. Ureterography 7-9 weeks after surgery showed patency of the reconstructed segment, or no recurrence of hydronephrosis was judged as success. Evaluate the operation method, operation time, success rate, length of OMG in repairing ureteral stricture between laparoscopic and robot-assisted groups. Results:The overall success rate of oral mucosal graft repair surgery reached 97.7%(171/175). The success rate of ureteral reconstruction in the two groups were 96.4%(81/84)and 98.9%(86/87), respectively ( P=0.351), and the difference was not statistically significant. There was no significant difference for operation time, intraoperative blood loss, and mean oral mucosal length between the robotic and laparoscopic groups[(244.7±85.8) min and (222.7±83.5)min ( P=0.116), (58.9±38.6) ml and (68.4±45.5) ml ( P=0.217), (5.0±2.0) cm and (4.6±1.5) cm ( P=0.350)], respectively.Postoperative complications were reported in 23 (13.1%) patients, such as fever, urinary leakage, lymphatic leakage, infection, but only 2 (1.4%) cases patients had complications of Clavien-Dindo score ≥ Ⅲ. The two patients developed urinary stricture after surgery with failed conservative treatment, and no urinary stricture occurred following endoscopic treatment.The short-term (three months after surgery)incidence of complications in the site where the oral mucosa was taken, such as difficulty in opening mouth, pain, and swelling, was 12.0% (21/175), and there was no significant difference for oral complications between patients harvesting different length of mucosal graft. Conclusions:Ureteroplasty with oral mucosal graft is a safe, feasible and reliable technique for ureteral reconstruction. At present, minimally invasive technology is the main surgical approach for ureteroplasty, and there is no significant difference in operation time and success rate between robotic surgery and laparoscopic surgery.
7.Application of PBL teaching guided by anesthesia plan in the teaching of anesthesia undergraduate interns
Wa QU ; Chuangxin LI ; Tianyu SUN ; Jingping YAO ; Yu HUAN ; Jianjun XU
Chinese Journal of Medical Education Research 2022;21(9):1198-1202
Objective:To explore the application effect of PBL teaching guided by anesthesia plan in clinical teaching of anesthesia undergraduate practice.Methods:A total of 34 anesthesiology undergraduates who practiced in Daqing Oilfield General Hospital/The Tenth Affiliated Hospital of Qiqihar Medical University from January 2020 to September 2020 were selected and randomly divided into experimental group ( n=17) and control group ( n=17). The experimental group adopted PBL teaching guided by anesthesia plan, while the control group adopted traditional teaching. The theoretical assessment results, case analysis assessment results, and clinical skills assessment results of the two groups of undergraduate interns were compared and analyzed. Additionally, a questionnaire survey was conducted to evaluate the students' comprehensive ability. SPSS 22.0 was used for t test. Results:The scores and total scores of theoretical knowledge and anesthesia skills in the experimental group were higher than those in the control group, and the difference was statistically significant ( P<0.05). Before learning, there was no significant difference in scores and total scores of comprehensive ability between the two groups ( P>0.05); after learning, the comprehensive ability of the two groups of students were improved, and those of the experimental group were higher than those of the control group ( P<0.05). Conclusion:PBL teaching guided by anesthesia plan can effectively improve the mastery of theoretical knowledge, clinical operation skills and case analysis ability of anesthesia undergraduate interns, and the teaching effect is good, which is worthy of further promotion.
8.Development of Plantar Force Assessment Model for Patients with Patellofemoral Pain
Wenqi ZHOU ; Zheng YUAN ; Jing RAN ; Jie XU ; Qiaomei HONG ; Xiaobing LUO ; Hai SHEN ; Jingping WANG
Journal of Medical Biomechanics 2022;37(4):E748-E753
Objective To develop plantar force model of patellofemoral pain (PFP), so as to provide theoretical references for the assessment of PFP rehabilitation. Methods The case-control study was conducted, and a total of 126 patients with PFP and 126 healthy controls matched by gender and age were enrolled in the study. The participants were tested for plantar force and pressure during level walking, and twelve plantar regions were divided and recorded. Whether the participants suffered PFP was analyzed as dependent variable, meanwhile the peak force and peak pressure in 12 plantar regions of participants at selected speed during level walking were analyzed as independent variables. Conditional logistic regression (CLR) equations of peak force and peak pressure with PFP were established, respectively. The receiver-operating characteristic (ROC) curve of the corresponding equations was derived, and the area under ROC curve was calculated to analyzed the validity of different equations on PFP assessment. Results The CLC equation of peak force in 12 plantar regions of the participants with FFP was constructed, and only peak force of lateral heel was in the equation. The CLC equation of peak pressure in each plantar region included medial heel, midfoot, 1st and 2nd metatarsals. Meanwhile, the area under ROC curve of the pressure equation was larger than that of the force equation. Conclusions Peak force and pressure at different plantar regions can be used to assess PFP during level walking, and peak pressure is more effective for assessment.
9.Surgical technique and efficacy of P. R.E.S.S. bladder cuff excision
Zhenjie WU ; Lin YAO ; Liang WANG ; Jitao WU ; Le QU ; Yifan XU ; Tianyu WU ; Zhao HUANGFU ; Gang WU ; Wenquan ZHOU ; Jingping GE ; Hongwei ZHAO ; Zhiyu LIU ; Liqun ZHOU ; Linhui WANG
Chinese Journal of Urology 2021;42(8):602-608
Objective:To explore the surgical technique and efficacy of pure retroperitoneoscopic extravesical standardized seeable (P.R.E.S.S.) technique for bladder cuff excision (BCE).Methods:Ninety five patients with UTUC from five domestic centers (30 cases from Changzheng Hospital, 21 cases from Peking University First Hospital, 20 cases from Yuhuangding Hospital, 21 cases from Dalian Medical University affiliated No.2 Hospital and 3 cases from General Hospital of Eastern Theater Command)between August 2017 and December 2020 were retrospectively analyzed. There were 57 males and 38 females with a mean age of (67.7±10.0) years and median tumor size of 3.0 cm. All patients underwent pure retroperitoneoscopic radical nephroureterectomy with a single surgical position and four (36 cases) or five (59 cases) trocar layout according to the surgeon’s prefer habit and experience. The demographics of the two groups were the age of [(66.3±11.2)years vs. (68.6±9.1)years], male/female ratio of (25/11 cases vs. 32/27 cases), body mass index of [(25.0± 3.0)kg/m 2 vs. (24.8±3.4)kg/m 2], tumor maximum diameter of [2.8(1.6, 3.5)cm vs. 3.0(2.0, 4.0)cm], left/right side tumor of(19/17 cases vs. 34/25 cases), T 1-2/T 3-4/Tis stage of(25/10/4 cases vs. 49/10/0 cases), and multifocal tumors of(3 cases vs. 2 cases), and the difference was not statistically significant( P>0.05). On the other hand, the differences of hydronephrosis of the operated kidney(13 cases vs. 39 cases, P=0.004), and tumor location (in renal pelvis or calyx or upper/middle/lower ureter being 23/9/4 cases vs. 35/4/20 cases, P=0.005), were statistically significant. The umbilical artery cord was used as anatomical landmark in the process of P. R.E.S.S. bladder cuff excision. The pelvic floor and extraperitoneal space around the ureter were expanded, the bladder wall was opened to form pneumovesicum, and a sufficient bladder cuff resection and exact bladder cuff closure was performed. Perioperative outcomes and follow-up data were analyzed, and the clinical outcomes between the four and five trocars were compared to evaluate the impact of trocar layout on the surgical outcomes. Results:There were 91(95.8%) cases successfully undergoing P. R.E.S.S. BCE technique, with one case converted to open BCE due to bleeding and three cases converted to distal ureter Hem-o-lok clipping because of poor exposure. Median operative time was 180(125, 230)min, and estimated blood loss was 100(50, 100)ml. The overall complication rate was 10.5%(10/95), including 2 cases(2.1%) of intraoperative bleeding, with 1 case treated by transfusion (400 ml), the other case converted to open surgery without transfusion. There were 8 cases of postoperative complications(8.4%), including 7 cases of Clavien-Dindo grade Ⅱ(3 cases of secondary hemorrhage, one case for each of drug allergy, acute renal insufficiency, blood creatinine increased to 490 μmol/L, or lung infection with lymphatic leakage), 1 case of grade Ⅲa(intestinal obstruction treated with insertion of the intestinal obstruction catheter under local anesthesia), and all these patients were discharged smoothly. The difference between the four and five trocars was not statistically significant in the following variables, including the rate of surgical conversion(8.3% vs. 1.7%), estimated intraoperative blood loss(100 ml vs. 60 ml), ratio of intraoperative lymph node dissection (25.0% vs.20.3%), P. R.E.S.S. bladder cuff excision success rate(91.7% vs.98.3%), the incidence of intraoperative and postoperative complications (13.8% vs.8.5%), pT 1-2/pT 3-4/pTis stage(22/11/3 cases vs.37/19/3 cases) and the proportion of recurrence or metastasis(8.3% vs.3.4%)(all P>0.05). However, the differences in the operation time(190 min vs.170 min, P=0.011)and postoperative hospital stay(5 d vs.6 d, P=0.005) were statistically significant. Conclusions:P. R.E.S.S. bladder cuff resection technique is safe and feasible during the procedure of pure retroperitoneoscopic radical nephroureterectomy by a single surgical position and facilitates seeable adequate bladder cuff excision by establishing an enlarged pelvic lateral extraperitoneal space and pneumovesicum. Five-trocar technique is more suitable for patients with lower ureteral tumors but may be associated with a longer postoperative hospital stay compared with the four-trocar technique.
10.Effect of different support angles on the fitness of removable partial denture framework fabricated using selective laser melting technique
Da NI ; Yan DONG ; Jingping PENG ; Yi XU ; Mengxin YANG ; Yijun DAI
Chinese Journal of Stomatology 2020;55(3):165-170
Objective:To evaluate the fitness of bilateral free-end dentition defect removable partial denture framework fabricated by selective laser melting (SLM) technique with different support angles.Methods:After the control group has been set to eliminate the system error, and according to the standard model of bilateral mandibular posterior teeth loss, eighteen titanium alloy removable partial denture frameworks fabricated by SLM technology were divided into 3 groups with support angles of 0° (horizontal group), 45°(45° group) and 90° (vertical group). Plaster cast with duplicated structure of tissue surface of the removable partial denture (RPD) framework was obtained. A three-dimensional scanner was used to scan original and duplicated plaster casts. The gaps between framework and the model in different parts were analyzed using Geomagic Qualify software to evaluate the fitness of the framework with visual method.Results:The framework fits on the plaster model completely, and its tissue surface fitted on the plaster model well. The deviation between frameworks and plaster casts was calculated as follow: the total deviations of the horizontal, 45°, and vertical group were (0.146±0.017), (0.182±0.015) and (0.185±0.022) mm respectively. The mean deviation of the horizontal group was significantly less than those of the 45° group and the vertical group ( P<0.05). Moreover, there was no significant difference in the total deviation between the 45° group and the vertical group. The total deviation of occlusal rest of the horizontal group was significantly less than that of the 45° group ( P<0.05). However, no significant difference was detected in the deviation of occlusal rest among the vertical group, the horizontal group, and the 45° group ( P>0.05). There was no significant difference in the deviation of occlusal rest among the vertical group, the horizontal group, and the 45° group. The deviation of clasp of the horizontal group was significantly smaller than those of the 45° group and the vertical group ( P<0.05). Whereas, there was no significant difference in the deviation of clasp between the 45° group and the 90° group ( P>0.05). No significant difference was found in the deviation of lingual bar among the three groups ( P>0.05). Conclusions:Among the three kinds of bilateral free-end dentition defect RPD framework fabricated by SLM in different support angles, horizontal printing was proved to reach the minimal deviation, even though the fitness of all three kinds of frameworks can fullfil clinical requirements according to previous studies.

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