Experts consensus on the procedure of dental operative microscope in endodontics and operative dentistry

The dental operative microscope has been widely employed in the field of dentistry,particularly in endodontics and operative dentistry,resulting in significant advancements in the effectiveness of root canal therapy,endodontic surgery,and dental restoration.However,the improper use of this microscope continues to be common in clinical settings,primarily due to operators’insufficient understanding and proficiency in both the features and established operating procedures of this equipment.In October 2019,Professor Jingping Liang,Vice Chairman of the Society of Cariology and Endodontology,Chinese Stomatological Association,organized a consensus meeting with Chinese experts in endodontics and operative dentistry.The objective of this meeting was to establish a standard operation procedure for the dental operative microscope.Subsequently,a consensus was reached and officially issued.Over the span of about four years,the content of this consensus has been further developed and improved through practical experience.

Effect of gamification applications on success of dentistry students

BACKGROUND Gamification,the use of game materials in education,has been used in several scientific fields,and studies have demonstrated its effectiveness in student comprehension.AIM To evaluate whether the success of 4th-and 5th-grade dentistry students increases when using the gamification applications Kahoot!and Mentimeter.METHODS An experimental design was used to measure the effect of gamification applications on students who were taught using the traditional method.For this purpose,Mentimeter and Kahoot!applications were used in this experimental study.Three groups of 4th-and 5th-grade students were formed:Mentimeter,Kahoot!,and control groups.The effect of gamification applications on achievement was evaluated by administering a post-test to these groups after the instructional process.One-way analysis of variance and t-tests were used for statistical analyses.RESULTS A total of 35.5%of the students were in the Mentimeter group,29.8%in the Kahoot!group,and 34.6%in the control group.Of the total number of students,54.8%were female and 45.2%were male,while 52.2%were 5th-grade students and 47.8%were 4th-grade students.The overall grade point average was found to be 66.65(range,24-100).There was a statistically significant difference in average success scores between students of different groups(P=0.003<0.05)and grades(P=0.036<0.05).The average success score was the highest in the Mentimeter group(71.64)and the lowest in the Kahoot!group(62.15).In the control group,this score was 65.41.The average success score was higher for students in the 5thgrade(68.16)and for female students(68.84).CONCLUSION Gamification has a great potential in the education of dentomaxillofacial radiology students.Mentimeter outperformed both the Kahoot!and the traditional method in terms of average student success rates.

Micro-Computed Tomography Applications in Dentistry

Micro-computed tomography (MCT) encompasses two primary scanning options: ex-vivo and in-vivo imaging. Ex-vivo scanning involves the examination of extracted teeth or dental specimens, allowing for detailed analyses of the microarchitecture of mineralized tissue. By analyzing the microarchitecture of dental tissues, MCT can provide valuable information about bone density, porosity, and microstructural changes, contributing to a better understanding of disease progression and treatment outcomes. Moreover, MCT facilitates the quantification of dental parameters, such as bone volume, trabecular thickness, and connectivity density, which are crucial for evaluating the efficacy of dental interventions. This present study aims to comprehensively review and explore the applications of MCT in dentistry and highlight its potential in advancing research and clinical practice. The results depicted that the quantitative approach of MCT enhances the precision and reliability of dental research. Researchers and clinicians can make evidence-based decisions regarding treatment strategies and patient management, relying on quantifiable data provided by MCT. The applications of MCT in dentistry extend beyond research, with potential clinical implications in fields such as dental implantology and endodontics. MCT is expected to play an increasingly significant role in enhancing our understanding of dental pathologies, improving treatment outcomes, and ultimately, benefiting patient care in the field of dentistry.

Association between operative position and postoperative nausea and vomiting in patients undergoing laparoscopic sleeve gastrectomy

BACKGROUND Bariatric surgery is one of the most effective ways to treat morbid obesity,and postoperative nausea and vomiting(PONV)is one of the common complications after bariatric surgery.At present,the mechanism of the high incidence of PONV after weight-loss surgery has not been clearly explained,and this study aims to investigate the effect of surgical position on PONV in patients undergoing bariatric surgery.AIM To explore the effect of the operative position during bariatric surgery on PONV.METHODS Data from obese patients,who underwent laparoscopic sleeve gastrectomy(LSG)in the authors’hospital between June 2020 and February 2022 were divided into 2 groups and retrospectively analyzed.Multivariable logistic regression analysis and the t-test were used to study the influence of operative position on PONV.RESULTS There were 15 cases of PONV in the supine split-leg group(incidence rate,50%)and 11 in the supine group(incidence rate,36.7%)(P=0.297).The mean operative duration in the supine split-leg group was 168.23±46.24 minutes and 140.60±32.256 minutes in the supine group(P<0.05).Multivariate analysis revealed that operative position was not an independent risk factor for PONV(odds ratio=1.192,95%confidence interval:0.376-3.778,P=0.766).CONCLUSION Operative position during LSG may affect PONV;however,the difference in the incidence of PONV was not statistically significant.Operative position should be carefully considered for obese patients before surgery.

Defining the association between the prolonged operative time and 90-day complications in patients undergoing radical cystectomy

Objective:Radical cystectomy is a complex lengthy procedure associated with postoperative morbidity.We aimed to assess the operative time(OT)in patients undergoing radical cystectomy and its impact on 90-day postoperative complications and readmission rates.Methods:The retrospective cohort study included 296 patients undergoing radical cystectomy and urinary diversion from May 2010 to December 2018 in our institution.The OT of 369 min was set as a cutoff value between short and long OT groups.The primary outcome was 90-day postoperative complication rates.Secondary outcomes were gastrointestinal recovery time,length of hospital stay,and 90-day readmission rates.Results:The overall incidence of 90-day postoperative complications was 79.7%where 43.2%representing low-grade complications according to the ClavieneDindo classification(Grade 1 and Grade 2),and 36.5%representing high-grade complications(Grade3).Gastrointestinal tract and infectious complications are the most common complications in our data set(45.9%and 45.6%,respectively).On multivariable analysis,prolonged OT was significantly associated with odds of high-grade complications(odds ratio 2.340,95%confidence interval 1.288e4.250,p=0.005).After propensity score-matched analysis,a higher incidence of major complications was identified in the long OT group 55(51.4%)compared to 35(32.7%)in the short OT group(p=0.006).A shorter gastrointestinal tract recovery time was noticed in the short OT group(p=0.009).Prolonged OT was associated with a higher 90-day readmission rate on univariate and multivariate analyses(p<0.001,p=0.001,respectively).

Clinical effect of operative vs nonoperative treatment on humeral shaft fractures:Systematic review and meta-analysis of clinical trials

BACKGROUND Whether operation is superior to non-operation for humeral shaft fracture remains debatable.We hypothesized that operation could decrease the nonunion and reintervention rates and increase the functional outcomes.AIM To compare the clinical efficacy between operative and nonoperative approaches for humeral shaft fractures.METHODS We searched the PubMed,Web of Science,ScienceDirect,and Cochrane databases from 1990 to December 2023 for clinical trials and cohort studies comparing the effects of operative and conservative methods on humeral shaft fractures.Two investigators independently extracted data from the eligible studies,and the other two assessed the methodological quality of each study.The quality of the included studies was assessed using the Cochrane risk bias or Newcastle-Ottawa Scale.The nonunion,reintervention and the overall complications and functional scores were pooled and analyzed using Review Manager software(version 5.3).RESULTS A total of four randomized control trials and 13 cohort studies were included,with 1285 and 1346 patients in the operative and nonoperative groups,respectively.Patients in the operative group were treated with a plate or nail,whereas those in the conservative group were managed with splint or functional bracing.Four studies were assessed as having a high risk of bias,and the other 13 were of a low risk of bias according to the Newcastle-Ottawa Scale or Cochrane risk bias tool.The operative group had a significantly decreased rate of nonunion[odds ratio(OR)0.30;95%CI:0.23 to 0.40,reintervention(OR:0.33;95%CI:0.24 to 0.47),and overall complications(OR:0.62;95%CI:0.49 to 0.78)].The pooled effect of the Disabilities of Arm,Shoulder,and Hand score showed a significant difference at 3[mean difference(MD)-8.26;95%CI:-13.60 to-2.92],6(MD:-6.72;95%CI:-11.34 to-2.10),and 12 months(MD:-2.55;95%CI:-4.36 to-0.74).The pooled effect of Visual Analog Scale scores and the Constant-Murley score did not significantly differ between the two groups.CONCLUSION This systematic review and meta-analysis revealed a trend of rapid functional recovery and decreased rates of nonunion and reintervention after operation for humeral shaft fracture compared to conservative treatment.

Aqueous Supercapacitors With Wide Operative Voltage Window and Long Cycling Life Enabled by Electrolyte Hybridization Effect

Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the development of aqueous electrolytes to a new height,the WIS electrolytes with an operative voltage window of up to 2.5 V is still very scarce.Herein,in order to enrich the type of aqueous electrolyte with high operative voltage,tetramethylammonium trifluoromethanesulfonate(TMAOTf)based WIS electrolyte was used as a model to construct WIS based hybrid electrolyte with acetonitrile(ACN)co-solvent and LiTFSI co-solute.In view of the coordination effect of ACN and Lit on free water in TMAOTf based WIS electrolyte,the TMAt-Lit-AWIS electrolyte has the electrochemical stabilization window of up to 3.35 V.Further coupled with the commercial YP-50F electrodes,TMAt-Lit-AWIS based SCs exhibited wide operative voltage window(2.5 V),long cycling life(45,000 cycles)and good low-temperature performance(99.99%capacitance retention after 2000 cycles at20℃).The design of this hybrid electrolyte will enrich the types of aqueous hybrid electrolytes with long cycling life and wide operative voltage window.

Advances in nonpharmacologic interventions for operative puncture pain in children

Venipuncture is an indispensable nursing procedure for intravenous infusion,but it is also an invasive procedure that is highly resisted by hospitalised children due to pain or fear.Non-pharmacological interventions are widely used in clinical practice due to their low cost,low risk and simplicity.This article provides a review with the aim of providing a reference for the selection of optimal analgesic interventions in the future.

General Considerations for the Practice of Pediatric Dentistry in the Period of COVID-19 Pandemic: A Review

Context: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2) has been identified in December 2019. Since then, it has been spreading around the world and has caused a pandemic. Strict safety protocols should be followed to resume dental treatments. Evidence Acquisition: A comprehensive search was conducted on PubMed, Scopus, Medline and google scholar databases using the MeSH words of COVID-19, SARS-COV-2, Dentistry, and Child from December 2019 until July 2020. Results: Among COVID-19 patients, asymptomatic patients still are considered to be serious carriers of the COVID-19 which can play a key role in transmission of the virus. Children are reported to be less than 2 percent of the infected population and are considered as serious potential carriers. Telemedicine can take a key part in educating parents regarding this matter. Chronic and rare diseases such as Kawasaki Disease (KD) might show acute and more frequent symptoms amongst COVID-19 patients. Salivary testing can be a convenient chairside way for COVID-19 and it has been shown to be effective in identifying critically ill patients. Dry mouth and amblygeustia have been reported to be the oral symptoms of the COVID-19. Conclusions: Dentists must make tough decisions in prioritizing patient’s needs in the period of pandemic. They should frequently get updated as the situation is fluid and the protocols might change.

History of Dentistry from the Period of the Ottoman Empire to the Republican Period

The Ottoman-Turkish medicine and dentistry was born and developed in the lands of Anatolia. The most mature period of the Islamic medicine was in the Ottoman Empire on the lands of Anatolia. While inheriting the Turkish-Islamic science and culture structure and the ancient age and Old Greek science, it was integrated with the medicine philosophy here. In the 13th and 15th centuries, in Ottomans, the development of the dentistry was on the issues of the dental diseases and periodontology. In the 14th and 15th centuries, it was observed in the medicine books of the Turkish physician writers that they were also dealing with the child dentistry as issues. That the dental medicine took place in the works of art written between the 15th and 19th century shows the existence of the surgeons realizing the tooth extraction. With the opening of the first dentist school in the year of 1909, the training of dentistry started. In this study, the issue of the development and training of the dentistry in the Ottomans among the 13th-19th centuries were dealt with the outlines. Also, the first examples and fundamental works of art of the dentistry literature from the Ottoman Empire to the Republican period will be told shortly.

Use and Attitudes towards Teleconsultation in Dentistry

An electronic (web-based) questionnaire was devised to find out the extent of teleconsultation and e-mail use for patient-provided communications in dentistry. This project was carried out in 2011 inthe health care district of South-Ostrobothnia, in South-Western Finland.The questionnaire was sent by e-mail to all 120 regional dentists, to which 76 replies were obtained (response rate 63%). The responses indicated a surprisingly positive attitude towards teleconsultation. A clear majority of 91% indicated that it could bring additional benefits to the current consultation methods.This study revealed that a slight majority of dentists in the region use e-mail for patient communication and 53% used e-mail for consultation. Approximately 10% use videoconferencing for consultation.The study also revealed that the majority of those who do not yet use electronic consultation are willing to try them out in the future. Security issues are a concern for many dentists. Practically all respondents wish for written instructions on the use of electronic consultation.

Gingival-derived mesenchymal stem cells:An endless resource for regenerative dentistry

The gingiva, the masticatory portion of the oral mucosa, is excised and discarded frequently during routine dental treatments and following tooth extraction, dental crown lengthening, gingivectomy and periodontal surgeries. Subsequent to excision, healing eventually happens in a short time period after gingival surgery. Clinically, the gingival tissue can be collected very easily and, in the laboratory, it is also very easy to isolate gingival-derived mesenchymal stem cells (GMSCs) from this discarded gingival tissue. GMSCs, a stem cell population within the lamina propria of the gingival tissue, can be isolated from attached and free gingiva, inflamed gingival tissu-es, and from hyperplastic gingiva. Comparatively, they constitute more attractive alternatives to other dental-derived mesenchymal stem cells due to the availability and accessibility of gingival tissues. They have unique immunomodulatory functions and well-documented self-renewal and multipotent differentiation properties. They display positive signals for Stro-1, Oct-4 and SSEA-4 pluripotency-associated markers, with some co-expre-ssing Oct4/Stro-1 or Oct-4/SSEA-4. They should be considered as the best stem cell source for cell-based therapies and regenerative dentistry. The clinical use of GMSCs for regenerative dentistry represents an attrac-tive therapeutic modality. However, numerous biological and technical challenges need to be addressed prior to considering transplantation approaches of GMSCs as clinically realistic therapies for humans.

Pathways of fear and anxiety in dentistry: A review

The aim of this article was to analyze the theories underpinning dental fear, anxiety and phobias. To be included, articles must have been published between the years of 1949 and 2013 concerning fears and phobias within dentistry and/or psychiatry. Of 200 articles originally under review, 140 were included and reviewed by the authors.Five specific pathways relating to dental fear and anxiety were identified; Cognitive Conditioning, Informative, Visual Vicarious, Verbal Threat, and Parental. Eight currently accepted management techniques across all dental disciplines for dental fear and anxiety were identified. Further research is required to identify clinical diagnosis and treatment for fears originating from different pathways.

Platelet preparations in dentistry:How? Why? Where? When?

The aim of this article is to review the outcomes of platelet preparations in dentistry. A structured electronic search discovered 348 articles, which described the use of autologous platelet concentrates with a relevance to clinical dentistry. Among these articles, 220 articles investigated platelet rich plasma, 99 investigated platelet rich fibrin, 22 investigated plasma rich in growth factors and 7 investigated the use of concentrated growth factors. Several studies reported beneficial treament outcomes in terms of enhanced bone and soft tissue regeneration.

Preoperative diagnosis and operative effect of intracranial aneurysm with three-dimensional computed tomography angiography

BACKGROUND ： Digital subtraction angiography （DSA） is always regarded as the golden standard for diagnosis of intracranial aneurysm; however, the procedure is complex, traumatic, expensive and easy to induce vascular complication. Three-dimensional computed tomography angiography （3D-CTA） can make up deficiencies of DSA; therefore, it is used in clinical therapy wider and wider. OBJECTIVE ： To evaluate the clinical effect of 3D-CTA on disruption and hemorrhage of intracranial aneurysm pre- and post-operation and compare with the effect of DSA. DESIGN ： Auto-control contrast observation SETTING ： Department of Neurosurgery, Shengjing Hospital of China Medical University PARTICIPANTS ： A number of 106 patients with disruption and hemorrhage of intracranial aneurysm were selected from the Department of Neurosurgery, Shengjing Hospital of China Medical University from January 2003 to April 2006. All patients were diagnosed with cranial operation and consent. There were 47 males and 59 females aged from 3-76 years with the mean age of （47±13） years. Among them, 82 patients had extensive subarachnoid hemorrhage （SAH）, 7 had hemorrhage at longitudinal fissure, and 17 had hemorrhage at ambiens cistema and lateral fissure. Moreover, intraventricular hematocele was accompanied on 13 patients and hematom on 9 patients. METHODS： （1） 3D-CTA examination： Siemens SOMATOM Sensation 64 CT was used in this study. The thickness was 1 mm and interval of reconstruction was 0.8 mm. Localizing section was plainly scanned as the standard of canthus line. Scan ranged from 30 mm below sella to 50 mm above sella. Non-ion contrast medium of Omnipaque 350 （concentration of iodine was 350 g/L） was inserted into anterior vein of elbow with 18G trochar retained with high-pressured injectoc pum. The speed was 4.5 mL/s and the total volume was 80-100 mL with the means of 90 mL. Scan started at 10-20 s after injection of contrast medium. Original image was dealt with Leonardo workstation and retreated with Syngo software. Volume rendering and maximum intensity projection were used to reconstructed images, （2） All 106 patients suffered from occlusion of aneurysm clamp. Before operation, 3D-CTA was undertaken and DSA was followed. After operation, patients were rechecked with 3D-CTA. MAIN OUTCOME MEASURES： Comparisons between 3D-CTA and DSA. RESULTS ： All 106 patients were involved in the final analysis. （1） Examination of 3D-CTA and DSA： Among 118 patients with aneurysm, 110 were checked with 3D-CTA and the detected rate was 93.2% （110/118）. Among other 8 cases, 3 were negative and checked again with DSA; 1 had pericallosal aneurysm, 1 ophthalmic aneurysm, and 1 anterior choroidal artery of aneurysm. 3D-CTA results of other 5 cases were suspicious, and then, they were regarded as having aneurysm with DSA. Before operation, correlation among site, body, neck of aneurysm and peripheral anatomic structure were shown sufficiently. After operation, 82 patients were rechecked with 3D-CTA, which was complete occlusion, precise, unobvious constriction, emphraxis or remains as compared with 3D-CTA those pre-operation. （2） Characteristics of 3D-CTA： With multiple vessels and angles, 3D-CTA observed the relationship between aneurysm neck and carried artery and showed thrombosis in cavity of aneurysm, calcification of aneurysm wall and peripheral structure of vessel at the same time. However, DSA could not detect the reactions mentioned above. It could delete image of cranium, simulate image of operative route, eliminate artifact induced by metal, but not distinguish blood stream direction. Meanwhile, posterior communicating artery was always poor during circle of Willis artery showing. CONCLUSION： （1） 3D-CTA is characterized by simple operation and non-invasive showing vascular stereo structure and correlation. Therefore, it is significant for diagnosis and designing plan of operative approach and focal location pre-operation and evaluating effect post-operation. （2） 3D-CTA does not completely replace DSA on the diagnosis of intracranial aneurysm.

Use of dentomaxillofacial cone beam computed tomography in dentistry

Cone-beam computed tomography(CBCT) was developed and introduced specifically for dento-maxillofacial imaging. CBCT possesses a number of advantages over medical CT in clinical practice, such as lower effective radiation doses, lower costs, fewer space requirements,easier image acquisition, and interactive display modes such as mutiplanar reconstruction that are applicable to maxillofacial imaging. However, the disadvantages of CBCT include higher doses than two-dimensional imaging; the inability to accurately represent the internal structure of soft tissues and soft-tissue lesions; a limited correlation with Hounsfield Units for standardized quantification of bone density; and the presence of various types of image artifacts, mainly those produced by metal restorations. CBCT is now commonly used for a variety of purposes in oral implantology, dentomaxillofacial surgery, image-guided surgical procedures, endodontics, periodontics and orthodontics. CBCT applications provide obvious benefits in the assessment of dentomaxillofacial region, however; it should be used only in correct indications considering the necessity and the potential hazards of the examination.

Modified physiological and operative score for the enumeration of mortality and morbidity risk assessment model in general surgery

AIM: To establish a scoring system for predicting the incidence of postoperative complications and mortality in general surgery based on the physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM), and to evaluate its efficacy. METHODS: Eighty-four patients with postoperative complications or death and 172 patients without postoperative complications, who underwent surgery in our department during the previous 2 years, were retrospectively analyzed by logistic regression. Fifteen indexes were investigated including age, cardiovascular function, respiratory function, blood test results, endocrine function, central nervous system function, hepatic function, renal function, nutritional status, extent of operative trauma, and course of anesthesia. Modified POSSUM (M-POSSUM) was developed using significant risk factors with its efficacy evaluated. RESULTS: The significant risk factors were found to be age, cardiovascular function, respiratory function, hepatic function, renal function, blood test results, endocrine function, nutritional status, duration of operation, intraoperative blood loss, and course of anesthesia. These factors were all included in the scoring system. There were significant differences in the scores between the patients with and without postoperative complications, between the patients died and survived with complications, and between the patients died and survived without complications. The receiver operating characteristic curves showed that the M-POSSUM could accurately predict postoperative complications and mortality.CONCLUSION: M-POSSUM correlates well with postoperative complications and mortality, and is more accurate than POSSUM.

Dentistry-ProConsult软件辅助石膏牙造模在口腔教学中的应用

背景:在口腔医学教学实践中,牙列的正常形态及咬合关系一直是教学的难点,但牙齿的咬合界面及功能耦联关系复杂,不易掌握,一直以来也是临床教学的难点和重点。目的:探索Dentistry-ProConsult 软件辅助石膏牙造模在口腔教学中的应用效果。方法:将44 名空军军医大学五年制口腔医学专业本科四年级学员随机分为2 组,对照组(n=21)在传统教学模式下学习不同类型牙齿的解剖结构和咬合关系及雕刻蜡牙,无任何功能软件的应用;试验组(n=23)在Dentistry-ProConsult 软件辅助石膏牙造模口腔教学模式下学习不同类型牙齿的解剖结构和咬合关系,通过Dentistry-ProConsult 软件辅助石膏牙造模口腔教学,带教教师可主动引导学生通过三维模型从不同层次和角度理解牙齿的正常形态及复杂的咬合关系,在此基础上结合3D 打印模型,让学员在石膏模具中逐一雕刻正常牙齿形态。学期末对学员的笔试成绩及操作成绩进行统计学分析。结果与结论:①试验组理论成绩高于对照组[(85.6±12.4),(79.3±15.7)分,t=6.735,P < 0.05],操作考试成绩高于对照组[(88.2±10.6),(82.5±14.5)分,t=7.182,P < 0.05];②问卷调查显示,试验组学员对于该课程的教学满意程度评分优于对照组[(87.5±8.7),(79.7±10.1)分,t=8.531,P < 0.05];③结果表明,Dentistry-ProConsult 软件辅助石膏牙造模教学方法显著提高了学员的理论及实践成绩,同时提高了学员的课堂满意度。

Choice of operative method for pancreaticojejunostomy and a multivariable study of pancreatic leakage in pancreaticoduodenectomy

BACKGROUND As one of the major abdominal operations,pancreaticoduodenectomy(PD)involves many organs.The operation is complex,and the scope of the operation is large,which can cause significant trauma in patients.The operation has a high rate of complications.Pancreatic leakage is the main complication after PD.When pancreatic leakage occurs after PD,it can often lead to abdominal bleeding and infection,threatening the lives of patients.One study found that pancreatic leakage was affected by many factors including the choice of pancreaticojejunostomy method which can be well controlled.AIM To investigate the choice of operative methods for pancreaticojejunostomy and to conduct a multivariate study of pancreatic leakage in PD.METHODS A total of 420 patients undergoing PD in our hospital from January 2014 to March 2019 were enrolled and divided into group A(n=198)and group B(n=222)according to the pancreatointestinal anastomosis method adopted during the operation.Duct-to-mucosa pancreatojejunostomy was performed in group A and bundled pancreaticojejunostomy was performed in group B.The operation time,intraoperative blood loss,and pancreatic leakage of the two groups were assessed.The occurrence of pancreatic leakage after the operation in different patients was analyzed.RESULTS The differences in operative time and intraoperative bleeding between groups A and B were not significant(P>0.05).In group A,the time of pancreatojejunostomy was 26.03±4.40 min and pancreatic duct diameter was 3.90±1.10 mm.These measurements were significantly higher than those in group B(P<0.05).The differences in the occurrence of pancreatic leakage,abdominal infection,abdominal hemorrhage and gastric retention between group A and group B were not significant(P>0.05).The rates of pancreatic leakage in patients with preoperative albumin<30 g/L,preoperative jaundice time≥8 wk,and pancreatic duct diameter<3 mm,were 23.33%,33.96%,and 19.01%,respectively.These were significantly higher than those in patients with preoperative albumin≥30 g/L,preoperative jaundice time<8 wk,and pancreatic duct diameter≥3 cm(P<0.05).Logistic regression analysis showed that preoperative albumin<30 g/L,preoperative jaundice time≥8 wk,and pancreatic duct diameter<3 mm were risk factors for pancreatic leakage after PD(odds ratio=2.038,2.416 and 2.670,P<0.05).CONCLUSION The pancreatointestinal anastomosis method during PD has no significant effect on the occurrence of pancreatic leakage.The main risk factors for pancreatic leakage include preoperative albumin,preoperative jaundice time,and pancreatic duct diameter.

A Palladium Based Alloy for Prosthetic Dentistry: Structure and Properties

Using the results of physical and chemical researches and mechanical tests of the Pd-Au-Cu-Sn system alloys, a new palladium-based alloy has been chosen and studied in detail. It has a higher plasticity and a lower hardness than the Palladent alloy, widely used in prosthetic dentistry: its hardness is lower than 300 MPa, and its specific elongation is 10%~14 %. At the same time, such important practical characteristics of the alloys as the strength of adhesion to ceramics and thermal expansion coefficient are almost similar.