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* ; Humans ; Apicoectomy ; Contraindications, Procedure ; Tooth Apex/diagnostic imaging* ; Postoperative Complications/prevention & control* ; Consensus ; Treatment Outcome

Pulpotomy, which belongs to vital pulp therapy, has become a strategy for managing pulpitis in recent decades. This minimally invasive treatment reflects the recognition of preserving healthy dental pulp and optimizing long-term patient-centered outcomes. Pulpotomy is categorized into partial pulpotomy (PP), the removal of a partial segment of the coronal pulp tissue, and full pulpotomy (FP), the removal of whole coronal pulp, which is followed by applying the biomaterials onto the remaining pulp tissue and ultimately restoring the tooth. Procedural decisions for the amount of pulp tissue removal or retention depend on the diagnostic of pulp vitality, the overall treatment plan, the patient's general health status, and pulp inflammation reassessment during operation. This statement represents the consensus of an expert committee convened by the Society of Cariology and Endodontics, Chinese Stomatological Association. It addresses the current evidence to support the application of pulpotomy as a potential alternative to root canal treatment (RCT) on mature permanent teeth with pulpitis from a biological basis, the development of capping biomaterial, and the diagnostic considerations to evidence-based medicine. This expert statement intends to provide a clinical protocol of pulpotomy, which facilitates practitioners in choosing the optimal procedure and increasing their confidence in this rapidly evolving field.
Humans ; Calcium Compounds/therapeutic use* ; Consensus ; Dental Pulp ; Dentition, Permanent ; Oxides/therapeutic use* ; Pulpitis/therapy* ; Pulpotomy/standards*

Intentional tooth replantation (ITR) is an advanced treatment modality and the procedure of last resort for preserving teeth with inaccessible endodontic or resorptive lesions. ITR is defined as the deliberate extraction of a tooth; evaluation of the root surface, endodontic manipulation, and repair; and placement of the tooth back into its original socket. Case reports, case series, cohort studies, and randomized controlled trials have demonstrated the efficacy of ITR in the retention of natural teeth that are untreatable or difficult to manage with root canal treatment or endodontic microsurgery. However, variations in clinical protocols for ITR exist due to the empirical nature of the original protocols and rapid advancements in the field of oral biology and dental materials. This heterogeneity in protocols may cause confusion among dental practitioners; therefore, guidelines and considerations for ITR should be explicated. This expert consensus discusses the biological foundation of ITR, the available clinical protocols and current status of ITR in treating teeth with refractory apical periodontitis or anatomical aberration, and the main complications of this treatment, aiming to refine the clinical management of ITR in accordance with the progress of basic research and clinical studies; the findings suggest that ITR may become a more consistent evidence-based option in dental treatment.
Humans ; Tooth Replantation/methods* ; Consensus ; Periapical Periodontitis/surgery*

Instrument separation is a critical complication during root canal therapy, impacting treatment success and long-term tooth preservation. The etiology of instrument separation is multifactorial, involving the intricate anatomy of the root canal system, instrument-related factors, and instrumentation techniques. Instrument separation can hinder thorough cleaning, shaping, and obturation of the root canal, posing challenges to successful treatment outcomes. Although retrieval of separated instrument is often feasible, it carries risks including perforation, excessive removal of tooth structure and root fractures. Effective management of separated instruments requires a comprehensive understanding of the contributing factors, meticulous preoperative assessment, and precise evaluation of the retrieval difficulty. The application of appropriate retrieval techniques is essential to minimize complications and optimize clinical outcomes. The current manuscript provides a framework for understanding the causes, risk factors, and clinical management principles of instrument separation. By integrating effective strategies, endodontists can enhance decision-making, improve endodontic treatment success and ensure the preservation of natural dentition.
Humans ; Root Canal Therapy/adverse effects* ; Consensus ; Root Canal Preparation/adverse effects*

Objective:To discuss the effect of long-term use of chlorhexidine on the resistance of Enterococcus faecalis(E.faecalis),and to clarify its mechanism.Methods:The standard strain of E.faecalis was repeatedly exposed to chlorhexidine for 10 generations,and the minimum inhibitory concentration(MIC)was recorded at each passage.The bacteria collected from the 10th generation with increased MIC values were designated as the E.faecalis chlorhexidine-resistant strains(E.faecalis-Cs).The growth curves of two strains were drawn;the morphology of two strains were observed by transmission electron microscope;the number of biofilm formation of two strains was detected by crystal violet staining;the bacterial hydrophobicities of two strains were detected by microbial adhesion to hydrocarbons(MATH)method;the expression levels of S-ribosylhomocysteine lyase(LuxS)mRNA in the bacterial biofilms of two strains were detected by real-time fluorescence quantitative PCR(RT-qPCR)method.Results:From the 0th to the 10th generation,the MIC values of E.faecalis were gradually increased.The growth curves of E.faecalis and E.faecalis-Cs showed no significant differences.The transmission electron microscope observation results showed that both E.faecalis and E.faecalis-Cs appeared oval or diplococcal,with intact cell wall structures,smooth edges,and evenly distributed cytoplasm.There were no significant differences in the morphology,size,cell wall thickness,or integrity between two types of bacteria.The crystal violet staining results showed that compared with E.faecalis,the number of biofilm formation of E.faecalis-Cs was significantly increased(P<0.05).The MATH results showed tha the hydrophobicity of E.faecalis-Cs was significantly higher than that of E.faecalis(P<0.05).The RT-qPCR results showed that the expression level of LuxS mRNA in the biofilms of E.faecalis-Cs was significantly higher than that of E.faecalis(P<0.05).Conclusion:E.faecalis develops the resistance after repeated exposure to the chlorhexidine,and the pathogenicity of the resistant strain is enhanced.The high expressin of quorum sensing(QS)system LuxS gene and stronger biofilm forming ability of bacteria may be the potential mechanism for E.faecalis to tolerate the chlorhexidine.

Objective:To analyze the root canal diameter of the mandibular first premolar by using finite element analysis to simulate the stress distribution of dentin under three different preparation methods,and to provide the basis for clinical root canal preparation strategies of the mandibular first premolars.Methods:Twenty-one patients with complete cone beam computed tomography(CBCT)images were selected.The original DICOM format data from CBCT were imported into Mimics 21.0 software to measure the root canal diameter at 3,6,9,and 12 mm from the apex and the root canal taper was segmentally calculated.Based on this,three-dimensional finite element models of the dental and periodontal tissues were constructed.Control group,maximum diameter preparation group,uniform preparation group,and 0.06 taper instrument preparation group were designed.In ANSYS Workbench 17.0 finite element analysis software,a 200 N load was applied to the buccal,lingual,and occlusal surfaces in various groups,and the stresses on dentin in various groups were analyzed.Results:The analysis of root canal taper at 3-6 mm,6-9 mm,and 9-12 mm from the apex of mandibular first premolar teeth showed that the taper was similar in the mesial-distal direction at 3-6 mm from the apex.The average taper in the buccal-lingual direction at 6-9 mm from the apex was 0.29,which was greater than the taper in the apical 1/3 and coronal 1/3.Under the same load,the peak stress values in dentin of mandibular first premolar teech in various groups were increased sequentially:4.693 6,16.304 0,14.278 0,and 18.682 0 MPa.The stress in maximum diameter preparation group concentrated on the canal wall with the highest stress value.The stress in uniform preparation group concentrated on the root surface,and the stress values on each section were lower than those in maximum diameter preparation group.The stress in 0.06 taper instrument preparation group concentrated on the apical 1/3 of the root surface.Conclusion:The root canal of the mandibular first premolar has a unique elliptical taper shape,and there are significant differences in diameter and taper between the mesial-distal and buccal-lingual directions.Different preparation methods result in different stress distributions on the canal wall,and the uniform preparation is the best method for enlarging the canal.

External apical root resorption is among the most common risks of orthodontic treatment, and it cannot be completely avoided and predicted. Risk factors causing orthodontic root resorption can generally be divided into patient- and treatment-related factors. Root resorption that occurs during orthodontic treatment is usually detected by radiographical examination. Mild or moderate root absorption usually does no obvious harm, but close attention is required. When severe root resorption occurs, it is generally recommended to suspend the treatment for 3 months for the cementum to be restored. To unify the risk factors of orthodontic root resorption and its clinical suggestions, we summarized the theoretical knowledge and clinical experience of more than 20 authoritative experts in orthodontics and related fields in China. After discussion and summarization, this consensus was made to provide reference for orthodontic clinical practice.
Humans ; Tooth Movement Techniques/adverse effects* ; Root Resorption/etiology* ; Consensus ; Dental Cementum ; Risk Factors

BACKGROUNDInsulin resistance (IR) plays an important pathophysiological role in the development of diabetes, dyslipidemia, hypertension, and cardiovascular disease. Moreover, IR can occur even in non-obese people without diabetes. However, direct detection of IR is complicated. In order to find a simple surrogate marker of IR early in non-obese people, we investigate the association of commonly-used biochemical markers (liver enzymes and lipid profiles) with IR in urban middle-aged and older non-obese Chinese without diabetes.

METHODSThis cross-sectional study included 1 987 subjects (1 473 women). Fasting blood samples were collected for measurement of glucose, insulin, liver enzymes, lipid profiles and creatinine. Subjects whose homeostasis model of assessment-IR (HOMA-IR) index values exceeded the 75th percentile (2.67 for women and 2.48 for men) of the population were considered to have IR. The area under the receiver operating characteristic curve (ROC) was used to compare the power of potential markers in identifying IR.

RESULTSTriglycerides (TG) and ratio of TG to high-density lipoprotein cholesterol (TG/HDL-C) discriminated IR better than other indexes for both sexes; areas under the receiver operating characteristic (ROC) curves (AUC) values were 0.770 (95% confidence interval 0.733-0.807) and 0.772 (0.736-0.809), respectively, for women and 0.754 (0.664-0.844) and 0.756 (0.672-0.840), respectively, for men. To identify IR, the optimal cut-offs for TG and TG/HDL-C ratio were 1.315 mmol/L (sensitivity 74.3%, specificity 71.0%) and 0.873 (sensitivity 70.1%, specificity 73.4%), respectively, for women, and 1.275 mmol/L (sensitivity 66.7%, specificity 74.4%) and 0.812 (sensitivity 75.8%, specificity 69.2%), respectively, for men.

CONCLUSIONTG and TG/HDL-C ratio could be used to identify IR in urban middle-aged and older non-obese Chinese without diabetes.

Aged ; Alanine Transaminase ; blood ; Aspartate Aminotransferases ; blood ; Cholesterol, HDL ; blood ; Cross-Sectional Studies ; Diabetes Mellitus ; blood ; Female ; Humans ; Insulin Resistance ; physiology ; Liver ; enzymology ; Male ; Middle Aged ; Triglycerides ; blood

OBJECTIVE: To investigate the involvement of ephrinB2 in periodontal tissue remodeling in compression areas during orthodontic tooth movement and the effects of compressive force on EphB4 and ephrinB2 expression in osteoblasts and osteoclasts. METHODS: A rat model of experimental tooth movement was established to examine the histological changes and the localization of ephrinB2 in compressed periodontal tissues during experimental tooth movement. RAW264.7 cells and ST2 cells, used as precursor cells of osteoclasts and osteoblasts, respectively, were subjected to compressive force in vitro. The gene expression of EphB4 and ephrinB2, as well as bone-associated factors including Runx2, Sp7, NFATc1, and calcitonin receptor, were examined by quantitative real-time polymerase chain reaction (PCR). RESULTS: Histological examination of the compression areas of alveolar bone from experimental rats showed that osteoclastogenic activities were promoted while osteogenic activities were inhibited. Immunohistochemistry revealed that ephrinB2 was strongly expressed in osteoclasts in these areas. Quantitative real-time PCR showed that mRNA levels of NFATc1, calcitonin receptor, and ephrinB2 were increased significantly in compressed RAW264.7 cells, and the expression of ephrinB2, EphB4, Sp7, and Runx2 was decreased significantly in compressed ST2 cells. CONCLUSIONS: Our results indicate that compressive force can regulate EphB4 and ephrinB2 expression in osteoblasts and osteoclasts, which might contribute to alveolar bone resorption in compression areas during orthodontic tooth movement.
Animals ; Bone Resorption* ; Gene Expression ; Immunohistochemistry ; Models, Animal ; Osteoblasts* ; Osteoclasts* ; Rats ; Real-Time Polymerase Chain Reaction ; Receptors, Calcitonin ; RNA, Messenger ; Tooth Movement*

Objective To inveatigate the effect of 15-HETE, a metabolite of arachidonic acid, on isolated hypoxic pulmonary arterial ringa ( PARs) , trying to find appropriate treatment for pulmonary hypertension and its complications during anesthesia in order to avoid hypoxemia. Methods Sixteen healthy Wistar rats of either sex weighing (230 ? 10) g were randomly divided into two groups : A control group breathing fresh air (FiO2 =21%) and B hypoxia group breathing hypoxic air (N2 = 90% , O2 = 10% ) in a hypoxic box. After breathing hypoxic air for 9 days the animals were anesthetized. Heart and lungs were immediately removed and PARs (0.5-1.0 mm in diameter and 3 mm in length) were prepared. Four PARs were prepared from each animal. The PARs were suspended in baths filled with Krebs-Hensleit (K-H) solution maintained at 37℃ and aerated with 95% O2 and 5% CO2. Preload was gradually increased to 0.3 g in 30 min. The isometric tension was measured using a four-channel force-displacement transducer. 15-HETE was added to K-H solution and the concentration was gradually increased from 10-8 to 10-6 mol?L-1 at 5 min intervals. Contractility of PARs was analyzed by a software of Medlab 6.0. Concentration-tension curve was drawn and contraction rates were calculated. 2 mmol?L-1 4-AP, 10-2 mol?L-1 TEA and 10-6 mol?L-1 GLYB were added to separate K-H solution baths and 40 min later 15-HETE was added in order to detennine the effect of difierent potassium channel blockers on contraction response of PARs to 15-HETE. Results With increasing concentration from 10-8 to 10-6 mol?L-1 , 15-HETE increased PARs tension gradually in a dose-dependent manner from 106% ?6% to 139% ? 4% in group A and from 113% ?6% to 163% ?6% in group B. The difference in PARs tension between group A and B was statistically significant (P