Introduction To investigate the biomechanical characteristics of innate occlusal contact patterns in cracked teeth (CT) using T-Scan analysis combined with finite element analysis (FEA), and to establish a theoretical foundation for clinical prevention and restorative strategies. Methods Twelve patients with cracked maxillary first molars (MFMs) exhibiting mesial marginal ridge cracks and twelve controls were enrolled. Occlusal contacts were recorded using T-Scan, with categorical variables analyzed via Fisher’s exact test (p < 0.05). Patient-specific finite element models were constructed from CBCT data of three cracked and three intact MFMs. Stress distribution under different loadings was compared using two-way ANOVA (p < 0.05). Results T-Scan analysis demonstrated a significantly higher incidence of abnormal occlusal contact points in the CT group compared with controls (p < 0.05), along with bilateral occlusal imbalance. FEA revealed that maximum von Mises stress values on the mesial surfaces were consistently higher than those on the distal surfaces in the CT group under vertical loading (p < 0.05). Abnormal contact sites contributed to increased stress on the mesial surfaces in both CT and controls. A significant intergroup difference in maximum von Mises stress was observed on the mesial surfaces (p < 0.05), whereas no significant difference was detected on the distal surfaces. Conclusions Patients with CT exhibited bilateral occlusal imbalance, characterized by abnormal occlusal contact points on the affected teeth. Congenital morphological discrepancies represent the primary etiological factor for CT, whereas aberrant contact points further exacerbate crack progression. Early occlusal adjustment and crown-supported protection is recommended to compensate for underlying morphological abnormalities.

Digital guided therapy (DGT) has been advocated as a contemporary computer-aided technique for treating endodontic diseases in recent decades. The concept of DGT for endodontic diseases is categorized into static guided endodontics (SGE), necessitating a meticulously designed template, and dynamic guided endodontics (DGE), which utilizes an optical triangulation tracking system. Based on cone-beam computed tomography (CBCT) images superimposed with or without oral scan (OS) data, a virtual template is crafted through software and subsequently translated into a 3-dimensional (3D) printing for SGE, while the system guides the drilling path with a real-time navigation in DGE. DGT was reported to resolve a series of challenging endodontic cases, including teeth with pulp obliteration, teeth with anatomical abnormalities, teeth requiring retreatment, posterior teeth needing endodontic microsurgery, and tooth autotransplantation. Case reports and basic researches all demonstrate that DGT stand as a precise, time-saving, and minimally invasive approach in contrast to conventional freehand method. This expert consensus mainly introduces the case selection, general workflow, evaluation, and impact factor of DGT, which could provide an alternative working strategy in endodontic treatment.

This study aimed to predict the fracture resistance of a mandibular first molar (MFM) with diverse endodontic cavities using finite element analysis (FEA). Five experimental finite element models representing a natural tooth (NT) and 4 endodontically treated MFMs were generated. Treated MFM models were with a traditional endodontic cavity (TEC) and minimally invasive endodontic (MIE) cavities, including guided endodontic cavity (GEC), contracted endodontic cavity (CEC) and truss endodontic cavity (TREC). Three loads were applied, simulating a maximum bite force of 600 N (N) vertically and a normal masticatory force of 225 N vertically and laterally. The distributions of von Mises (VM) stress and maximum VM stress were calculated. The maximum VM stresses of the NT model were the lowest under normal masticatory forces. In endodontically treated models, the distribution of VM stress in GEC model was the most similar to NT model. The maximum VM stresses of the GEC and CEC models under different forces were lower than those of TREC and TEC models. Under vertical loads, the maximum VM stresses of the TREC model were the highest, while under the lateral load, the maximum VM stress of the TEC model was the highest. The stress distribution of tooth with GEC was most like NT. Compared with TECs, GECs and CECs may better maintain fracture resistance, TRECs, however, may have a limited effect on maintenance of the tooth resistance.

Objective To investigate the distribution characteristics and functional genes of cariogenic bacteria in oral microorganisms of patients with type 2 diabetes mellitus and to improve the understanding of the relationship between type 2 diabetes mellitus and dental caries. Methods The experimental group included 10 patients with type 2 diabetes treated in the Department of Endocrinology, the First Affiliated Hospital of Air Force Medical University. The normal control group included healthy oral subjects without type 2 diabetes in the community population (10 cases). Samples of supragingival plaque from patients with type 2 diabetes mellitus and normal controls were collected and sequenced. Bioinformatics and statistical analysis of cariogenic bacteria such as Streptococcus mutans, Lactobacillus, Actinomyces viscosus and Candida albicans were carried out. Results There were slightly fewer cariogenic bacteria such as Streptococcus mutans, Lactobacillus, Actinomyces viscosus and Candida albicans in supragingival plaque samples of type 2 diabetic patients than in normal controls, but the difference was not statistically significant (P>0.05). The results of KEGG pathway functional metabolic differences showed that the metabolic pathways of D-arginine and D-ornithine metabolism, biofilm formation-Escherichia coli, carolactam degradation and arginine biosynthesis were more abundant in the T2DM group than in the normal control group, while metabolic pathways such as tyrosine metabolism, selenocompound metabolism and pyruvate metabolism showed the opposite trend. Conclusion There was no significant difference in the content of cariogenic microorganisms between type 2 diabetic patients and normal control group. The differential metabolic pathways of the functional genes indicated that an increase in the arginine metabolic pathway was beneficial to the maintenance of acid-base balance in the oral microecological environment.

以粘接固位为基础的后牙冠方修复是一种更加保守且生存率高的修复方式,目前己被广泛应用.该文以多数学者提出的基牙预备原则和研究为基础,结合实际临床操作病例,从患牙的术前分析、去除龋坏组织、剩余牙体组织分析和抗力形预备、修复空间预备、即刻牙本质封闭和洞形优化设计这些临床操作步骤来介召后牙大面积缺损粘接间接修复牙体预备的规范化操作过程.

Objective:The aim of this retrospective study was to evaluate the prevalence of taurodontism in a group of adult dental patients in Northwest China with the aid of cone-beam computed tomography (CBCT). Methods:This study used Shifman and Chanannel's criteria to statistically analyze the prevalence of taurodontism in the premolars and molars of the Chinese population. CBCT images of 5488 teeth from 580 subjects of Chinese origin were evaluated. The measured data were statistically analyzed and the chi-square test was also used to compare the prevalence of taurodontism between male and female subjects and between the upper and lower jaws (P < 0.05). Results:Taurodontism was detected in 169 patients, with a prevalence of 29.14%, of which 27.24% were males and 30.65% were females. The chi-square test showed that there was no significant difference between males and females (P > 0.05). Taurodontism was found in 7.45% of all teeth examined. Taurodonts were significantly more common in the maxilla (9.06%) than in the mandible (5.15%) (P < 0.001), and the maxillary second molar (25.18%) was the most common tooth affected. According to morphology, hypotaurodonts were the most common (60.39%) among taurodontic teeth. Conclusions:Taurodontism was relatively common in the Chinese population and was almost equally distributed between males and females. The maxillary second molar was the most common tooth of all taurodonts measured, and taurodonts were significantly more common in the maxilla than in the mandible. Hypotaurodontism was the most common form of taurodontism. Our study provides a reference for dental deformities in the Chinese population and the diagnosis and treatment of taurodontism.

Several previous studies have shown that oral microbial disorders may be closely related to the occurrence and development of type 2 diabetes mellitus (T2DM). However, whether the function of oral microorganisms and their metabolites have changed in patients with T2DM who have not suffered from any oral diseases has not been reported. We performed metagenomic analyses and nontargeted metabolic analysis of saliva and supragingival plaque samples from patients with T2DM who have not suffered any oral diseases and normal controls. We found that periodontal pathogens such as Porphyromonas gingivalis and Prevotella melaninogenica were significantly enriched, while the abundances of dental caries pathogens such as Streptococcus mutans and Streptococcus sobrinus were not significantly different in patients with T2DM compared to those in normal controls. Metabolomic analyses showed that the salivary levels of cadaverine and L-(+)-leucine of patients with T2DM were significantly higher than those of normal controls, while the supragingival plaque levels of N-acetyldopamine and 3,4-dimethylbenzoic acid in patients with T2DM were significantly higher than those in the normal controls. Additionally, we identified the types of oral microorganisms related to the changes in the levels of circulating metabolites, and the oral microorganisms were involved in the dysregulation of harmful metabolites such as cadaverine and n, n-dimethylarginine. Overall, our study first described the changes in the composition of oral microorganisms and their metabolites in patients with T2DM who have not suffered any oral diseases, which will provide a direct basis for finding oral biomarkers for early warning of oral diseases in T2DM. IMPORTANCE The incidence of oral diseases in type 2 diabetic patients might increase, and the severity might also be more serious. At present, the relationship between oral microorganisms and type 2 diabetes mellitus (T2DM) has become a hot topic in systemic health research. However, whether the function of oral microorganisms and their metabolites have changed in patients with T2DM who have not suffered from any oral diseases has not been reported. We found that even if the oral condition of T2DM is healthy, their oral microbes and metabolites have changed, thus increasing the risk of periodontal disease. Our study first described the changes in the composition of oral microorganisms and their metabolites in T2DM who have not suffered any oral diseases and revealed the correlation between oral microorganisms and their metabolites, which will provide a direct basis for finding oral biomarkers for early warning of oral diseases in patients with T2DM.

BACKGROUND:Fused teeth usually involve several complications, such as the development of caries in the groove between fused crowns, tooth impaction, diastemas, aesthetic and periodontal problems, and pulpal pathosis, due to the complex anatomical structure of fused teeth. A thorough diagnosis is paramount to forming an accurate treatment plan and obtaining a favourable prognosis. With the advent of cone-beam computed tomography (CBCT), accurate 3-dimensional images of teeth and their surrounding dentoalveolar structures can now be readily obtained, and the technology can accurately provide a minimally invasive approach to acquire detailed diagnostic information. Therefore, we utilize CBCT data herein to generate a digital model for the infected region in a patient, and this model enables us to better plan the management of his case.CASE SUMMARY:This report details the diagnosis and endodontic treatment of a rare case involving a fused maxillary second molar and two paramolars with apical periodontitis. The patient experienced pain upon biting and cold sensitivity in the area of the maxillary left molar. No caries or other defects were identified in these teeth, and a normal response to a pulp electric viability test was observed. With the aid of CBCT and digital model technology, we initially suspected that the infection originated from the isthmus between the maxillary second molar and two paramolars. Therefore, we only treated the isthmus by an endodontic approach and did not destroy the original tooth structure; furthermore, the vital pulp was retained, and good treatment outcomes were observed at the 24-month follow-up.CONCLUSION:This finding may provide new insights and perspectives on the diagnosis and treatment of fused teeth.

Abstract Objectives: The purpose of this study was to predict the fracture resistance of endodontically treated mandibular first molars (MFMs) with diverse minimally invasive endodontic access cavities using finite element models.Materials and Methods: Based on microcomputed tomographic data of an MFM, five three-dimensional finite element models representing a natural tooth (NT) and 4 endodontically treated MFMs were generated using finite element analysis software (HyperWork 14.0, Altair, USA). Treated MFM models were with a traditional endodontic cavity (TEC) and minimal invasive endodontic (MIE) cavities, including a computer-aided designed guided endodontic cavity (GEC), contracted endodontic cavity (CEC) and truss endodontic cavity (TREC). Three loading conditions were applied, simulating a maximum bite force of 600 N vertically and a normal masticatory force of 225 N vertically and laterally. The distributions of von Mises (VM) stress and peak VM stress were calculated.Results: The peak VM stresses of the NT model were the lowest under normal masticatory forces. In endodontically treated models, the distribution of VM stress in GEC model under all loads was the most similar to NT model. The peak VM stresses of the GEC and CEC models under different forces were lower than those of TREC and TEC models. The peak VM stresses of the GEC were lower than those of the CEC under normal masticatory loads but higher under maximum bite load. Under two vertical loads, the peak VM stresses of the TREC model were the highest, while under the lateral load, the peak VM stress of the TEC model was the highest. However, the VM stress in most part of the TEC model was higher than that in TREC model under all loads. Conclusions: Compared with TEC, GEC and CEC could better improve the fracture resistance of teeth. TREC may have a limited effect on fracture resistance enhancement when compared to GEC and CEC.Clinical Relevance: Our data demonstrated that compared with TEC and TREC, GEC and CEC access could better improve the fracture resistance of endodontically treated teeth, which may be an alternative balancing biomechanical properties and clinical convenience.

Objective Metagenomic sequencing was used to explore the species composition and internal functional metabolic pathway of saliva and supragingival plaque microbial communities in healthy adults to provide a theoretical reference for the biological prevention and treatment of oral diseases. Methods Saliva and supragingival plaque samples were collected from healthy adults, total DNA was extracted, and a metagenomic library was constructed. The qualified library was sequenced via metagenomics, and the sequencing data were analyzed using bioinformatics and statistics. Results The main bacterial phyla in healthy oral samples were Proteobacteria (32.51%), Bacteroidetes (30.81%), and Actinobacteria (16.23%), and the main bacterial species were Corynebacterium matruchotii (3.84%), Haemophilus parainfluenzae (2.91%), and Prevotella melaninogenica (2.76%). The alpha diversity of the supragingival plaque group was higher than that of the saliva group, and there was a significant difference in the composition of the microbial community between the two groups (P<0.05). At the species level, Prevotella melaninogenica, Fusobacterium periodonticum, and Prevotella intermedia were more abundant in saliva samples than in supragingival plaque samples, while Corynebacterium matruchotii, Propionibacterium acidifaciens, and Rothia dentocariosa were more abundant in supragingival plaque samples than in saliva samples (P<0.05). High-quality gene sets of saliva and supragingival plaque in healthy adults were constructed based on metagenomic sequencing. The results of KEGG pathway functional metabolic differences showed that starch and sucrose metabolism, leucine and isoleucine degradation, and arginine biosynthesis in salivary microorganisms were more abundant than in supragingival plaque, while glycolysis/gluconeogenesis and carbon metabolism in supragingival plaque were more abundant than in saliva. Conclusion There are significant differences in the species composition and functional gene metabolic pathways of saliva and supragingival plaque microecology in healthy adults. The sensitivity of dominant species in different microecological regions to the identification of oral diseases may be different. In the microbiological study of oral diseases, appropriate samples should be selected according to different diseases.

Objective To explore the key points of clinical diagnosis and treatment of three mesiobuccal root canals. Methods In the procedure of endodontic therapy for the upper left second molar with pulpitis, through root canal exploration under a dental microscope and cone beam CT (CBCT)-assisted imaging examination, it was confirmed that the left upper second molar contained 3 roots and 5 root canals, among which the third root canal existed in the mesiobuccal root. Combined with perfect root canal preparation, cleaning, disinfection, filling and minimally invasive inlay repair, the clinical symptoms were eliminated. The patients were followed up and the related literatures were reviewed. Results One- and two-year follow-ups showed that the tooth had no discomfort and could be used normally. X-ray revealed that the filling was complete, and the periapical tissue was normal. The results of the literature review showed that the incidence of three mesiobuccal root canals in maxillary second molars was 0.11%-4.2%. It is difficult to find additional root canals only by X-ray imaging. Dentists should further determine the number and anatomical shape of root canals by CBCT and operating microscopy. When there are three mesiobuccal root canals in maxillary molars, dentists should avoid overpreparation. Healthy tooth tissue is the key to good prognosis. Conclusion During root canal therapy, clinicians should consider the anatomical variation of the root canal, should always be alert to the existence of an extra root canal, and should use CBCT, operating microscopy, ultrasound and various auxiliary instruments to locate and treat the variant root canal.

Aim To evaluate in a laboratory setting, the impact of three designs of endodontic access cavities on dentine removal and effectiveness of canal instrumentation in extracted maxillary first molars using micro-computed tomography (micro-CT). Methodology A total of 30 extracted intact maxillary first molars were selected and scanned by micro-CT with a voxel size of 24 mu m and randomly distributed into three groups: the traditional endodontic cavity (TEC) group, the conservative endodontic cavity (CEC) group and the guided endodontic cavity (GEC) group. The pulp chambers of teeth in the groups were accessed accordingly. After root canal preparation, the teeth were rescanned. The volume of dentine removed after canal preparation, the noninstrumented canal areas, canal transportation and centring ratio were analysed. Data were analysed statistically using one-way analysis of variance. Tukey's post hoc test was used for multiple comparisons. The significance level was set at p The total volume of dentine removed was significantly greater in the TEC group after root canal preparation (p < .05). No significant differences in the volume of dentine removed occurred between the CEC and GEC groups (p > .05). The volume of dentine removed in the crown, pericervical dentine and coronal third of the canal was significantly lower in CEC and GEC groups when compared to that in the TEC group (p < .05), no difference was observed in the middle third of the canal and apical third of the canal amongst the three groups (p > .05). There was no significant difference in noninstrumented canal area, canal transportation and centring ratio amongst the TEC, CEC and GEC groups (p > .05). Conclusions In extracted maxillary molars tested in a laboratory setting, CEC and GEC preserved more tooth tissue in the crown, pericervical dentine and coronal third of the canal compared with TEC after root canal preparation. The design of the endodontic access cavity did not impact on the effectiveness of canal instrumentation in terms of noninstrumented canal area, canal transportation and centring ratio.

To evaluate in a laboratory setting, the impact of three designs of endodontic access cavities on dentine removal and effectiveness of canal instrumentation in extracted maxillary first molars using micro-computed tomography (micro-CT). A total of 30 extracted intact maxillary first molars were selected and scanned by micro-CT with a voxel size of 24 µm and randomly distributed into three groups: the traditional endodontic cavity (TEC) group, the conservative endodontic cavity (CEC) group and the guided endodontic cavity (GEC) group. The pulp chambers of teeth in the groups were accessed accordingly. After root canal preparation, the teeth were rescanned. The volume of dentine removed after canal preparation, the noninstrumented canal areas, canal transportation and centring ratio were analysed. Data were analysed statistically using one-way analysis of variance. Tukey's post hoc test was used for multiple comparisons. The significance level was set at p < .05. The total volume of dentine removed was significantly greater in the TEC group after root canal preparation ( p < .05). No significant differences in the volume of dentine removed occurred between the CEC and GEC groups ( p > .05). The volume of dentine removed in the crown, pericervical dentine and coronal third of the canal was significantly lower in CEC and GEC groups when compared to that in the TEC group ( p < .05), no difference was observed in the middle third of the canal and apical third of the canal amongst the three groups ( p > .05). There was no significant difference in noninstrumented canal area, canal transportation and centring ratio amongst the TEC, CEC and GEC groups ( p > .05). In extracted maxillary molars tested in a laboratory setting, CEC and GEC preserved more tooth tissue in the crown, pericervical dentine and coronal third of the canal compared with TEC after root canal preparation. The design of the endodontic access cavity did not impact on the effectiveness of canal instrumentation in terms of noninstrumented canal area, canal transportation and centring ratio.

目的 探讨微课结合翻转课堂的教学模式在牙体牙髓病学实践教学效果中的作用.方法 选择第四军医大学口腔医院2016级所有23名五年制口腔医学专业本科生作为实验组,2015级所有20名五年制口腔医学专业本科生作为对照组,实验组在牙体牙髓病学实践教学中采用微课结合翻转课堂的教学模式,对照组采用传统教学法,研究起始时间为2019年9月至2021年1月.课程结束后比较两组学生实践理论和实践操作的成绩,并通过问卷调查评估实验组学生对微课结合翻转课堂的教学模式的认可度和满意度.结果 实验组实践成绩和总成绩均高于对照组,两组之间差异有统计学意义(P<0.05).问卷调查结果显示实验组学生对微课结合翻转课堂的教学模式具有较高的认可度和满意度,但也认为其不能完全替代传统的教学方法.结论 微课结合翻转课堂的新型教学模式有利于调动学生的学习积极性,提高教学效率,是提升牙体牙髓病学实践教学效果的一种有效方法.

Minimally invasive endodontics (MIE) can preserve dental tissue to a greater extent and improve the success rate of endodontics and has thus attracted increasing attention. 3D printing is a technology that is based on a digital model and uses powdered metal, plastic and other materials to construct objects by printing layer by layer. This article reviews the application of 3D printing technology in minimally invasive endodontics to provide a reference for the application of 3D printing technology in clinical minimally invasive endodontics in the future. In recent years, 3D printing technology has been widely used in various professional fields of stomatology, such as maxillofacial surgery, prosthodontics, and orthodontics. Using cone beam computed tomography (CBCT) and oral scanners to obtain accurate data on the internal and external structures of teeth combined with 3D printing to construct a tooth diagnostic model and pulp opening guide plate, we can accurately locate the position of the root canal and provide a new method for minimally invasive endodontics. At present, 3D printing technology is mainly used to guide the pulp opening pathway, assist in the minimally invasive treatment of malformed teeth and calcified root canals, and assist with apical surgery in the field of minimally invasive endodontics. However, its accuracy and clinical prognosis still need to be verified with a large number of clinical cases.

宏基因组是指环境中所有微生物的遗传物质总和.宏基因组学技术可以最大限度地利用环境中的微生物资源,受到了国内外微生物研究者的重点关注.口腔中寄居着大量的微生物群落,以往对口腔疾病微生物的研究大多局限于单纯的细菌培养技术,然而,由于培养技术的局限性,部分微生物很难或根本不能培养,宏基因组学技术打破了这一局限性,帮助人类发掘更丰富的口腔微生物资源.最近,以宏基因组学测序为基础的研究描绘出了口腔生态系统的图谱,越来越多的实验证明口腔微生物组在各种口腔疾病甚至全身系统性疾病中的重要作用.同时,这也为基于人类微生物组的诊断和治疗开辟了新的途径.本综述旨在说明宏基因组学是研究人类口腔疾病及全身疾病相关微生物的得力工具,而且具有广阔的发展前景,同时也讨论了宏基因组学在应用中有待克服的局限性.

牙髓及根尖周疾病是牙体牙髓病科临床实践中最常见的疾病,根管治疗是治疗不可逆性牙髓炎及根尖周病首选的治疗方法.近年来,随着根管治疗器械及材料的不断发展,以及治疗手段的进步,微创牙髓病学(MIE)理念出现.MIE理念下的微创根管治疗不仅要求能控制感染,而且强调保留更多健康的牙体硬组织,追求提高牙齿长期留存率和正常功能的保存.其中,微创的髓腔预备方式对提高根管治疗后牙齿抗力起到十分重要的作用.

目的 利用三维有限元分析法评估不同根管通路建立方式对根管治疗后的下颌第一磨牙应力分布的影响.方法 利用完整的下颌第一磨牙的Micro-CT的扫描数据建立4组有限元模型:完整天然牙模型(A组)、紧凑型根管通路模型(B组)、传统开髓方式不建立直线通路模型(C组)、传统开髓方式建立直线通路模型(D组).B、C、D组在根管治疗后进行直接树脂充填.对以上模型施加4种不同静态压力,以计算和研究牙体组织应力分布及最大主应力值分布.结果 受垂直向咀嚼力时应力峰值:C组>D组>B组>A组,受水平向咀嚼力时应力峰值:B组>A组>C组>D组,受斜向咀嚼力时的应力峰值:D组>B组>C组>A组,受最大咬合力时的应力峰值:C组>D组>A组>B组.除应力加载点,应力集中区主要位于颈周牙本质(pericervical dentin,PCD).结论 采用紧凑型根管通路的下颌第一磨牙较传统型开髓方式抗折裂能力强.保留PCD可能无法增加牙齿整体抗力,但有利于提升牙齿长期留存率.

因龋坏、外伤、磨耗等原因造成的牙体缺损极为常见,对于一些用直接充填修复效果不佳的牙体缺损的患牙,我们通常使用间接修复体修复.临床上,我们常使用的间接修复体有嵌体修复和全冠修复.随着粘接技术的提升,嵌体,通过粘接及固位形修复,已作为现在临床常用的牙体缺损后的间接修复体之一.较全冠相比,它具有尽可能保存剩余牙体组织的优点而被优先选择,但仍需要有剩余的牙体组织来提供足够的抗力.嵌体可以使用不同的材料制作,如金属嵌体、瓷嵌体等.随着计算机辅助设计与制造(computer aided design/manufacturing,CAD/CAM)技术的兴起,全瓷材料也因为具有良好的生物相容性和易切削性被广泛应用.该文对牙体缺损的嵌体修复的分类、适应证和禁忌证、临床常见术后问题、嵌体修复材料种类等各方面的研究现状作一综述,期盼为牙体缺损的嵌体修复技术的临床应用和研究提供参考.

AIM:To observe the antimicrobial effect of Vibringe sonic root canal irrigator combined with so-dium hypochlorite on Enterococcus faecalis(E.faecalis) in root canal. METHODS:75 single-rooted human teeth in-fected with E.faecalis were randomly divided into 3 groups (n=25). From each group,5 samples were observed by scanning electron microscope,10 teeth were randomly selected and the dentin bacterial counts at different depths(0~100,100~200,200~300 μm) were measured and served as baseline data.The other 10 samples in each group were respectively treated with the Vibringe+52.5 g/L sodium hypochlorite (group A), syringe+52.5 g/L sodium hypo-chlorite (group B) and syringe + normal saline(group C). At last,the samples of root canal wall at different depths inside dentin tubules were collected. The bacterial reduction rates of each treatment were compared among groups and analyzed by one-way ANOVA.RESULTS:On the surface and at different depths inside dentin tubules,the bacteria clearance was more than 99% in group A and B,significantly greater than that in group C(P<0.05); group A vs group B,P>0.05. CONCLUSION:Vibringe root canal irrigator+52.5 g/L sodium hypochlorite can effectively e-liminate E.faecalis on the surface and at different depths inside dentin tubules,but it does not show obvious advantages to traditional syringe irrigation of 52.5g/L sodium hypochlorite.