联合方法测量工作长度应用于颌骨囊肿受累牙根管治疗的研究

目的：研究颌骨囊肿受累牙根管治疗中采用联合方法测量根管工作长度的效果。方法：选取36 例颌骨囊肿受累患牙需术前 根管治疗的患者,共135 颗患牙,186 个根管,随机分为两组,实验组（93 个根管）采用电测法联合纸尖法测量根管工作长度,对照 组（93 个根管）则采用电测法联合X 线法测量根管工作长度。对比两组根管充填后的充填效果。结果：实验组的根管恰填率为 90.32%,高于对照组的79.57%（P＜0.05）。结论：采用电测法联合纸尖法测量颌骨囊肿受累牙根管工作长度,准确率高,根管充填 效果好且安全。     

影响sc镍钛器械分离的相关因素分析

摘要 目的：分析影响sc镍钛器械分离的相关因素。方法：收集2020年1月至2022年4月在本院接受根管治疗的病例的离体牙。据研究目的和内容设计一般调查表收集临床资料。采用Schneider法测定根管弯曲度。结果：本次研究共收集到10047例病例,涉及22306个根管。其中236例病例（247根镍钛器械）发生器械分离,分离率为2.35%。其中有205例镍钛器械分离发生在磨牙,分离率为4.29%。有106例镍钛器械分离发生在上颌,分离率为1.83%;有130例镍钛器械分离发生在下颌,分离率为3.06%,两者相比差异具有统计学意义（x²=77.128,P<0.001）。轻度弯曲组镍钛器械分离率为0.32%,中度弯曲组镍钛器械分离率为1.04%,重度弯曲组镍钛器械分离组为3.46%,极重度弯曲组镍钛器械分离率为5.82%;随着根管弯曲度的增加,镍钛器械分离率呈明显上升趋势（z=291.883,P<0.001）。结论：sc镍钛器械分离率为2.35%,下颌磨牙根管预备中,器械分离发生率最高,根管弯曲度对器械分离发生也具有一定影响。     

青海地区藏汉族人群下颌第二磨牙根管形态的锥形束CT研究

目的:采用锥形束CT(Cone Beam CT,CBCT)技术探讨青海地区藏汉族人群下颌第二磨牙根管形态、数量以及C型根管发生率和髓腔差值的异同。方法:从2016年5月到2018年12月青大附院口腔门诊牙齿CBCT扫描结果中选择藏、汉民下颌第二磨牙各300颗,其中汉族150例,藏族150例。按照Vertucci分类对根管进行分型,探究青海地区藏、汉族人群下颌第二磨牙根管形态特点,同时对牙根类型、C型根管数量和发生率进行统计研究。结果:青海地区藏汉族人群下颌第二磨牙牙根类型以双根牙为主,且其在藏族人群中的发生率高于汉族人群。青海地区藏汉族人群下颌第二磨牙的根管分型以Ⅰ型和C型根管所占比例最高。在青海地区汉族人群和藏族人群下颌第二磨牙中,C形根管所占比率分别为40.7%和27.0%,汉族人群C型根管发生率显著高于藏族人群(P0.05)。在青海地区藏汉人群下颌第二磨牙中,女性的发生率显著高于男性(P0.05)。青海地区藏族人群的MB-DB、DB-P平均值显著高于汉族人群(P0.05)。结论:青海地区藏汉族人群下颌第二磨牙根管形态基本类似,C型根管发生率汉族人群是远远大于藏族人群的,具有一定的种族差异性。但是C型根管发生率在青海地区藏汉人群中都是女性大于男性。同时藏族人群髓腔差值也具有一定的种族差异性。     

A Cone-Beam Computed Tomographic Study on Mandibular First Molars in a Chinese Subpopulation

The purpose of this study was to conduct a cone-beam computed tomographic (CBCT) investigation on the root and canal configuration of the mandibular first molars, especially the morphology of the disto-lingual (DL) root, in a Chinese subpopulation. A total of 910 CBCT images of the mandibular first molars were collected from 455 patients who underwent CBCT examinations as a preoperative assessment for implants or orthodontic treatment. The following information was analyzed and evaluated: tooth position, gender, root and root canal number per tooth, root canal type of the mesial root(s) and distal root(s), angle of the DL root canal curvature, distance between two distal canal orifices in the teeth with DL root, and angle of disto-buccal canal orifice–disto-lingual canal orifice–mesio-lingual canal orifice (DB-DL-ML). Most of the mandibular first molars (64.9%, n = 591) had two roots with three root canals, and most of the mesial root canals (87.7%, n = 798) were type VI. The prevalence of the DL root was 22.1% (n = 201). The right side had a higher prevalence of DL root than the left side (p<0.05). Additionally, the curvature of the DL root canal were greater in the bucco-lingual (BL) orientation (30.10°±14.02°) than in the mesio-distal (MD) orientation (14.03°± 8.56°) (p<0.05). Overall there was a high prevalence of DL root in the mandibular first molars, and most of the DL roots were curved in different degrees. This study provided detailed information about the root canal morphology of the mandibular first molars in a Chinese subpopulation.     

Detection of Treponema denticola in root canal systems in primary and secondary endodontic infections. A correlation with clinical symptoms

AIM: The aim of the study was to investigate the presence of Treponema denticola in primary and secondary root-infected canal systems with periapical pathology and correlations with clinical signs and symptoms. METHODOLOGY: Endodontic samples were obtained from canals of 102 teeth: 79 had primary endodontic disease and 23 secondary endodontic disease. For each tooth, clinical data including symptoms and X-ray appearance were examined. The presence of T. denticola biological samples from the root canal space was detected by a PCR assay. RESULTS: T. denticola was detected in 24 out of the 79 teeth with primary infection and in 8 out of the 23 teeth with secondary infection. Teeth with specific clinical symptoms were frequently associated with T. denticola presence inside the root canal system. CONCLUSIONS: The presence of T. denticola in root canal system in association with specific clinical signs and symptoms of endodontic disease strongly suggests that this spirochete might play a critical role in the pathogenesis of the acute infection and rapid bone tissue alterations in both primary and secondary endodontic infections.     

两种根管冲洗液对狗牙根管内细菌抗菌作用的实验研究

目的观察2%洗必泰溶液和3%双氧水2种根管冲洗液对狗牙根管内粪肠球菌、溶血链球菌、微小消化链球菌、中间普氏菌及具核酸杆菌的影响,为临床根管治疗提供参考。方法选择成年健康杂种狗3只,共有24个实验牙,48个实验牙根。于狗牙根管内接种粪肠球菌、溶血链球菌、微小消化链球菌、中间普氏菌及具核酸杆菌。对狗牙完成根管治疗。于治疗后12个月拍摄根尖X线片,并记录牙齿和根尖周组织的临床表现。将患牙随机分为3组,每组7颗患牙,去除根管内充填物并进行根管预备,实验一组用2%洗必泰溶液冲洗根管,实验二组用3%双氧水冲洗根管,对照组用0.9%NaC l溶液冲洗根管。分别在根管预备前及根管预备冲洗后对根管内细菌取样,培养,鉴定并记录细菌菌落数量,测定根管内细菌变化情况。结果根管预备冲洗后3组根管内的细菌量均较根管预备前显著下降（P〈0.05）。2%洗必泰溶液和3%双氧水2种根管冲洗液的杀菌效果明显好于0.9%NaC l溶液（P〈0.05）,2%洗必泰溶液明显好于3%双氧水（P〈0.05）。结论2%洗必泰溶液是有效的根管冲洗药物,可明显减少狗牙根管内粪肠球菌、溶血链球菌、微小消化链球菌、中间普氏菌及具核酸杆菌的数量,但不能完全清除根管内的细菌。     

Endodontic considerations in the elderly

Tooth retention has increased significantly in older adults, and dentists are now challenged by the need to preserve critical teeth. There will be a need to consider endodontic therapy, and this paper describes how successful endodontics can be provided for elderly patients. Strategic treatment planning is essential, and preservation of key teeth will facilitate satisfactory oral function for elderly patients. These teeth may be important in achieving and maintaining an intact anterior dental arch, for removable partial denture retention or preservation of alveolar bone. In some cases, this can only be achieved if endodontic procedures are undertaken. When infection of a root canal is present, there is no reason why good quality endodontic therapy should not work in a healthy elderly patient. Elimination of infection can be challenging in narrow root canals, and a systematic approach for improving access into and negotiating these canals is outlined.     

不同根管器械去除弯曲根管内充填物的效果研究

目的:比较新型旋转器械马尼GPR和ProTaper再治疗系统、手用H锉在根管再治疗中去除弯曲根管内牙胶的清理效果。方法:选取30个弯曲度为30°的透明树脂根管模块,根管长度为17mm。使用ProTaper Next机用镍钛器械预备至30/.06,热压胶垂直加压根管充填。样本随机分为3组(n=10),用以下方法配合丁克除溶剂去除根管内充填材料,A组手用H锉、B组ProTaper再治疗系统和C组马尼GPR,记录去除充填物所用总时间。从颊舌向和近远中向2个角度拍着数码X线片,使用Image J 2X图像分析软件分析根管内充填物残留量。用天平称量推出根尖孔碎屑量。结果:ProTaper再治疗系统组根管壁充填物残留量明显多于马尼GPR组和H锉组(P0.05)。H锉组操作时间明显高于ProTaper再治疗系统组和马尼GPR组(P0.05)。马尼GPR组推出根尖孔碎屑量明显少于ProTaper再治疗系统组(P0.05)。结论:马尼再治疗锉去除根管内充填物效率优于ProTaper再治疗系统和H锉,机用镍钛器械所用时间明显少于手用器械。     

Three-dimensional observations of accessory canals in mature and developing rat molar teeth.

The structure, distribution and formation of accessory canals in the developing and mature molar teeth of rat mandibular jaws were investigated with scanning electron microscopy and with three-dimensional image analysis using serial light-microscopic sections. In the initial stage of the accessory canal formation, most of the canals appeared in the gaps of the epithelial root sheaths formed by their approaching each other in the initial stage of the root formation. However, some of the canals appeared in the slits which may be formed by the destruction of the epithelial root sheath in the root apex regions. When the gaps and slits were invaded by blood vessels, the regions surrounding the vessels did not mineralize but became accessory canals. Usually, an accessory canal with one blood vessel connected the periodontal ligament to the dental pulp; however, in some cases, the canals were broken off midway following the destruction of the vessels.     

奥硝唑用于感染根管消毒的细菌学研究

目的　观察和探讨新型抗厌氧菌药物奥硝唑消毒感染根管的抗菌效果。方法　选择感染根管患牙98颗,常规根管预备后,随机分为试验组(奥硝唑组)和对照组(甲醛甲酚组)各4 9颗。分别在根管预备前、预备后及封药后进行根管内细菌标本采样、培养、分离与鉴定,测定根管内细菌变化及检出情况,并观察封药后临床症状和体征的变化。结果　2组封药后,根管内细菌数量及检出率均较封药前明显降低( P<0 .0 5 ) ,根管内细菌数量及检出率比较,差异无显著性( P>0 .0 5 ) ,奥硝唑的近期临床疗效优于甲醛甲酚。结论　奥硝唑是一种较安全、有效的根管消毒药物     

Root elongation rate is correlated with the length of the bare root apex of maize and lupin roots despite contrasting responses of root growth to compact and dry soils

Background

We investigated interacting effects of matric potential and soil strength on root elongation of maize and lupin, and relations between root elongation rates and the length of bare (hairless) root apex.

Methods

Root elongation rates and the length of bare root apex were determined for maize and lupin seedlings in sandy loam soil of various matric potentials (?0.01 to ?1.6 MPa) and bulk densities (0.9 to 1.5 Mg m^?3).

Results

Root elongation rates slowed with both decreasing matric potential and increasing penetrometer resistance. Root elongation of maize slowed to 10 % of the unimpeded rate when penetrometer resistance increased to 2 MPa, whereas lupin elongated at about 40 % of the unimpeded rate. Maize root elongation rate was more sensitive to changes in matric potential in loosely packed soil (penetrometer resistances <1 MPa) than lupin. Despite these differing responses, root elongation rate of both species was linearly correlated with length of the bare root apex (r² 0.69 to 0.97).

Conclusion

Maize root elongation was more sensitive to changes in matric potential and mechanical impedance than lupin. Robust linear relationships between elongation rate and length of bare apex suggest good potential for estimating root elongation rates for excavated roots.     

Effect of SNP Polymorphisms of EDN1, EDNRA,and EDNRB Gene on Ischemic Stroke

The objective of this study is to investigate the association between SNP polymorphisms of endothelin-1 (EDN1) and endothelin receptor (EDNRA and EDNRB) gene and ischemic stroke (IS) in the Chinese Han population in northern. A case–control study was introduced. We genotyped eight SNPs (rs1800541, rs2070699, and rs5370 in EDN1 gene; rs1801708, rs5333, and rs5335 in EDNRA gene; and rs3818416 and rs5351 in EDNRB gene) and calculated their polymorphic distribution in control group, IS group, and the IS subgroups. In male population, EDN1 gene rs2070699 G allele increased the incidence risk to 1.78 times (P = 0.009; OR 1.78; 95 % CI 1.15–2.75) and the risk of morbidity of rs5370 T allele carrying increased to 1.49 times (P = 0.048; OR 1.49; 95 % CI 1.00–2.21). EDNRA gene mutation rs5335 homozygous CC morbidity risk was significantly lower (P = 0.016; OR 0.52; 95 % CI 0.31–0.88). In the female population, the mutant homozygous AA cancer risk was significantly higher than G allele carriers (P = 0.019; OR 2.65; 95 % CI 1.18–6.00) on EDNRA gene rs1801708. In EDN1 gene, T allele of rs5370 and G allele of rs2070699 may be IS incidence risk factors in Northern Han male population. A allele of rs1801708 in EDNRA gene can increase the risk of IS in Northern Han women population.     

Enterococcus faecalis infection in root canals – host‐derived or exogenous source?

Aims: Enterococcus faecalis is associated with a significant number of refractory endodontic infections. Previous studies report a prevalence of Ent. faecalis ranging from 24% up to 77% in teeth with failed endodontic treatment. The origin of the micro‐organism remains unclear, as enterococci do not belong to the normal oral microflora. The aim of this study was to determine whether these enterococci were of endogenous or exogenous origin. Methods and Results: Fifty consecutive patients with apical periodontitis in need of endodontic orthograde re‐treatment were included. Samples were collected from root canals, saliva and faeces and subjected to microbiological culturing. The genetic relationship between Ent. faecalis from root canals and isolates from the different host sources was determined using pulsed‐field gel electrophoresis. In 16% (8/50) of the patients, enterococci were collected from the root canal samples. The genetic analysis showed that the isolates from the root canals were not related to those from the normal gastrointestinal microflora. None of these patients had enterococci in their saliva samples. Conclusions: Endodontic infections with Ent. faecalis are probably not derived from the patient’s own normal microflora, which indicates that these infections ent. faecalis are of exogenous origin. Significance and Impact of the Study: This is the first study to genetically compare endodontic infectious Ent. faecalis isolates with isolates from the hosts’ own normal microflora.     

机用ProTaper 进行恒磨牙根管预备的临床评价

目的:评价机用ProTaper镍钛根管器械进行恒磨牙根管预备的临床疗效。方法:2007年7月至2010年12月期间就诊的需进行根管治疗的109患者,共计128颗磨牙,包括牙髓炎54颗牙,慢性根尖周炎74颗牙。按随机配对原则分入实验组和对照组,每组64颗牙。实验组用机用ProTaper镍钛根管锉预备根管,对照组用不锈钢K型锉预备根管。两组均采用侧向加压法充填根管,记录每颗患牙的单个根管预备所用时间、根管充填效果、术后不良反应及随访到的远期疗效。结果:机用ProTaper镍钛器械预备单根管所耗时间明显少于对照组,根管预备后疼痛发生率明显低于对照组,根管适充率实验组明显优于对照组,根管治疗术后1年疗效比较也优于对照组。结论:使用机用ProTaper器械进行恒磨牙根管预备快速有效,根充效果好,并发症发生率低,远期疗效确切,值得临床推广。     

高频电对感染根管消毒作用的初步实验研究

目的:初步验证高频电对感染根管是否具有较理想的消毒作用,并且与氢氧化钙药尖的消毒作用进行初步比较分析。方法:本实验制作10只家兔40颗门齿的感染根管动物模型,其中20颗用高频电消毒为实验组。20颗用氢氧化钙药尖消毒为对照组,消毒前后分别作需氧菌和厌氧菌培养并比较其消毒效果。结果:消毒前实验组和对照组各20个根管的需氧及厌氧菌培养全部阳性。实验组消毒后需氧菌3个阳性根管、厌氧菌2个阳性根管,消毒前后对需氧和厌氧菌杀灭作用的差异均具有极显著性(P<0.005)。对照组消毒后需氧菌13个阳性根管消毒作用的差异有显著性(P<0.05)。对照组消毒后厌氧菌11个阳性根管消毒作用的差异有极显著性(P<0.005)。实验组和对照组分别对需氧和厌氧2个菌种之间消毒作用的差异均无显著性(P>0.05)。实验组和对照组对需氧菌的消毒作用和对厌氧菌的消毒作用的组间差异均具有极显著性(P<0.005)。结论:高频电对感染根管内容物的消毒作用优于氢氧化钙药尖,具有临床应用的可行性。值得进一步研究。     

Genetic Variants in C-Reactive Protein and Ischemic Stroke Susceptibility

Considerable discrepancies in the previously reported associations of the C-reactive protein (CRP) gene variants and ischemic stroke (IS) risk prompted us to perform this meta-analysis. We selected the fixed effects Mantel–Haenszel method to estimate the risk of IS [OR (odds ratio) along with its 95 % CI (confidence interval)] in relation to the CRP variants (?717 A > G, 1444 C > T). Heterogeneity test, influence analysis and publication bias test were appropriately performed using respective methods. We analyzed 1,926 IS patients and 2,678 controls and found the ?717 A > G variant was not significantly associated with overall IS risk. Subsequent analysis of the 1444 C > T variant involving 3,278 samples similarly revealed no significant association with IS. There was no substantial heterogeneity or publication bias in this analysis. Our meta-analysis may provide first evidence showing that genetic variants within the CRP locus are unlikely to modulate risk of IS.     

后磨牙模拟根管模型制备与研究

目的:制备后磨牙模拟根管模型。方法:依照预实验中测试的牙本质和树脂根管模型材料的布氏硬度值(牙本质HB72,树脂块HB54)选取纯铜质铜管为材料(纯铜HB58)同时利用预实验中确认的后磨牙模拟根管模型弯曲角度的范围(70°-60°)并参照树脂根管模型相关数据,设计不同弯曲角度(70°,64°,60°)的纯铜质根管模型,将20套镍钛根管锉随机分为4组,其中3组根管锉分别预备相应角度的10个纯铜质后磨牙根管模型,另一组在临床预备10个后磨牙根管作为对照组。所有镍钛根管锉均在疲劳寿命测试装置中测试疲劳寿命。结果:选用根管长度为16mm±1mm,弯曲半径为5mm,内径为0.70mm的纯铜质铜管制作后磨牙根管模型。其中在弯曲角度为70°的后磨牙根管模型中有33%(2/6)近似临床;在弯曲角度为64°的后磨牙根管模型中有67%(4/6)近似临床;在弯曲角度为60°的后磨牙根管模型中有33%(2/6)近似临床。结论:弯曲角度为64°的纯铜制后磨牙模拟根管模型更接近于临床实际,可为体外研究镍钛根管锉各项指标提供一个较为理想的模型。     

后磨牙模拟根管模型制备与研究

目的：制备后磨牙模拟根管模型。方法：依照预实验中测试的牙本质和树脂根管模型材料的布氏硬度值（牙本质HB72,树脂块HB54）选取纯铜质铜管为材料（纯铜HB58）同时利用预实验中确认的后磨牙模拟根管模型弯曲角度的范围（70°-60°）并参照树脂根管模型相关数据,设计不同弯曲角度（70°,64°,60°）的纯铜质根管模型,将20套镍钛根管锉随机分为4组,其中3组根管锉分别预备相应角度的10个纯铜质后磨牙根管模型,另一组在临床预备10个后磨牙根管作为对照组。所有镍钛根管锉均在疲劳寿命测试装置中测试疲劳寿命。结果：选用根管长度为16mm±1mm,弯曲半径为5mm,内径为0.70mm的纯铜质铜管制作后磨牙根管模型。其中在弯曲角度为70°的后磨牙根管模型中有33%（2/6）近似临床;在弯曲角度为64°的后磨牙根管模型中有67%（4/6）近似临床;在弯曲角度为60°的后磨牙根管模型中有33%（2/6）近似临床。结论：弯曲角度为64°的纯铜制后磨牙模拟根管模型更接近于临床实际,可为体外研究镍钛根管锉各项指标提供一个较为理想的模型。     

Frecuencia de Candida en conductos radiculares de dientes con infección endodóntica primaria y persistente

Background

Microbiological identification in endodontic infections has focused mainly on bacteria without giving much attention to yeasts, which, due to their virulence factors, can affect the outcomes of root canal treatment.

Reactive oxygen species generation and antioxidant defense system in hydroponically grown wheat (Triticum aestivum) upon β-pinene exposure: an early time course assessment

We investigated the effect of β-pinene on reactive oxygen species (ROS: lipid peroxidation, membrane integrity, hydrogen peroxide and superoxide ions) generation and activity of antioxidant defense system during early hours of treatment (4, 8, 16 and 24 h) in hydroponically grown Triticum aestivum (wheat). β-Pinene reduced the root and shoot growth of the hydroponically grown wheat. However, the reduction was more pronounced in root length than in shoot length. β-Pinene enhanced ROS generation as indicated by increased levels of malondialdehyde (20–87 %), hydrogen peroxide (9–45 %) and superoxide ion (23–179 %) content, thereby suggesting lipid peroxidation and induction of oxidative stress in a time- and concentration-dependent manner. The oxidative damage was more pronounced at ≥10 µM β-pinene and at ≥8 h after exposure. β-Pinene caused a severe electrolyte leakage from wheat roots indicating membrane disruption and loss of integrity. Enhanced lipid peroxidation and loss of membrane integrity were confirmed by in situ histochemical studies. β-Pinene provoked increase in the activity of lipoxygenase and upregulation in the activities of antioxidant enzymes: catalases, superoxide dismutases, ascorbate peroxidases, guaiacol peroxidases and glutathione reductases. The enhanced activity of lipoxygenases evoked by β-pinene paralleled higher accumulation of MDA, thereby suggesting that antioxidant defense mechanism was not able to prevent β-pinene-induced lipid peroxidation.