双根三根管上颌第一前磨牙根管治疗1例

上颌第一前磨牙三根管的发生率为0.5%~7.5%,目前国内报道的多为三根三根管型,尚未见双根三根管型的病例报告。本病例介绍1例双根三根管型上颌第一前磨牙的根管治疗。     

上颌第一前磨牙根管预备后根管壁厚度的研究

上颌第一前磨牙的牙根解剖形态较复杂 ,多有双分叉根、根面沟和近中凹面[1] 。所以根管预备后 ,根管壁厚度变薄 ,可能出现牙本质壁薄弱 ,甚至根折 ,将影响根管治疗术后修复效果。本实验对上颌第一前磨牙根管预备后 ,根管壁厚度进行测量研究 ,以对根外形有更多的了解。1　材料和方法10 6个上颌第一前磨牙 ,于釉牙骨质界最高点截去牙冠。然后作根管预备 ,根管工作长度距根尖 2ｍｍ[2 ] ,用ＴＲ -ＺＸ电动旋转根管锉预备根管至 # 40 ,用 3 0ｍＬ/Ｌ过氧化氢液和生理盐水交替冲洗 ,吸干 ,氧化锌丁香油糊剂加牙胶尖侧方加压充填根管 ,氧化锌丁香…     

上颌第一前磨牙4根管1例

本文报告1例上颌第一前磨牙三根四根管的发现与诊断过程。通过临床诊断和操作过程中的细致观察和多角度的常规X线牙片,发现并定位了额外根管的存在,并借助锥形束CT和根管显微镜证实三根四根管的存在,最终在手术显微镜下完成了高质量的根管治疗。     

上颌第一前磨牙牙根及根管形态的研究进展

上颌第一前磨牙有复杂的牙根及根管解剖形态,给牙周牙髓治疗和牙体修复治疗带来麻烦和失败.作者通过回顾近年来对上颌第一前磨牙牙根及根管解剖形态的大量系统研究,主要阐述了其牙根及根管解剖特征、根管分型和各根管类型的发生率;并分析了该牙根管治疗的注意点.     

前磨牙根管形态研究进展

前磨牙根管形态较为复杂,根管治疗时容易遗漏根管或根管充填不完全,导致治疗失败。本文回顾以往国内外对于前磨牙根管形态的研究结果,阐述前磨牙根管系统的形态特点及与临床治疗的关系,为临床治疗提供依据。     

上颌第一前磨牙根管的X线研究

根管治疗的成败关键之一,是对根管数目和形态的解剖知识的了解。国外对根管形态有些调查研究,国内此文献报道较少,且大多局限于离体牙的研究。体内根管的X线研究,国内尚未见报道。本文主要通过两种X线摄片方法,对成人上颌第一前磨牙根管进行X线影像观察研究,以期为临床诊断治疗提供参考依据。     

上颌第一前磨牙根管系统研究

目的：制作上颌第一前磨牙离体牙透明标本,研究其根管系统解剖形态。方法：100颗上颌第一前磨牙经透明髓腔处理后,直接在体视显微镜下读取根管系统的形态并作规律性统计处理。结果：①上颌第一前磨牙根管口分为单、双两种类型,②主根管形态以2－2型、1－1型和2－1型常见,③侧副管发生率高,根管侧枝和根尖区的细小分支均高达14％,而且伴随双根管出现的管间交通也高达9％。结论：上颌第一前磨牙的根管治疗效果不确定性较大。     

上颌第一前磨牙根管锥度的研究

目的：研究上颌第一前磨牙的根管锥度。方法：将离体的101个上颌第一前磨牙髓腔作＂颊－舌向＂和＂近－远中向＂X线摄影后输入计算机行图象处理,统计该牙根管全长数值、根管中1／2处颊－舌向直径和近－远中向直径、距根尖端0．5 mm处根管的颊－舌向和近－远中向直径,然后代入公式计算根管的锥度。结果：上颌第一前磨牙根管平均长11．4 mm,根管中段颊－舌径平均宽1．8 mm、近－远中径平均宽0．8 mm,靠近根尖的根管颊－舌径平均宽0．6 mm、近－远中径平均宽0．4 mm;将上述数值代入公式得到该牙根管下段的锥度,在颊－舌象限为0．175,在近－远中象限为0．035。结论：上颌第一前磨牙根管下段并非呈圆锥形空间,而是呈颊－舌径＞近－远中径的扁形腔隙;该牙根管预备之初,选择Profile的I号锉较为适宜。     

上颌第一前磨牙三根管1例

患者男,35岁,因上颌腭侧肿胀疼痛1周来诊。患者半年前进食后患牙疼痛,咬合时加重,当时未做处理。2个月后患者感到腭侧肿胀,自服“甲硝唑”后好转。1周前再次肿胀疼痛难忍来我院就诊。检查:全口牙列完整,牙合面磨耗不均匀,上颌腭侧以14根尖区为中心肿胀隆起,触痛牙周溢脓,14扭转,无龋坏,无折裂,探诊颊侧牙周正常,腭侧牙周袋深7 mm,冷热诊无反应,叩诊( ),Ⅱ度松动,与44、45咬合早接触;X线片示:14扭转,双根,近中牙槽骨呈角形吸收,颊根尖区有低密度透射区。初步诊断:14根尖周炎。处置:14调牙合,开髓,揭髓顶,可见颊腭侧各1个根管口,分别插入诊…     

上颌第二前磨牙S形根管治疗2例

根管形态的变异会增加根管治疗难度,其中S形双弯曲根管一直是根管治疗中的难点,现报道2例上颌第二前磨牙S形根管的根管治疗.     

上颌前磨牙桩道预备后剩余根管壁厚度和抗折强度的研究

目的:探讨上颌前磨牙桩道预备后剩余根管壁厚度及对抗折强度的影响。方法:对100颗单、双根管上颌 前磨牙,用1#～5#P型钻进行桩道预备,用光学显微镜分别测量各组牙冠方和根方剩余根管壁厚度,并观察桩道预 备对抗折强度的影响。结果:单根管上颌前磨牙,1#～2#P型钻预备后,各壁剩余厚度均大于1mm;而对于双根管 上颌前磨牙,1#～3#P型钻预备后,各壁剩余厚度均大于1mm。另外,1#～5#P型钻预备后,牙根抗折强度逐渐变小 (P 0.01),且相同直径器械预备后,双根管抗折强度大于单根管(P 0.01)。结论:用P型钻预备桩道时,单根 管牙最大可用2#P型钻预备,双根管牙最大可用3#P型钻预备,且剩余牙质的量与牙齿的抗折强度成正相关。     

The Effect of Different Cavity Designs and Temporary Filling Materials on the Fracture Resistance of Upper Premolars

IntroductionThe aim of this study was to compare the fracture resistance of upper premolars undergoing root canal treatment that had been temporarily restored with 4 different temporary filling materials.MethodsThis study was based on 120 extracted upper premolars. Eight teeth were left intact and served as the negative control group. Mesio-occluso-distal cavities with 2 different designs were prepared for the rest of the teeth (for group 1 a width of one third of the intercuspal distance and for group 2 a width of two thirds of the intercuspal distance). Then, the endodontic access cavities were prepared, and the root canals instrumented with Revo-S rotary files (MicroMega, Besancon, France). Thereafter, a total of 16 teeth consisting of 8 each from group 1 and group 2 served as the positive control group and did not have any temporary filling material. The teeth were randomly divided into 4 subgroups (n = 12) according to the temporary filling material: Cavit G (3M ESPE, St Paul, MN), Coltosol F (Coltène/Whaledent AG, Altstätten, Switzerland), Intermediate Restorative Material (Dentsply Sirona, Konstanz, Germany), or DiaTemp (DiaDent Europe BV, Almere, Netherlands). Each specimen was then subjected to a fracture resistance test using a universal testing machine until the fracture occurred. The force required to fracture each specimen was recorded, and the data were statistically analyzed.ResultsThe negative control group showed the highest fracture resistance values compared with the other groups, whereas the positive control groups showed the lowest fracture resistance values. There were no statistically significant differences in the fracture resistance of upper premolar teeth undergoing root canal treatment among Cavit G, Intermediate Restorative Material, Coltosol F, and DiaTemp, regardless of the cavity width (P > .05).ConclusionsThe cavity design was found to be an effective factor on the fracture resistance of upper premolar teeth undergoing root canal treatment. The temporary filling materials tested did not affect the fracture resistance.     

Survival Rates from Fracture of Endodontically Treated Premolars Restored with Full-coverage Crowns or Direct Resin Composite Restorations: A Retrospective Study

Introduction

The aim of the present study was to compare the survival rates against fracture of premolar endodontically treated teeth (ETT) restored with resin composite or crowns and to identify risk factors associated with the fracture.

Fracture resistance and failure modes of polymer infiltrated ceramic endocrown restorations with variations in margin design and occlusal thickness

Purpose

The purpose of this in vitro study was to assess the effect of varying the margin designs and the occlusal thicknesses on the fracture resistance and mode of failures of endodontically treated teeth restored with polymer infiltrated ceramic endocrown restorations.

Effect of Fiber Post and Cusp Coverage on Fracture Resistance of Endodontically Treated Maxillary Premolars Directly Restored with Composite Resin

IntroductionThere are different reinforcement methods in restoring root-filled teeth. The aim of this in vitro study was to evaluate the effect of fiber post and cusp coverage on fracture resistance of endodontically treated maxillary premolars directly restored with composite resin.MethodsSeventy-five maxillary premolars were divided into 5 groups (n = 15). Except for the control group (intact teeth), in other groups mesio-occlusodistal (MOD) cavities were prepared after endodontic treatment. In the groups with cusp coverage, both buccal and lingual cusps were reduced up to 2 mm. Then specimens in the experimental groups were prepared as follows: composite resin restoration without post and cusp capping, composite resin restoration without post but with cusp capping, composite resin restoration with post but without cusp capping, and composite resin restoration with post and cusp capping. After finishing and polishing, the specimens were stored in distilled water at 37°C for a week. Subsequent to thermocycling and exertion of compressive forces parallel to the long axes of the teeth at a strain rate of 2 mm/min, data were analyzed by using one-way analysis of variance and χ² test.ResultsThere were no significant differences in fracture resistance between the groups (P = .057). However, χ² test showed statistically significant differences between the groups in failure mode (P < .001). The highest number of favorable fractures was observed in the control group (intact teeth).ConclusionsRoot-filled maxillary premolars, restored with direct resin composite with or without fiber post and cusp capping, had similar fracture resistance under static loading.     

Resin Composite Core and Fiber Post Improved the Fracture Parameters of Endodontically Treated Maxillary Premolars with Wedge-shaped Cervical Lesions

IntroductionThe aim of this study was to evaluate the fracture resistance and fracture patterns of endodontically treated maxillary premolars with wedge-shaped cervical lesions restored with a resin composite core with or without a fiber post under nonaxial loading.MethodsSixty extracted human maxillary premolars with 2 root canals were randomly allocated into 4 groups (n = 15). Forty-five teeth were prepared with a wedge-shaped lesion at the buccal cervical area and root canal treatment. There were 3 restoration groups: no restoration, restoration with a resin composite core, and restoration with a resin composite core and a fiber post. Intact teeth served as the control group. All teeth were subjected to thermocycling and cyclic loading. A 45° compressive load was applied to the palatal plane of the buccal cusp until tooth fracture. The fracture resistance and facture patterns were analyzed using 1-way analysis of variance and the chi-square test (α = 0.05), respectively.ResultsThe no restoration group demonstrated the lowest fracture resistance and was significantly different from the other groups (P < .001). The intact teeth presented the highest fracture resistance, which was not significantly different from the restoration with a resin composite core and a fiber post group (P > .05). The failure patterns were significantly different between groups (P < .001). Most intact teeth fractured coronally to the cementoenamel junction level, whereas most teeth in the other groups fractured at the gingival margin of the cervical lesion.ConclusionsEndodontically treated maxillary premolars with wedge-shaped cervical lesions restored with fiber posts and a resin composite cores had a fracture resistance equivalent to intact teeth. However, their fracture patterns were not improved by the fiber post and a resin composite core.