Endodontic Outcomes in Mandibular Second Premolars with Complex Apical Branching

Introduction

Mandibular premolars that have rare and complex anatomies may have the highest failure rate in nonsurgical endodontic treatment. Awareness of rare and complex anatomies of mandibular second premolars would aid in better outcomes of the treatment. This study aimed to evaluate the success of nonsurgical root canal treatment of mandibular second premolar teeth with complex apical branching.

Radicular Groove Accessory Canal Morphology in Mandibular First Premolars: Micro–computed Tomographic Study

Introduction

The purpose of this study was to investigate the morphologic features of radicular groove accessory canals (RGACs) in mandibular first premolars and their relationship to root anatomy by micro–computed tomographic imaging.

Relationship of the Incidence of C-shaped Root Canal Configurations of Mandibular First Premolars with Distolingual Roots in Mandibular First Molars in a Taiwanese Population: A Cone-beam Computed Tomographic Study

Introduction

The aim of this study was to determine the prevalence of C-shaped canal configurations (CSs) and radicular grooves (RGs) in permanent mandibular first premolars (MPs) and to investigate the relevance of such complexities with the presence of distolingual roots (DLRs) in permanent mandibular first molars (MMs).

Root Canal Morphology of South Asian Indian Mandibular Premolar Teeth

Introduction

The purpose of this study was to study the root canal morphology of South Asian Indian mandibular premolars using a tooth clearing technique.

Methods

Two hundred mandibular premolar teeth were collected from different dental schools and clinics in India. After pulp tissue removal and root canal staining with Indian ink, the specimens were decalcified with 5% nitric acid, dehydrated in ethyl alcohol, and subsequently cleared in methyl salicylate.

Results

Of the 200 mandibular premolars, 100 were first premolars and 100 were second premolars. Of the first premolars, 94% had a single root, whereas 6% were 2 rooted. Seventy-six percent had a single canal, 22% had 2 canals, and 2% had 3 canals. Eighty-two percent had a single apical foramen, 16% had 2 foramens, and 2% teeth had 3 apical foramens. Eighty percent of teeth had type I, 6% had type II, 10% had type IV, 2% had type V, and 2% teeth had type IX root canal anatomy. Of the 100 second premolars, 92% had a single root, whereas 8% teeth were 2 rooted and fused. Fifty-eight percent of teeth had a single canal, and 42% had two canals. Eighty-eight percent had a single apical foramen, and 12% had 2 foramens. Sixty-six percent had type I, 30% had type II, and 4% had type V root canal anatomy.

Conclusions

A high prevalence of 2 canals was noted in the first and second premolars. Also, 20% of first premolars and 34% of second premolars had a root canal anatomy other than type I.     

牙周牙髓联合病变伴畸形根面沟治疗的临床疗效研究

目的:评价显微根管外科手术联合牙周治疗牙周牙髓联合病变伴畸形根面沟的治疗效果。方法:选择畸形根面沟致牙周牙髓联合病变的患牙11例,经显微根管治疗后,采用显微根管外科手术联合牙周治疗,分别记录患牙术前、术后6个月及术后1年牙周探诊深度(PD)、龈沟出血指数(SBI)、牙齿松动度(TM),并进行统计分析。所有患牙术后6个月及1年复查,通过临床检查和X线片评定根尖周病损愈合结果。结果:术后6月及术后1年分别与术前相比,PD、SBI及TM均明显降低(P<0.05);术后6月成功率为81.82%;术后1年成功率为90.91%。结论:显微根管外科手术联合牙周治疗是畸形根面沟致牙周牙髓联合病变的可行治疗方法。     

Finding appropriate nickel-titanium instruments for lingual canals in mandibular first premolars with two canals: A micro-CT study

This study aimed to find appropriate nickel-titanium instruments for lingual canals in mandibular first premolars with two canals. Forty-two extracted mandibular first premolars with lingual canals (Vertucci type V) verified by micro-CT scanning were selected. The teeth were randomly divided into three groups, and their lingual canals were instrumented by M3, HyFlex CM and XP-endo Shaper, respectively. After instrumentation, the canal morphology was scanned again by micro-CT. The canal morphologies of pre- and post-instrumentation were reconstructed and aligned. Morphological changes of the lingual canals were evaluated. No instrument breakages occurred during the procedure of root canal instrumentation. HyFlex CM and XP-endo Shaper performed better than M3 files in preparation of lingual canals (Vertucci type V) of mandibular first premolars in terms of apical transportation and unprepared surface area.     

离体下颌前磨牙根管的颊舌向弯曲

目的：确定人下颌第一、二前磨牙的颊舌向根管弯曲程度和情况。方法：离体第一前磨牙69个，第二前磨牙93个，摄近中远中向的X线片，用Photoshop5．0软件分析根管，用Weine氏法测量根管的弯曲度，测量角度大于18度时，则认为根管存在明显的弯曲，根管的构型采用Vertucci分类法。结果：下颌第一前磨牙根管颊舌向弯曲牙齿的发生率是7.2％（5／69），下颌第二前磨牙根管颊舌向弯曲牙齿的发生率是5．3％（5／93），二者之间无明显的差异（P〉0．05）。结论：下颌前磨牙颊舌向的根管弯曲发生率较低。     

Morphologic Micro–Computed Tomography Analysis of Mandibular Premolars with Three Root Canals

Introduction

This study aimed to describe the anatomy of mandibular premolars with type IX canal configuration by using micro–computed tomography.

Methods

Mandibular premolars with radicular grooves (n = 105) were scanned, and 16 teeth with type IX configuration were selected. Number and location of canals, distances between anatomic landmarks, occurrence of apical delta, root canal fusion, and furcation canals, as well as 2-dimensional (area, perimeter, roundness, major and minor diameters) and 3-dimensional (volume, surface area, and structure model index) analysis were performed. Data were statistically compared by using analysis of variance and Kruskal-Wallis tests (α = 0.05).

Results

Overall, specimens had 1 root with a main canal that divided into mesiobuccal, distobuccal, and lingual canals at the furcation level. Mean length of the teeth was 22.9 ± 2.06 mm, and the configuration of the pulp chamber was mostly triangle-shaped. Mean distances from the furcation to the apex and cementoenamel junction were 9.14 ± 2.07 and 5.59 ± 2.19 mm, respectively. Apical delta, root canal fusion, and furcation canals were present in 4, 5, and 10 specimens, respectively. No statistical differences were found in the 2-dimensional and 3-dimensional analyses between root canals (P > .05).

Conclusions

Type IX configuration of the root canal system was found in 16 of 105 mandibular premolars with radicular grooves. Most of the specimens had a triangle-shaped pulp chamber. Within this anatomic configuration, complexities of the root canal systems such as the presence of furcation canals, fusion of canals, oval-shaped canals in the apical third, small orifices at the pulp chamber level, and apical delta were also observed.     

Vertical Root Fracture in Buccal Roots of Bifurcated Maxillary Premolars from Condensation of Gutta-percha

Introduction

Maxillary premolars are among the teeth most susceptible to vertical root fracture (VRF) from lateral condensation of gutta-percha. These teeth are distinguished by a complex anatomy of the buccal root including a large depression in the dentin wall facing the bifurcation. It is hypothesized that tooth sectioning coupled with 2-dimensional fracture analysis is instrumental in understanding VRF in such teeth. VRF was examined by tooth sectioning following the development of a fracture mechanics analysis to predict VRF in such roots.

Root form and canal morphology of mandibular premolars in a Jordanian population

AIM: To investigate the root canal anatomy of mandibular premolars in a Jordanian population. METHODOLOGY: Nine hundred extracted mandibular premolars were examined. After the length of the teeth was measured, the presence of developmental grooves and furcated roots was noted. Following the preparation of access cavities, pulp tissue was removed and the canal systems were stained. The teeth were then rendered clear by demineralization and immersion in methyl salicylate. Cleared teeth were examined and the following features were evaluated: (i) type of root canals; (ii) presence and location of lateral canals; transverse anastomosis; (iii) location of apical foramina; and (iv) frequency of apical deltas. RESULTS: The mean lengths of first and second mandibular premolars were 22.6 mm (18-27.5 mm) and 22.2 mm (16-26.5 mm), respectively. Although the majority of the specimens corresponded to Vertucci's classification scheme, analysis of this large data set revealed four additional root canal morphologies. Variable root canal morphologies were found in the mandibular first premolars; two separate apical foramina were found in 33% of the teeth with two canals, compared to 6.2% with one apical foramen. Teeth with three separate apical foramina were scarce (2.2%). The majority of the mandibular second premolars had a single canal; 72% of teeth possessed type I canal systems, whilst 22.8% of the roots had two canals with two separate apical foramina. CONCLUSIONS: The prevalence of multiple canals in the investigated Jordanian mandibular premolars was high, especially for the second mandibular premolar, in comparison with previous studies performed on populations of different racial origin.     

Diagnostics and Treatment of Palatal Radicular Grooves

The palatal radicular groove represents a de-velopmental anomaly that mainly affects the maxil-lary incisor teeth. Although palatal radicular groo-ves can give rise to severe periodontal attachmentloss, endodontic lesions, and premature tooth loss,this anomaly has not attracted much attentionfrom the dental community. The following articlegives a short review on the etiology, diagnostics,treatment and prognosis of palatal radicular groo-ves. Furthermore, a short case report of a patienttreated…     

Complicated Root Canal Morphology of Mandibular Lateral Incisors Is Associated with the Presence of Distolingual Root in Mandibular First Molars: A Cone-beam Computed Tomographic Study in a Taiwanese Population

Introduction

The aim of this study was to assess the root canal configurations in permanent mandibular lateral incisors (PMLIs) and the correlation between the root canal configurations of PMLIs with the appearance of a distolingual root (DLR) in permanent mandibular first molars (PMFMs) using cone-beam computed tomographic (CBCT) imaging.

The Presence of Distolingual Root in Mandibular First Molars Is Correlated with Complicated Root Canal Morphology of Mandibular Central Incisors: A Cone-beam Computed Tomographic Study in a Taiwanese Population

Introduction

The aim of this study was to assess the prevalence of complicated root canals in permanent mandibular central incisors (PMCIs) and its correlation with the presence of a distolingual root (DLR) in permanent mandibular first molars (PMFMs) using cone-beam computed tomographic imaging in a Taiwanese population.

下颌恒切牙根管解剖因素与根管治疗难度的相关分析

目的 分析下颌恒切牙根管解剖因素对根管治疗难度的影响。方法 选择299颗牙体完整的离体中国人下颌恒切牙为研究对象,测量其根管解剖指标包括根管长度、根管数量及形态、根管弯曲度以及髓腔与根管钙化程度,按照四川大学华西口腔医院牙体牙髓科制定的根管治疗难度系数临床评估标准及美国牙髓病学会推荐的牙髓病例难度评估方法评估该牙根管治疗难度,并采用Logistic回归分析,观察以上各指标与根管治疗难度的相关关系。结果 下颌恒切牙根管治疗难度为Ⅰ级、Ⅱ级、Ⅲ级者分别占29.4%、20.1%和50.5%。根管治疗难度与根管长度、数目、钙化程度以及弯曲度存在明显的相关性（P<0.005）。结论 下颌恒切牙根管治疗难度与根管解剖密切相关,根管治疗难度较大。     

Root canal treatment of three-rooted maxillary first and second premolars--a case report

AIM: To report the diagnosis and successful clinical management of a patient with anatomical variation in maxillary first and second premolars. SUMMARY: Maxillary premolars have a highly variable root canal morphology, but it is rare, especially in the second premolar, to find three canals. This article describes the diagnosis and clinical management of first and second premolars with three canals and three separate roots, drawing particular attention to radiographic interpretation and access refinements. KEY LEARNING POINTS: Clinicians should be aware of anatomical variations in maxillary premolars and be able to apply this knowledge in radiographic and clinical interpretation. Access cavity refinements may be required for stress-free entry to complex anatomy. Complex premolar anatomy may be predictably managed following its identification and negotiation.     

A cone-beam computed tomography study of root canal morphology of maxillary and mandibular premolars in a Turkish population

Aim. The aim of this study was to evaluate the root canal number and configuration of maxillary and mandibular premolar teeth by gender, intervals for decades, tooth position and unilateral or bilateral occurrence in a Turkish population using Cone Beam Computed Tomography(CBCT) scanning. Methodology. CBCT images of 5496 maxillary and mandibular premolars from 849 patients were evaluated. The following was evaluated in all the images: numbers of roots and root canals, the morphology of the root canal configuration according to the Vertucci classification, male–female differences in the tooth position and male–female differences in unilateral or bilateral occurrence. The reliability data were analyzed with a chi-square test. Results. The most prevalent root canal frequency was the two canals (86.2%) and type IV (76.9%) configuration for maxillary first premolar, one canal (59.7%) and type I (54.5%) canal configuration for second premolar. The incidence of one canal was higher in females and the occurrence of two or three canals was more common in males. The incidence of one canal was higher on the left side of maxillary premolars and the incidence of two canals was higher on the right side. Most mandibular first (93.5%) and second (98.5%) premolars had one canal. In general, females had one root canal of the mandibular premolar, whereas males had two or three canals. The type I configuration was most common and the incidence was higher on the right side. There were some differences found in the frequency distribution of the number of root canals and configuration of maxillary and mandibular premolar teeth according to intervals for decades. Conclusion. CBCT scanning provides comprehensive information about the root canal morphology of maxillary and mandibular premolar teeth. These data may help clinicians in root canal treatment of premolar teeth.     

Rare Root Canal Configuration of Mandibular Second Premolar Using Cone-beam Computed Tomographic Scanning

The aim of this case report was to demonstrate how the use of cone-beam computed tomographic (CBCT) imagery is beneficial when treating a tooth with an unusual anatomic variation. A 43-year-old female patient presented to our private practice after a referral from her general dentist. Endodontic therapy was previously initiated and unable to be completed because of suspicious anatomic anatomy. CBCT imagery confirmed the presence of a C-shaped root configuration and 3 canals within the tooth. Root canal treatment was completed successfully without complications. The use of CBCT imaging was valuable in determining the root morphology and rare canal anatomy to enhance treatment and success.     

Use of Cone-beam Computed Tomography to Evaluate Root Canal Morphology and Locate Root Canal Orifices of Maxillary Second Premolars in a Chinese Subpopulation

Introduction

The aim of this study was to investigate root canal morphology and locate root canal orifices of maxillary second premolars in a Chinese subpopulation using cone-beam computed tomographic imaging.

Methods

A total of 392 cone-beam computed tomographic images of maxillary second premolars were obtained from 238 patients who required a preoperative assessment for implant surgery or orthodontic treatment. The number of roots and root canals and root canal configuration were investigated and categorized using Vertucci's criteria. The distance between the root canal orifice and the anatomic apex and the distance between root canal orifices in those teeth with 2 root canals were measured and evaluated. The Fisher exact test was used to analyze the correlation between the number of roots and sex.

Results

Among the 392 teeth, 86.5% (n = 339) had 1 root; 45.4% (n = 178) of the teeth had 1 root canal, and 54.3% (n = 213) had 2 root canals that ranged from type II–type V. The majority of teeth with 2 root canals showed a type IV canal configuration (n = 79, 20.2%) followed by type II (n = 64, 16.3%), type III (n = 45, 11.4%), and type V (n = 25, 6.4%). Only 1 tooth had 3 root canals. No significant difference was found between the number of roots and sex (P > .05). Among the 213 teeth with 2 root canals, the most frequent distribution of the distance between the root canal orifice and the anatomic apex was 5–10 mm (n = 157). The distance between the 2 orifices of 189 teeth was 1–4 mm.

Conclusions

The frequency of teeth with 2 root canals was high in maxillary second premolars. The internal morphology of teeth with 2 root canals was variable. This study provided useful information about the root canal morphology of maxillary second premolars in a Chinese subpopulation.     

Clinically Relevant Dimensions of 3-rooted Maxillary Premolars Obtained Via High-resolution Computed Tomography

Introduction

This study aimed to characterize the dimensions of a selection of 3-rooted maxillary premolars through high-resolution computed tomographic analysis considering measures of clinical interest for root canal treatment, such as root wall thickness, canal diameters, and distances between 2 canals in fused roots and between the root apex and foramen.

Methods

Fifteen 3-rooted human maxillary premolars extracted for therapeutic reasons were individually scanned using a high-resolution desktop high-resolution computed tomographic system. Starting from the apical foramen, the selected cross-sectional images corresponding to each millimeter of the roots were evaluated. Measures of clinical interest were determined using Image J software (version 1.41; National Institutes of Health, Bethesda, MD).

Results

Root wall thickness as thin as 0.4 and 0.6 mm was detected in the apical portion of buccal and palatal roots, respectively. In the cervical portion, buccal roots had narrower root walls (0.817–1.670 mm) compared with palatal roots (1.361–2.720 mm). In all thirds, the palatal canal was wider compared with the mesiobuccal and distobuccal canals. In the buccopalatal direction, all roots had thicker root walls toward the furcation, whereas in the mesiodistal direction the mesiobuccal and distobuccal roots had the thinnest walls along their distal and mesial aspects, respectively. Both buccal canals revealed dentin apposition 2 mm from the canal orifice, resulting in cervical constriction. Generally, the distance between the root apex and the foramen was greater in distobuccal roots in comparison with the others with a tendency for foramina to be eccentric.

Conclusions

Three-rooted premolars are a clinical challenge not just because of their low frequency and difficulties regarding diagnosis and root canals access but also because of their fragile roots. These phenomena are critical in terms of the amount of dentin removed during the preparation of root canals and during post space preparation.     

Mandibular molar with merging mesiobuccal and distal root canals

Abstract A lower 2nd molar with an anomalous root canal anatomy is described. The floor of the pulp chamber showed the usual anatomic configuration with 2 mesial and 1 distal canal orifices. The mesiolingual canal had a normal course. However, the mesiobuccal and the distal canals merged to form 1 single canal in the apical 3 mm of the root.