Apical Deltas Research Articles

Internal and external morphology of mandibular molars: An original micro‐CT study and meta‐analysis with review of implications for endodontic therapy

The aim of this radiological micro-CT study and meta-analysis was to determine the morphological features of the root canal anatomy of the mandibular molars. The radiological study included micro-CT scans of 108 mandibular first, 120 mandibular second, and 146 mandibular third molars. For our meta-analysis, an extensive search was conducted through PubMed, Embase, and Web of Science to identify articles eligible for inclusion. Data extracted included investigative method (cadaveric, intraoperative, or imaging), Vertucci type of canal configuration, presence/number of canals, roots, apical foramina, apical deltas, and intercanal communications. In the mesial roots of mandibular molars, the most frequent Vertucci type of canal configuration was type IV, except for the mandibular third molar where type I was most common. Type I was most common in the distal root. There were usually two canals in the mesial root and one in the distal root. Two was the most common number of roots, and a third root was most prevalent in Asia. One apical foramen was most common in the distal root and two apical foramina in the mesial root. Intercanal communications were most frequent in the mesial root. Knowledge of the complex anatomy of the mandibular molars can make root canal therapy more likely to succeed. We recommend the use of cone-beam computed tomography before and after endodontic treatment to enable the root anatomy to be accurately described and properly diagnosed, and treatment outcome to be assessed. Clin. Anat. 31:797-811, 2018. © 2018 Wiley Periodicals, Inc.

Utilizing the GentleWave® System for Debridement of Undetected Apical Anatomy

Debriding and disinfecting complex anatomies within the root canal system pose a major challenge during root canal therapy. Even with current chemomechanical techniques, debris and bacterial remnants are commonly left behind, which are generally believed to increase the risk of endodontic failure. This case details the use of a new technique to debride complex apical anatomy in a maxillary molar. A 48-year-old female presented to the clinic with a chief complaint of increasing pain in her tooth. Clinical examination of the right first maxillary molar (#3) revealed moderate sensitivity to percussion and mild sensitivity to palpation. A pulpal diagnosis of symptomatic irreversible pulpitis and a periapi-cal diagnosis of symptomatic apical periodontitis were made. Mechanical instrumentation was performed using rotary file size #25/.04 for the mesiobuccal and distobuccal canals and size #25/.06 for the palatal canal to create a fluid path and enable obturation of the root canal system following the GentleWave® Procedure. The GentleWave Procedure was completed using Multisonic Ultracleaning™ for complete debridement and disinfection of the root canal system. The tooth was obturated using a warm vertical continuous wave obturation technique. Postoperative radiographs revealed complex anatomy within the apical third that was undetected both during pre-operative radiography and mechanical instrumentation. The palatal canal exhibited a complex apical delta with multiple points of exit, and the mesiobuccal canal revealed an undetected lateral canal within the apical third that had a separate and distinct egress. Conclusion and clinical significance: It is important for the clinician to debride and disinfect complex anatomy within the root canal system to reduce the risk of endodontic failure. This case report highlights the clinical significance of utilizing the GentleWave Procedure for detecting complex apical anatomy during endodontic therapy.

Micro-CT Evaluation of Root and Canal Morphology of Mandibular First Premolars with Radicular Grooves.

The aim of this study was to evaluate morphological features of 70 single-rooted mandibular first premolars with radicular grooves (RG) using micro-CT technology. Teeth were scanned and evaluated regarding the morphology of the roots and root canals as well as length, depth and percentage frequency location of the RG. Volume, surface area and Structure Model Index (SMI) of the canals were measured for the full root length. Two-dimensional parameters and frequency of canal orifices were evaluated at 1, 2, and 3 mm levels from the apical foramen. The number of accessory canals, the dentinal thickness, and cross-sectional appearance of the canal at different root levels were also recorded. Expression of deep grooves was observed in 21.42% of the sample. Mean lengths of root and RG were 13.43 mm and 8.5 mm, respectively, while depth of the RG ranged from 0.75 to 1.13 mm. Mean canal volume, surface area and SMI were 10.78 mm3, 58.51 mm2, and 2.84, respectively. Apical delta was present in 4.35% of the sample and accessory canals were observed mostly at the middle and apical thirds. Two-dimensional parameters indicated an oval-shaped cross-sectional appearance of the root canal with a high percentage frequency of canal divisions (87.15%). Canal configuration type V (58.57%) was the most prevalent. C-shaped configuration was observed in 13 premolars (18.57%), whereas dentinal thickness ranged from 1.0 to 1.31 mm. Radicular grooves in mandibular first premolars was associated with the occurrence of several anatomical complexities, including C-shaped canals and divisions of the main root canal.

A new system for classifying accessory canal morphology.

Thorough knowledge of anatomical complexities of the root canal system has a direct impact on the effectiveness of canal preparation and filling, and is an essential prerequisite for successful root canal treatment. A wide range of complex variations in root canal anatomy exists, including root canal configuration type, developmental anomalies and minor canal morphology such as accessory canals and apical deltas. Accessory canals and apical deltas have been associated with pulp disease, primary canal infection, canal reinfection and post-treatment disease. The current definitions of accessory canal anatomy are not standardized and potentially confusing. Given their role in endodontic disease and their impact on treatment outcomes, there is a need to have a simple classification of their anatomy to provide an accurate description of their position and path from the canal to the external surface of the root. The purpose of this article is to introduce a new system for classifying accessory canal morphology for use in research, clinical practice and training.

Morphological evaluation of maxillary second molars with fused roots: a micro-CT study.

To evaluate the internal and external morphologies of fused-rooted maxillary second molars by means of micro-computed tomography (micro-CT) analysis. A total of 100 fused-rooted maxillary second molars from a Brazilian subpopulation were divided into six groups according to the root morphology. The samples were scanned at a resolution of 19.6μm and evaluated with regard to the external morphology of the roots, the root canal configuration, the percentage frequency of C-shaped canals and isthmuses, as well as the morphology of the root canal system at 1, 2 and 3mm from the anatomical apex of the fused roots. The most prevalent root canal fusions were type 1, mesiobuccal root fused with distobuccal root (32%), followed by type 3, DB root fused with P root (27%), and type 4, MB root fused with DB root, and P root fused with MB or DB roots (21%). The prevalence of C-shaped root canal systems were 22%. Depending on the type of root fusion, the percentage frequency of isthmuses in the apical level varied from 9.3% to 42.8%, whilst the presence of apical deltas ranged from 18.5% to 57.1% of teeth. The root canal system of maxillary second molars with fused roots may have a high incidence of merging canals, isthmuses, apical deltas and C-shaped configurations.

Mandibular Birinci Molar Dişlerin Mezial Köklerindeki Apikal Delta Morfolojisinin Kantitatif İncelenmesi: Bir Mikro-BT Çalışması

Objective: The apical delta is the branching of the main root canal dividing into three or more ramifications near the root apex, while the main canal itself becoming indistinguishable. Aim of this study was to analyze apical delta morphologies of mesial root canals of mandibular first molar teeth quantitatively using micro-computed tomography (micro-CT). Material and Methods: Two hundred and sixty-nine mesial roots of mandibular first molar teeth were scanned by micro-CT. Following the initial scanning, 22 specimens showing apical delta ramifications were selected from reconstructed micro-CT images. The numbers and vertical extension of the apical ramifications were recorded. For each specimen, major diameter, minor diameter and roundness values at the most apical slices of the apical delta ramifications and at the slice where ramifications merged to form to main canal were calculated. Data were analyzed using descriptive statistics. Results: The incidence of apical delta was 13.01%. A total of 96 apical delta ramifications were quantitatively analyzed. The mean number of apical delta ramifications was 4.45 per specimen and the mean vertical extension was 0.95 mm. Majority of the apical delta ramifications exhibited noncircular cross sectional shape. Conclusion: The occurrence of apical delta is not uncommon in clinical practice. The shape, number and the height of the apical delta are variable. These complex morphological properties of apical delta might complicate three-dimensional shaping and obturation of root canal systems.

Complex Apical Anatomy Revealed Following Endodontic Treatment of a Maxillary Molar Using the GentleWave System: A Case Report

Introduction: Primary root canal treatment success depends on a number of variables, including debridement and disinfection of the root canal system to remove all bacteria and diseased pulpal and dentinal tissues. Complex root canal anatomy, such as concealed isthmuses, apical deltas and lateral canals, hinder this objective, making instrumentation of these regions nearly impossible. Recent advancements within the endodontic space have focused on improved cleaning and disinfection techniques that will enhance cleaning and debridement, even in difficult to navigate anatomy within the apical third. Background: This case study explores the effectiveness of the GentleWave® Procedure in treating a maxillary second molar diagnosed with irreversible pulpitis and symptomatic apical periodontitis that also featured complex apical root canal anatomy that was undetected until obturation was completed. Methods: A minimally invasive endodontic protocol was utilized to maximize preservation of tooth structure. The tooth was conservatively accessed followed by minimal instrumentation to a size 25/04 for creation of a fluid path and to facilitate future placement of root canal obturation material. Multisonic Ultracleaning™ and debridement were accomplished with the GentleWave Procedure. After obturation with gutta-percha and sealer, a final radiograph revealed a clinically significant obturation with previously unseen lateral canals and an isthmus within the apical third. Results: The previously diagnosed symptomatic apical periodontitis had fully resolved by the three-week followup visit. This case report demonstrates a viable minimally invasive endodontic treatment for uncovering root canal systems with complex apical anatomy utilizing the GentleWave Procedure.

Root canal morphology of mandibular first premolars in Saudi Arabian southern region subpopulation

Introduction: The aim of this study was to investigate the root canal morphology of Saudi Arabian mandibular first premolars by tooth clearing technique. Materials and Methods: One-hundred mandibular first premolars were collected from different dental schools and primary health care centers of the southern region of Saudi Arabia. Access cavities were prepared, the pulp tissue was dissolved, and teeth were subjected to clearing technique protocol. The transparent teeth were examined under dental microscope and following features were analyzed: number of roots, number of root canals, number of apical foramina, root canal configuration (Vertucci's classification), number of lateral canals, and intercanal communications. Results: Of the 100 mandibular first premolars, 80% had a single root, 18% had two roots, whereas 2% were three rooted. Seventy-two percent had a single canal, 26% had two canals, and 2% teeth had three canals. Seventy-three percent had a single apical foramen, 19% had two foramens, 2% had three apical foramens, and 6% had multiple apical foramina (apical delta). Sixty-nine percent had Type I, 8% had Type III, 4% had Type IV, 16% had Type V, 2% had Type IX, and 1% had an additional root canal configuration. Lateral canals were found in 38% and intercanal communications in 16% teeth. Conclusions: Although the majority of the study samples had a single root and one root canal, two roots were found in 18% and two canals in 26%. Such morphological variations should be taken into consideration to ensure successful root canal treatment of these teeth.

Micro-CT evaluation of apical delta morphologies in human teeth.

The apical delta is an intricate system within the root canal and incompletely debridement may affect the long-term prognosis of root canal therapy. The aim of the present study is to investigate the morphologic features of apical deltas in human teeth with micro-computed tomography (micro-CT) using a centreline-fitting algorithm. One hundred and thirty-six apical deltas were detected in 1400 teeth. Molars had more apical deltas (15.8%) than anterior teeth (6.3%). In maxillary molars, the mesiobuccal root had a significantly higher prevalence of apical delta than the palatal root or the distobuccal root. The median vertical distance of the apical delta was 1.87 mm with 13% more than 3 mm. The median diameter and length of the apical delta branches were 132.3 and 934.5 μm. Apical delta branches were not straight with cross-sectional shapes being non-circular. These morphological features of apical delta may complicate debridement of the infected root canal system.

A Micro-Computed Tomography Study of the Root Canal Morphology of Mandibular First Premolars in an Emirati Population

Objective: To investigate variations in the root canal morphology of mandibular first premolars in a population from the United Arab Emirates using micro-computed tomography (micro-CT) and conventional radiography. Materials and Methods: Three-dimensional images of 50 extracted human mandibular first premolars were produced using a micro-CT scanner, and conventional radiography was also used to record the number of roots, the root canal system configuration, the presence of a C-shaped canal system and lateral canals, intercanal communications, and the number and location of apical foramina. The interpretations of micro-CT and conventional radiography were statistically analyzed using Fisher's exact test. Results: Variable root canal configurations based on Vertucci's classification were observed in the teeth (i.e., types I, III, IV, V, and VII). The examined teeth exhibited the following 2 additional root canal configurations, which did not fit Vertucci's classification: type 1-2-3 and type 1-3. A C-shaped canal configuration was present in 14 (28%) cases, and lateral canals were present in 22 (44%) cases. Apical deltas were found in 25 (50%) cases, intercanal communications were seen in 6 (12%) cases, and apical loops were seen in 2 (4%) of the samples. Micro-CT and X-ray imaging identified 39 (78%) and 34 (68%) apical foramina, respectively. A single apical foramen was detected in 33 (66%) samples, and 2 or 3 apical foramina were detected in 14 (28 %) and 3 (6%) samples, respectively. In 18.5 (37%) samples the apical foramina were located centrally, and in 31 (62%) they were located laterally. Conclusion: A complex morphology of the mandibular first premolars was observed with a high prevalence of multiple root canal systems.

Evaluation of root canal morphology of maxillary second premolars in a Saudi Arabian sub-population: An in vitro microcomputed tomography study.

AimTo investigate the root canal morphology of maxillary second premolars in a Saudi Arabian subpopulation using microcomputed tomography (micro-CT).MethodologyMicro-CT analysis was performed on 100 maxillary second premolars. The anatomy of each tooth (number of roots, canals, orifices, and apical foramina, and the presence of apical deltas and accessory canals) was analyzed from reconstructed three-dimensional images.ResultsThe most common morphology was a single root (67%), followed by two roots (30%), and three roots (3%). Regarding the canal morphology, most teeth (65%) contained two canals, followed by 30% with one canal, and 5% with three canals. One orifice was observed in 55% of teeth, and two orifices were detected in 45% of teeth. According to the Vertucci classification, the most common canal types were IV and V (both found in 23% of teeth), followed by type I (17%), type III (9%), type II (7%), and type VII (2%). Additional types that were inconsistent with the Vertucci classification were recorded in 19% of teeth.ConclusionThe root canal morphology of maxillary second premolars in the Saudi Arabian subpopulation is complex and requires cautious evaluation prior to endodontic treatment.

Prevalence and morphometric analysis of three-rooted mandibular first molars in a Brazilian subpopulation.

ABSTRACTThe knowledge of the internal anatomy of three-rooted mandibular molars may help clinicians to diagnose and plan the root canal treatment in order to provide adequate therapy when this variation is present.Objectives:To determine the prevalence of three-rooted mandibular molars in a Brazilian population using cone beam computed tomography (CBCT) and to analyze the anatomy of mandibular first molars with three roots through micro-CT.Material and Methods:CBCT images of 116 patients were reviewed to determine the prevalence of three-rooted first mandibular molars in a Brazilian subpopulation. Furthermore, with the use of micro-CT, 55 extracted three-rooted mandibular first molars were scanned and reconstructed to assess root length, distance between canal orifices, apical diameter, Vertucci's classification, presence of apical delta, number of foramina and furcations, lateral and accessory canals. The distance between the orifice on the pulp chamber floor and the beginning of the curvature and the angle of canal curvature were analyzed in the distolingual root. Data were compared using the Kruskal-Wallis test (α=0.05).Results:The prevalence of three-rooted mandibular first molars was of 2.58%. Mesial roots showed complex distribution of the root canal system in comparison to the distal roots. The median of major diameters of mesiobuccal, mesiolingual and single mesial canals were: 0.34, 0.41 and 0.60 mm, respectively. The higher values of major diameters were found in the distobuccal canals (0.56 mm) and the lower diameters in the distolingual canals (0.29 mm). The lowest orifice distance was found between the mesial canals (MB-ML) and the highest distance between the distal root canals (DB-DL). Almost all distal roots had one root canal and one apical foramen with few accessory canals.Conclusions:Distolingual root generally has short length, severe curvature and a single root canal with low apical diameter.

Endodontic Management of Variants of C-Shaped Canal: Case Series

A thorough knowledge of the root canal morphology is required for successful endodontic therapy. One of the most important anatomic variations is the C-shaped configuration of the root canal system. The presence of high incidence of transverse anastomoses, lateral canals, and apical deltas makes it difficult to clean and seal the root canal system in these teeth and may complicate endodontic interventions. Meticulous mechanical and chemical debridement of the canal space with additional efforts is essential for complete elimination of pulpal pathology in the anatomical irregularities. Obturation of the canal space also requires special attention as obtaining a three dimensional fill of a C-shaped canal may prove to be a problem due to the various intricacies present within the root canal system. Hence, this case series presents various types of C-shaped canal morphologies of mandibular second molars and their management.

Root canal anatomy of mandibular first premolars in an Emirati subpopulation: A laboratory study.

Objective:The purpose of this study was to determine the root canal anatomy of mandibular first premolar teeth in an Emirati subpopulation using a decalcification and clearing method.Materials and Methods:One hundred permanent mandibular first premolar teeth extracted for orthodontic purposes from an Emirati subpopulation from the United Arab Emirates were used for this study. They were subjected to decalcification and clearing. The tooth length, the canal orifice shape, mesial invagination, canal pattern, the location of apex, presence of lateral canals, and intercanal communications were determined.Results:The most common canal pattern was the Vertucci Type I (65%) followed by Type V (14%) and Type IV (13%). The most common type of canal orifice seen was the oval shape (36%) followed by the round shape (25%). Mesial invaginations were seen in 44% of the teeth. The mean tooth length was 19.9 mm, and apical deltas were seen in 24% of teeth.Conclusion:The Vertucci Type I canal pattern was the most prevalent in the mandibular first premolars while the occurrence of multiple canals was noted in 35% of this population.

Endodontic management of middle mesial canal in mandibular first molar

Deviations from the norm such as multiple orifices, apical deltas, accessory canals, and other variations are frequent in the roots of the posterior teeth. Two clinical reports of mandibular molars are presented in which three canals in the mesial roots were treated endodontically. Review of the literature encountered a prevalence ranging from 1% to 15%. Clinically, the third canal is difficult to find and exhibits a very variable morphology, which may present anastomosis with the other canals.

Micro-CT evaluation of C-shaped mandibular first premolars in a Brazilian subpopulation.

To describe morphometric aspects of the internal anatomy of C-shaped mandibular premolars from a Brazilian subpopulation using micro-CT analysis. First mandibular premolars with radicular grooves (n=123) were scanned using a micro-computed tomography system. After cross-section analysis, 83 specimens were identified with a C-shaped canal and selected for micro-CT analysis. Number and location of canals according to Vertucci's classification, distances between anatomic landmarks, occurrence of apical deltas, furcation canals, prevalence of C-shaped cross-sections at five levels as well as 2-dimensional analysis (Area, perimeter, roundness, aspect ratio, major and minor diameters) were performed for the more prevalent anatomical features. Data were compared statistically using Kruskal-Wallis tests (α=0.05). The more prevalent anatomical types according to Vertucci's classification were Type I (13%), III (8%), V (37%) and VII (2%). Mean distances from the furcation to the cemento-enamel junction were in the range of 5.36-5.65mm. Apical deltas and furcation canals were present in 36 (43%) and 27 (33%) specimens, respectively. C-shaped cross-sections were more prevalent at the middle (56%) and apical middle levels (81%). Overall, significant differences were found in the 2-dimensional analyses between single canals at the apical third and buccal and lingual canals of Vertucci's V classification (P<0.05). In this Brazilian subpopulation, C-shaped canal configuration of the root canal system was found in 67% of extracted first mandibular premolars with radicular grooves. Vertucci's types I and V were the most prevalent anatomical variations. C-shaped cross-sections were more prevalent in the middle third, and the presence of apical deltas was the most common feature in the apical third.

Scanning Electron Microscopic Evaluation of Tooth Root Apices in the Dog

External and internal ultramicroscopic characteristics of the tooth root apex in dogs were determined. Thirty teeth (16 maxillary fourth premolars, 7 mandibular first molars, and 7 maxillary canines) were examined. Teeth were obtained from 9 dogs with a total of 59 roots evaluated. Roots were sectioned perpendicular to the long axis (41), 3 to 7-mm from the apex, and others were sectioned longitudinally (18). Specimens were observed using scanning electron microscopy. The major diameter of 1,700 foramina and the depth of apical deltas were measured. The shape of the apex varied from round to elliptical and round-elliptical, with a regular or irregular surface. All root apices had many foramina, most (85.44 %) with a diameter &lt; 50-μm. The maximum foramen diameter was 234.19-μm. Great variation was observed in the size of the apical foramina. The internal aspect of the cementum at the apical level showed a “sieved plug”. The extension of the cementum within the root canal forming the apical delta measured 2 ± 0.4-mm.

Analysis of the apical constriction using micro-computed tomography and anatomical sections

ObjectivesThe aim of this study is to assess the morphology, the prevalence and the topography of the apical constriction (AC) through a tridimensional analysis and compare the results with the available data reported in the literature. Materials and methods15 teeth were selected. The teeth were intact and atraumatically extracted, without signs of radicular resorption or previous root canal treatments. Each tooth was scanned with the micro-computed tomography at a resolution of 9μm. Through computer reconstruction the roots were made transparent, in order to reveal the endodontic anatomy; two calibrated examiners assessed the prevalence and the morphology of the AC on two different projections for each tooth. The AC was classified as present (single, multiple, tapered) or absent (flaring, parallel, apical delta). Inter-rater agreement was computed applying Cohen's kappa. The distance between the AC and the apical foramen was determined by means of a digital ruler. Results and conclusion52.6% of the observed ACs was ambiguous (present on one projection but not on the other one). Only 21.0% of the canals showed a tridimensional AC (present on both projections). Inter-rater agreement was very good (k=0.839). The morphology, from greater to least, was flaring (25%), single (21.1%), parallel (21.1%), tapered (19.7%), apical delta (10.5%) and multiple (2.6%). Inter-rater agreement was again very good (kappa=0.869). Root canal anatomy as described in the literature is more conceptual than real. The presence of AC appears to be an exception rather than a canon.

The Radix Entomolaris and Paramolaris: A Micro–Computed Tomographic Study of 3-rooted Mandibular First Molars

IntroductionThe morphology of the supernumerary third root (radix) in mandibular first molars was examined by micro–computed tomography (μCT) scanning. MethodsNineteen permanent mandibular first molars with radix were scanned in a μCT device to evaluate their morphology with respect to root length, root curvature direction, location of radix, apical foramen, accessory canals and apical deltas, and distance between canal orifices as well as 2- and 3-dimensional parameters of the canals (number, area, roundness, major/minor diameter, volume, surface area, and structure model index). Quantitative data were analyzed by 1-way analysis of variance and the Tukey test (α = 0.05). ResultsThe mean length of the mesial, distal, and radix roots was 20.36 ± 1.73 mm, 20.0 ± 1.83 mm, and 18.09 ± 1.68 mm, respectively. The radix was located distolingually (n = 16), mesiolingually (n = 1), and distobuccally (n = 2). In a proximal view, most radix roots had a severe curvature with buccal orientation and a buccally displaced apical foramen. The spatial configuration of the canal orifices on the pulp chamber floor was mostly in a trapezoidal shape. The radix root canal orifice was usually covered by a dentinal projection. The radix differed significantly from the mesial and distal roots for all evaluated 3-dimensional parameters (P < .05). The radix canal had a more circular shape in the apical third, and the mean size of the minor diameter 1 mm short of the foramen was 0.25 ± 0.10 mm. ConclusionsThe radix root is an important and challenging anatomic variation of mandibular first molars, which usually has a severe curvature with a predominantly distolingual location, and a narrow root canal with difficult access.

Root canal configuration of permanent maxillary first molar in Khasi population of Meghalaya: An in vitro study.

Aims and Objective:To investigate the root canal configuration of permanent maxillary first molar in Khasi population of Meghalaya.Material and Methods:Sixty (60) permanent maxillary first molars collected from patients of Khasi population of Meghalaya were studied using canal staining and clearing technique. Observations of the number of roots, root canal configuration, lateral canal, apical delta, and presence of the additional type of canals were made.Results:Based on Vertucci's classification the different types of canal identified are: Mesiobuccal root, Type I (28.3%), Type II (28.3%), Type IV (30.0%), Type V (5.0%), Type VI (6.7%), and an additional type of canal (2-1-2-1-2; 1.7%) were observed. The distobuccal root displayed Type I (95%), Type II (1.7%), Type V (3.3%). The most prevalent canal configuration in the palatal roots is Type I (98.3%), Type II (1.7%).Conclusion:In Khasi population of Meghalaya, the most prevalent root canal configuration in the mesiobuccal root is Type IV followed by Type I and Type II. MB2 canals are present in more than 65% cases. In palatal and distobuccal roots, Type I configuration is present in most cases. Racial divergence may be responsible for such variations.